.env

@@ -1,10 +0,0 @@
-POSTGRES_USER=thoughts_user
-POSTGRES_PASSWORD=postgres
-POSTGRES_DB=thoughts_db
-
-HOST=0.0.0.0
-PORT=8000
-DATABASE_URL="postgresql://thoughts_user:postgres@database/thoughts_db"
-PREFORK=1
-AUTH_SECRET=secret
-BASE_URL=http://0.0.0.0

.env.example

@@ -1,3 +1,28 @@
-POSTGRES_USER=thoughts_user
+# Database (PostgreSQL required)
-POSTGRES_PASSWORD=postgres
+DATABASE_URL=postgres://postgres:password@localhost:5432/thoughts
-POSTGRES_DB=thoughts_db
+
+# Authentication
+JWT_SECRET=change-me
+
+# Public base URL — used for ActivityPub actor URLs and canonical links
+BASE_URL=http://localhost:3000
+
+# Optional
+HOST=0.0.0.0
+PORT=3000
+
+# CORS — comma-separated allowed origins, or * for permissive (default: *)
+CORS_ORIGINS=*
+# CORS_ORIGINS=https://your-nextjs-app.example.com
+
+# Rate limiting — max requests per minute per IP (disabled by default)
+# RATE_LIMIT=60
+ALLOW_REGISTRATION=true   # set to false to disable new sign-ups
+RUST_ENV=development      # set to "production" to disable AP debug mode
+
+# NATS event bus (optional — federation and notifications still work without it,
+# but events will not be delivered to the worker)
+# NATS_URL=nats://localhost:4222
+
+# Logging
+RUST_LOG=info

.gitea/workflows/deploy.yml

@@ -1,41 +1,19 @@
-name: Build and Deploy Thoughts
+name: deploy
 
 on:
-  push:
-    branches:
-      - master
   workflow_dispatch:
 
 jobs:
-  build-and-deploy-local:
+  deploy:
     runs-on: ubuntu-latest
-    
     steps:
-      - name: Checkout Code
+      - name: Deploy via SSH
-        uses: actions/checkout@v3
+        uses: appleboy/ssh-action@v1
-
+        with:
-      - name: Create .env file
+          host: ${{ secrets.DEPLOY_HOST }}
-        run: |
+          username: ${{ secrets.DEPLOY_USER }}
-          echo "POSTGRES_USER=${{ secrets.POSTGRES_USER }}" >> .env
+          key: ${{ secrets.DEPLOY_KEY }}
-          echo "POSTGRES_PASSWORD=${{ secrets.POSTGRES_PASSWORD }}" >> .env
+          script: |
-          echo "POSTGRES_DB=${{ secrets.POSTGRES_DB }}" >> .env
+            docker pull registry.gabrielkaszewski.dev/thoughts:latest
-          echo "AUTH_SECRET=${{ secrets.AUTH_SECRET }}" >> .env
+            docker pull registry.gabrielkaszewski.dev/thoughts-frontend:latest
-          echo "NEXT_PUBLIC_API_URL=${{ secrets.NEXT_PUBLIC_API_URL }}" >> .env
+            docker compose -f /opt/thoughts/docker-compose.yml up -d
-
-      - name: Build Docker Images Manually
-        run: |
-          docker build --target runtime -t thoughts-backend:latest ./thoughts-backend
-          docker build --target release -t thoughts-frontend:latest --build-arg NEXT_PUBLIC_API_URL=${{ secrets.NEXT_PUBLIC_API_URL }} ./thoughts-frontend
-          docker build -t custom-proxy:latest ./nginx
-
-      - name: Deploy with Docker Compose
-        run: |
-          docker compose -f compose.prod.yml down
-
-          POSTGRES_USER=${{ secrets.POSTGRES_USER }} \
-          POSTGRES_PASSWORD=${{ secrets.POSTGRES_PASSWORD }} \
-          POSTGRES_DB=${{ secrets.POSTGRES_DB }} \
-          AUTH_SECRET=${{ secrets.AUTH_SECRET }} \
-          docker compose -f compose.prod.yml up -d
-
-          docker image prune -f

.gitea/workflows/lint.yml

@@ -0,0 +1,24 @@
+name: lint
+
+on:
+  push:
+    branches: ["**"]
+  pull_request:
+
+jobs:
+  lint:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: dtolnay/rust-toolchain@stable
+        with:
+          components: rustfmt, clippy
+
+      - uses: Swatinem/rust-cache@v2
+
+      - name: fmt
+        run: cargo fmt --all -- --check
+
+      - name: clippy
+        run: cargo clippy --workspace --all-targets -- -D warnings

.gitea/workflows/test.yml

@@ -0,0 +1,52 @@
+name: test
+
+on:
+  push:
+    branches: ["**"]
+  pull_request:
+
+jobs:
+  # Unit tests — no database required.
+  # All business logic is tested via TestStore (in-memory port implementations).
+  unit:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@v2
+      - name: unit tests
+        run: |
+          cargo test --workspace \
+            --exclude postgres \
+            --exclude postgres-federation \
+            --exclude postgres-search
+
+  # Integration tests — require a real PostgreSQL instance.
+  # These test that the SQL queries in the adapter crates are correct.
+  integration:
+    runs-on: ubuntu-latest
+    services:
+      postgres:
+        image: postgres:16
+        env:
+          POSTGRES_PASSWORD: postgres
+          POSTGRES_DB: thoughts_test
+        options: >-
+          --health-cmd pg_isready
+          --health-interval 10s
+          --health-timeout 5s
+          --health-retries 5
+        ports:
+          - 5432:5432
+    env:
+      DATABASE_URL: postgres://postgres:postgres@localhost:5432/thoughts_test
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@stable
+      - uses: Swatinem/rust-cache@v2
+      - name: integration tests
+        run: |
+          cargo test \
+            -p postgres \
+            -p postgres-federation \
+            -p postgres-search

.githooks/pre-commit

@@ -0,0 +1,13 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+echo "→ cargo fmt"
+if ! cargo fmt --all -- --check; then
+    echo "  run 'cargo fmt --all' to fix formatting"
+    exit 1
+fi
+
+echo "→ cargo clippy"
+if ! cargo clippy --workspace -- -D warnings; then
+    exit 1
+fi

.gitignore

@@ -1,3 +1,3 @@
-backend-codebase.txt
-frontend-codebase.txt
 .env
+
+/target

API Design.md

@@ -1,165 +0,0 @@
-# **Thoughts \- API Design (Version 1\)**
-
-## **1\. Overview**
-
-This document specifies the RESTful API for the Thoughts platform.
-
-* **Base URL:** /api/v1  
-* **Data Format:** All requests and responses will be in JSON format.  
-* **Authentication:** The API uses two primary methods for authentication:  
-  1. **JWT (JSON Web Tokens):** For the official web client. The POST /api/v1/auth/login endpoint returns a short-lived JWT. This token must be included in the Authorization: Bearer \<token\> header for all subsequent authenticated requests.  
-  2. **API Keys:** For third-party applications. Users can generate long-lived API keys. These keys must be included in the Authorization: ApiKey \<key\> header.
-
-## **2\. API Endpoints**
-
-### **Auth Endpoints**
-
-**POST /auth/register**
-
-* **Description:** Creates a new user account.  
-* **Authentication:** Public.  
-* **Request Body:**  
-  {  
-    "username": "frutiger",  
-    "email": "aero@example.com",  
-    "password": "strongpassword123"  
-  }
-
-* **Success Response:** 201 Created with the new User object (password omitted).  
-* **Error Responses:** 400 Bad Request (invalid input), 409 Conflict (username or email already exists).
-
-**POST /auth/login**
-
-* **Description:** Authenticates a user and returns a JWT.  
-* **Authentication:** Public.  
-* **Request Body:**  
-  {  
-    "username": "frutiger",  
-    "password": "strongpassword123"  
-  }
-
-* **Success Response:** 200 OK with a JWT.  
-  {  
-    "token": "eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9..."  
-  }
-
-* **Error Responses:** 400 Bad Request, 401 Unauthorized.
-
-### **User & Profile Endpoints**
-
-**GET /users/{username}**
-
-* **Description:** Retrieves the public profile of a user.  
-* **Authentication:** Public.  
-* **Success Response:** 200 OK with a public User object.
-
-**GET /users/me**
-
-* **Description:** Retrieves the full profile of the currently authenticated user (including private details like email).  
-* **Authentication:** Required (JWT).  
-* **Success Response:** 200 OK with the full User object.
-
-**PUT /users/me**
-
-* **Description:** Updates the profile of the currently authenticated user.  
-* **Authentication:** Required (JWT).  
-* **Request Body:**  
-  {  
-    "displayName": "Frutiger Aero Fan",  
-    "bio": "Est. 2004",  
-    "avatarUrl": "https://...",  
-    "headerUrl": "https://...",  
-    "customCss": "body { background: blue; }",  
-    "topFriends": \["username1", "username2"\]  
-  }
-
-* **Success Response:** 200 OK with the updated User object.  
-* **Error Responses:** 400 Bad Request.
-
-### **Thoughts (Posts) Endpoints**
-
-**POST /thoughts**
-
-* **Description:** Creates a new thought.  
-* **Authentication:** Required (JWT or API Key).  
-* **Request Body:**  
-  {  
-    "content": "This is my first thought\! \#welcome"  
-  }
-
-* **Success Response:** 201 Created with the new Thought object.  
-* **Error Responses:** 400 Bad Request (e.g., content \> 128 chars).
-
-**GET /users/{username}/thoughts**
-
-* **Description:** Retrieves all thoughts for a specific user, paginated.  
-* **Authentication:** Public.  
-* **Success Response:** 200 OK with an array of Thought objects.
-
-**DELETE /thoughts/{id}**
-
-* **Description:** Deletes a thought. The user must be the author.  
-* **Authentication:** Required (JWT or API Key).  
-* **Success Response:** 204 No Content.  
-* **Error Responses:** 403 Forbidden, 404 Not Found.
-
-### **Social Endpoints**
-
-**POST /users/{username}/follow**
-
-* **Description:** Follows a user.  
-* **Authentication:** Required (JWT).  
-* **Success Response:** 204 No Content.  
-* **Error Responses:** 404 Not Found, 409 Conflict (already following).
-
-**DELETE /users/{username}/follow**
-
-* **Description:** Unfollows a user.  
-* **Authentication:** Required (JWT).  
-* **Success Response:** 204 No Content.  
-* **Error Responses:** 404 Not Found.
-
-**GET /feed**
-
-* **Description:** Retrieves the main feed for the authenticated user, paginated.  
-* **Authentication:** Required (JWT).  
-* **Success Response:** 200 OK with an array of Thought objects from followed users.
-
-### **Discovery Endpoints**
-
-**GET /tags/popular**
-
-* **Description:** Retrieves a list of currently popular tags.  
-* **Authentication:** Public.  
-* **Success Response:** 200 OK with an array of tag strings.
-
-**GET /tags/{tagName}**
-
-* **Description:** Retrieves a feed of all thoughts with a specific tag, paginated.  
-* **Authentication:** Public.  
-* **Success Response:** 200 OK with an array of Thought objects.
-
-## **3\. Data Models**
-
-**User Object (Public)**
-
-{  
-  "username": "frutiger",  
-  "displayName": "Frutiger Aero Fan",  
-  "bio": "Est. 2004",  
-  "avatarUrl": "https://...",  
-  "headerUrl": "https://...",  
-  "customCss": "body { background: blue; }",  
-  "topFriends": \["username1", "username2"\],  
-  "joinedAt": "2024-01-01T12:00:00Z"  
-}
-
-**Thought Object**
-
-{  
-  "id": "uuid-v4-string",  
-  "authorUsername": "frutiger",  
-  "content": "This is my first thought\! \#welcome",  
-  "tags": \["welcome"\],  
-  "createdAt": "2024-01-01T12:01:00Z"  
-}  

Cargo.toml

@@ -0,0 +1,54 @@
+[workspace]
+members = [
+    "crates/domain",
+    "crates/application",
+    "crates/api-types",
+    "crates/presentation",
+    "crates/bootstrap",
+    "crates/worker",
+    "crates/adapters/postgres",
+    "crates/adapters/postgres-search",
+    "crates/adapters/postgres-federation",
+    "crates/adapters/activitypub-base",
+    "crates/adapters/activitypub",
+    "crates/adapters/auth",
+    "crates/adapters/nats",
+    "crates/adapters/event-payload",
+    "crates/adapters/event-transport",
+]
+resolver = "2"
+
+[workspace.dependencies]
+tokio = { version = "1.0", features = ["macros", "net", "rt", "rt-multi-thread", "sync", "time"] }
+serde = { version = "1.0", features = ["derive"] }
+serde_json = "1.0"
+anyhow = "1.0"
+thiserror = "2.0"
+tracing = "0.1"
+tracing-subscriber = { version = "0.3", features = ["env-filter"] }
+async-trait = "0.1"
+uuid = { version = "1.0", features = ["v4", "v5", "serde"] }
+chrono = { version = "0.4", features = ["serde"] }
+sqlx = { version = "0.8", features = ["runtime-tokio-rustls", "postgres", "uuid", "chrono", "macros"] }
+axum = { version = "0.8", features = ["macros"] }
+tower-http = { version = "0.6", features = ["cors", "trace"] }
+futures = "0.3"
+dotenvy = "0.15"
+async-nats = "0.48"
+async-stream = "0.3"
+reqwest = { version = "0.13", features = ["json"] }
+url = { version = "2", features = ["serde"] }
+
+presentation     = { path = "crates/presentation" }
+domain           = { path = "crates/domain" }
+application      = { path = "crates/application" }
+api-types        = { path = "crates/api-types" }
+postgres         = { path = "crates/adapters/postgres" }
+postgres-search  = { path = "crates/adapters/postgres-search" }
+postgres-federation = { path = "crates/adapters/postgres-federation" }
+activitypub-base = { path = "crates/adapters/activitypub-base" }
+activitypub      = { path = "crates/adapters/activitypub" }
+auth             = { path = "crates/adapters/auth" }
+nats             = { path = "crates/adapters/nats" }
+event-payload    = { path = "crates/adapters/event-payload" }
+event-transport  = { path = "crates/adapters/event-transport" }

Database schema.md

@@ -1,114 +0,0 @@
-# **Thoughts \- Database Schema (PostgreSQL)**
-
-## **1\. Overview**
-
-This document outlines the table structure for the Thoughts platform using PostgreSQL. The design uses UUIDs for primary keys to facilitate decentralization and prevent enumeration attacks. All timestamps are stored with time zones (TIMESTAMPTZ).
-
-## **2\. Schema Diagram (ERD)**
-
-\+-------------+      \+--------------+      \+--------------+  
-|    users    |\<--+--|   thoughts   |---+--|\> thought\_tags |  
-\+-------------+   |  \+--------------+   |  \+--------------+  
-      |           |                       |        ^  
-      |           |                       |        |  
-      |           |  \+--------------+     |  \+--------------+  
-      \+--------+--+--|\>   follows    |\<--+-+--|     tags     |  
-      |        |     \+--------------+     |  \+--------------+  
-      |        |                          |  
-      v        |                          |  
-\+-------------+  |                          |  
-| top\_friends |\<-+                          |  
-\+-------------+                           |  
-      |                                     |  
-      v                                     |  
-\+-------------+                           |  
-|  api\_keys   |\<--------------------------+  
-\+-------------+
-
-*(Note: Arrows denote foreign key relationships)*
-
-## **3\. Table Definitions**
-
-### **users**
-
-Stores user account and profile information.
-
-| Column Name | Data Type | Constraints | Description |
-| :---- | :---- | :---- | :---- |
-| id | UUID | PRIMARY KEY, DEFAULT gen\_random\_uuid() | Unique identifier for the user. |
-| username | VARCHAR(32) | NOT NULL, UNIQUE | The user's handle. |
-| email | VARCHAR(255) | NOT NULL, UNIQUE | The user's email address. |
-| password\_hash | TEXT | NOT NULL | Hashed password (using Argon2 or bcrypt). |
-| display\_name | VARCHAR(50) | NULL | User's public display name. |
-| bio | VARCHAR(160) | NULL | User's public biography. |
-| avatar\_url | TEXT | NULL | URL to the user's avatar image. |
-| header\_url | TEXT | NULL | URL to the user's header image. |
-| custom\_css | TEXT | NULL | User's custom profile CSS. |
-| created\_at | TIMESTAMPTZ | NOT NULL, DEFAULT NOW() | Timestamp of account creation. |
-| updated\_at | TIMESTAMPTZ | NOT NULL, DEFAULT NOW() | Timestamp of the last profile update. |
-
-### **thoughts**
-
-Stores the content of each post.
-
-| Column Name | Data Type | Constraints | Description |
-| :---- | :---- | :---- | :---- |
-| id | UUID | PRIMARY KEY, DEFAULT gen\_random\_uuid() | Unique identifier for the thought. |
-| user\_id | UUID | NOT NULL, REFERENCES users(id) | The ID of the authoring user. |
-| content | VARCHAR(128) | NOT NULL | The text content of the thought. |
-| created\_at | TIMESTAMPTZ | NOT NULL, DEFAULT NOW() | Timestamp of when the thought was posted. |
-
-### **follows**
-
-A join table representing the follower/following relationship.
-
-| Column Name | Data Type | Constraints | Description |
-| :---- | :---- | :---- | :---- |
-| follower\_id | UUID | NOT NULL, REFERENCES users(id) | The user who is initiating the follow. |
-| following\_id | UUID | NOT NULL, REFERENCES users(id) | The user who is being followed. |
-|  |  | PRIMARY KEY (follower\_id, following\_id) | Ensures a user can't follow someone twice. |
-
-### **top\_friends**
-
-Stores the ordered list of a user's "Top Friends".
-
-| Column Name | Data Type | Constraints | Description |
-| :---- | :---- | :---- | :---- |
-| user\_id | UUID | NOT NULL, REFERENCES users(id) | The owner of this "Top Friends" list. |
-| friend\_id | UUID | NOT NULL, REFERENCES users(id) | The user being displayed as a friend. |
-| position | SMALLINT | NOT NULL | The order (1-8) of the friend on the list. |
-|  |  | PRIMARY KEY (user\_id, friend\_id) | Ensures a user can't be in the list twice. |
-|  |  | UNIQUE (user\_id, position) | Ensures positions are not duplicated. |
-
-### **tags and thought\_tags (for hashtags)**
-
-* **tags**: Stores unique tag names.  
-* **thought\_tags**: A join table linking thoughts to tags.
-
-#### **tags**
-
-| Column Name | Data Type | Constraints | Description |
-| :---- | :---- | :---- | :---- |
-| id | SERIAL | PRIMARY KEY | Unique ID for the tag. |
-| name | VARCHAR(50) | NOT NULL, UNIQUE | The tag name (e.g., "welcome"). |
-
-#### **thought\_tags**
-
-| Column Name | Data Type | Constraints | Description |
-| :---- | :---- | :---- | :---- |
-| thought\_id | UUID | NOT NULL, REFERENCES thoughts(id) | The ID of the thought. |
-| tag\_id | INTEGER | NOT NULL, REFERENCES tags(id) | The ID of the tag. |
-|  |  | PRIMARY KEY (thought\_id, tag\_id) | Prevents duplicate tags per post. |
-
-### **api\_keys**
-
-Stores hashed API keys for users.
-
-| Column Name | Data Type | Constraints | Description |
-| :---- | :---- | :---- | :---- |
-| id | UUID | PRIMARY KEY, DEFAULT gen\_random\_uuid() | Unique identifier for the API key. |
-| user\_id | UUID | NOT NULL, REFERENCES users(id) | The user who owns this key. |
-| key\_hash | TEXT | NOT NULL, UNIQUE | The hashed value of the API key. |
-| name | VARCHAR(50) | NOT NULL | A user-provided name for the key. |
-| created\_at | TIMESTAMPTZ | NOT NULL, DEFAULT NOW() | Timestamp of when the key was created. |
-

Dockerfile

@@ -0,0 +1,58 @@
+# ----- build -----
+FROM rust:slim-bookworm AS builder
+
+WORKDIR /build
+
+# Cache dependency compilation separately from source
+COPY Cargo.toml Cargo.lock ./
+COPY crates/adapters/activitypub/Cargo.toml       crates/adapters/activitypub/Cargo.toml
+COPY crates/adapters/activitypub-base/Cargo.toml  crates/adapters/activitypub-base/Cargo.toml
+COPY crates/adapters/auth/Cargo.toml              crates/adapters/auth/Cargo.toml
+COPY crates/adapters/event-payload/Cargo.toml     crates/adapters/event-payload/Cargo.toml
+COPY crates/adapters/event-transport/Cargo.toml   crates/adapters/event-transport/Cargo.toml
+COPY crates/adapters/nats/Cargo.toml              crates/adapters/nats/Cargo.toml
+COPY crates/adapters/postgres/Cargo.toml          crates/adapters/postgres/Cargo.toml
+COPY crates/adapters/postgres-federation/Cargo.toml crates/adapters/postgres-federation/Cargo.toml
+COPY crates/adapters/postgres-search/Cargo.toml   crates/adapters/postgres-search/Cargo.toml
+COPY crates/api-types/Cargo.toml                  crates/api-types/Cargo.toml
+COPY crates/application/Cargo.toml                crates/application/Cargo.toml
+COPY crates/bootstrap/Cargo.toml                  crates/bootstrap/Cargo.toml
+COPY crates/domain/Cargo.toml                     crates/domain/Cargo.toml
+COPY crates/presentation/Cargo.toml               crates/presentation/Cargo.toml
+COPY crates/worker/Cargo.toml                     crates/worker/Cargo.toml
+
+# Stub every crate so cargo can resolve and fetch deps without real source
+RUN find crates -name "Cargo.toml" | sed 's|/Cargo.toml||' | \
+    xargs -I{} sh -c 'mkdir -p {}/src && echo "fn main(){}" > {}/src/main.rs && echo "" > {}/src/lib.rs'
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    pkg-config \
+    libssl-dev \
+ && rm -rf /var/lib/apt/lists/*
+
+RUN cargo fetch
+
+# Now copy real source and build
+COPY crates ./crates
+
+RUN cargo build --release -p bootstrap -p worker
+
+# ----- runtime -----
+FROM debian:bookworm-slim
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    ca-certificates \
+    libssl3 \
+    wget \
+ && rm -rf /var/lib/apt/lists/*
+
+WORKDIR /app
+
+COPY --from=builder /build/target/release/thoughts        ./thoughts
+COPY --from=builder /build/target/release/thoughts-worker ./thoughts-worker
+
+EXPOSE 3000
+
+ENV RUST_LOG=info
+
+CMD ["./thoughts"]

LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2026 Gabriel Kaszewski
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

README.md

@@ -0,0 +1,146 @@
+# Thoughts
+
+A self-hosted microblogging server with full ActivityPub federation. Write short posts, follow people on Mastodon and other Fediverse servers, and receive their posts in your feed. Built in Rust with a Next.js frontend.
+
+## Features
+
+- Short-form posts (thoughts) with replies, boosts, and likes
+- Full ActivityPub federation — follow/unfollow remote actors, accept/reject followers, federated content broadcast as `Note` objects, paginated outbox, NodeInfo discovery, WebFinger, shared inbox, actor profile sync
+- **Remote actor discovery** — search by `@user@instance` handle, view full remote profiles (bio, banner, profile fields, posts, followers, following tabs), follow from within the UI
+- **Worker-backed remote caches** — remote posts and follower/following lists are fetched by the NATS worker and cached locally; profiles populate on first visit and refresh in the background
+- Content negotiation at `GET /users/{username}` — serves ActivityPub actor JSON or REST profile based on `Accept` header
+- Federation moderation — per-instance domain blocking, per-user actor blocking with `Block` activity delivery, delivery filter excludes blocked actors and blocked-domain inboxes
+- Async event fan-out via NATS JetStream — notifications and AP delivery run in a separate worker process; pull consumer with 1-hour TTL caching
+- JWT authentication (Bearer token)
+- OpenAPI documentation at `/docs` (Swagger UI) and `/scalar` (Scalar)
+- Full-text search over thoughts and users via PostgreSQL trigram indexes
+- Top friends — pin up to 5 users as highlighted contacts
+- API keys for third-party client access
+- Home feed, public feed, and per-user thought timelines
+
+## Architecture
+
+Hexagonal (Ports & Adapters) with Domain-Driven Design:
+
+```
+domain              — pure types and port trait definitions, no external deps
+application         — use cases and event processing services (business logic)
+api-types           — shared REST API request/response DTOs
+presentation        — Axum HTTP router, OpenAPI spec, composition root for the API process
+bootstrap           — binary: thoughts (API server)
+worker              — binary: thoughts-worker (event consumer — notifications, AP fan-out)
+adapters/
+  auth                 — JWT issuance and validation, Argon2 password hashing
+  postgres             — PostgreSQL repositories for all domain entities
+  postgres-search      — PostgreSQL trigram full-text search
+  postgres-federation  — PostgreSQL-backed federation repository
+  activitypub-base     — core ActivityPub protocol types, ActivityPubService, federation middleware
+  activitypub          — project-specific AP wiring (ThoughtsObjectHandler, inbox/outbox)
+  nats                 — NATS transport implementing Transport + MessageSource ports
+  event-payload        — shared event serialization DTOs
+  event-transport      — Transport trait + EventPublisherAdapter / MessageSource + EventConsumerAdapter
+```
+
+## Prerequisites
+
+- Rust stable (1.80+)
+- PostgreSQL 15+
+- NATS (optional — federation and notifications still work without it, events queue in-process)
+
+## Environment Variables
+
+Copy `.env.example` to `.env` and fill in your values:
+
+```env
+DATABASE_URL=postgres://postgres:password@localhost:5432/thoughts
+JWT_SECRET=change-me
+BASE_URL=http://localhost:3000
+NATS_URL=nats://localhost:4222   # optional
+```
+
+See `.env.example` for all available options.
+
+## Run
+
+```bash
+# API server (runs migrations automatically on startup)
+cargo run -p bootstrap
+
+# Event worker — federation fan-out and notifications (separate terminal)
+cargo run -p worker
+```
+
+Both processes share the same PostgreSQL database. The worker is optional but required for ActivityPub delivery to remote servers.
+
+## Test
+
+```bash
+# Unit tests — no database required
+cargo test -p application
+
+# Full workspace (requires DATABASE_URL pointing to a running PostgreSQL)
+cargo test --workspace
+```
+
+The `application` crate contains unit tests for all event services and use cases backed by in-memory fakes from `domain`'s `test-helpers` feature. These are the fastest feedback loop for business logic.
+
+## API
+
+All REST endpoints are under the root path. Authentication uses `Authorization: Bearer <token>` obtained from `POST /auth/login`.
+
+Interactive API documentation is available at runtime:
+
+- **Swagger UI** — `http://localhost:8000/docs`
+- **Scalar** — `http://localhost:8000/scalar`
+
+## Frontend
+
+The Next.js frontend lives in `thoughts-frontend/`. It requires two environment variables:
+
+```env
+NEXT_PUBLIC_API_URL=http://localhost:8000        # client-side requests
+NEXT_PUBLIC_SERVER_SIDE_API_URL=http://localhost:8000  # SSR requests
+```
+
+```bash
+cd thoughts-frontend
+bun install
+bun run dev   # http://localhost:3000
+```
+
+## Docker
+
+The backend image contains both `thoughts` (API server) and `thoughts-worker` (event processor). Run them as separate containers:
+
+```bash
+docker build -t thoughts .
+
+# API server
+docker run -p 8000:8000 \
+  -e DATABASE_URL=postgres://postgres:password@db:5432/thoughts \
+  -e JWT_SECRET=change-me \
+  -e BASE_URL=https://yourdomain.example.com \
+  -e NATS_URL=nats://nats:4222 \
+  thoughts
+
+# Event worker (same image, different entrypoint)
+docker run \
+  -e DATABASE_URL=postgres://postgres:password@db:5432/thoughts \
+  -e BASE_URL=https://yourdomain.example.com \
+  -e NATS_URL=nats://nats:4222 \
+  --entrypoint ./thoughts-worker \
+  thoughts
+
+# Frontend
+docker build -t thoughts-frontend \
+  --build-arg NEXT_PUBLIC_API_URL=https://api.yourdomain.example.com \
+  --build-arg NEXT_PUBLIC_SERVER_SIDE_API_URL=http://thoughts:8000 \
+  thoughts-frontend/
+docker run -p 3000:3000 thoughts-frontend
+```
+
+See `compose.yml` for a full local development stack.
+
+## License
+
+MIT License. See [LICENSE](LICENSE).

codebase-prompt.txt

@@ -1,2 +0,0 @@
-uvx files-to-prompt thoughts-backend -e toml -e rs -e md --ignore "*target" -o backend-codebase.txt
-uvx files-to-prompt thoughts-frontend -o frontend-codebase.txt --ignore "*node_modules" --ignore "*.lock"

compose.prod.yml

@@ -1,6 +1,6 @@
 services:
   database:
-    image: postgres:15-alpine
+    image: postgres:16-alpine
     container_name: thoughts-db
     restart: unless-stopped
     environment:
@@ -17,19 +17,21 @@ services:
     networks:
       - internal
 
-  backend:
+  api:
-    container_name: thoughts-backend
+    container_name: thoughts-api
-    image: thoughts-backend:latest
+    image: registry.gabrielkaszewski.dev/thoughts:latest
     restart: unless-stopped
     environment:
-      - RUST_LOG=info
+      RUST_LOG: info
-      - RUST_BACKTRACE=1
+      RUST_ENV: production
-      - DATABASE_URL=postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@database/${POSTGRES_DB}
+      DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@database/${POSTGRES_DB}
-      - HOST=0.0.0.0
+      HOST: 0.0.0.0
-      - PORT=8000
+      PORT: 8000
-      - PREFORK=1
+      JWT_SECRET: ${JWT_SECRET}
-      - AUTH_SECRET=${AUTH_SECRET}
+      BASE_URL: ${BASE_URL}
-      - BASE_URL=https://thoughts.gabrielkaszewski.dev
+      NATS_URL: nats://k_nats:4222
+      CORS_ORIGINS: ${CORS_ORIGINS:-*}
+      ALLOW_REGISTRATION: ${ALLOW_REGISTRATION:-false}
     depends_on:
       database:
         condition: service_healthy
@@ -40,34 +42,51 @@ services:
       retries: 5
     networks:
       - internal
+      - shared-services
+      - traefik
+    labels:
+      - "traefik.enable=true"
+      - "traefik.docker.network=traefik"
+      - "traefik.http.routers.thoughts-api.rule=Host(`api.thoughts.gabrielkaszewski.dev`)"
+      - "traefik.http.routers.thoughts-api.entrypoints=web,websecure"
+      - "traefik.http.routers.thoughts-api.tls.certresolver=letsencrypt"
+      - "traefik.http.routers.thoughts-api.service=thoughts-api"
+      - "traefik.http.services.thoughts-api.loadbalancer.server.port=8000"
+
+  worker:
+    container_name: thoughts-worker
+    image: registry.gabrielkaszewski.dev/thoughts:latest
+    entrypoint: ["./thoughts-worker"]
+    restart: unless-stopped
+    environment:
+      RUST_LOG: info
+      DATABASE_URL: postgresql://${POSTGRES_USER}:${POSTGRES_PASSWORD}@database/${POSTGRES_DB}
+      BASE_URL: ${BASE_URL}
+      NATS_URL: nats://k_nats:4222
+    depends_on:
+      database:
+        condition: service_healthy
+    networks:
+      - internal
+      - shared-services
 
   frontend:
     container_name: thoughts-frontend
-    image: thoughts-frontend:latest
+    image: registry.gabrielkaszewski.dev/thoughts-frontend:latest
     restart: unless-stopped
+    environment:
+      NEXT_PUBLIC_SERVER_SIDE_API_URL: http://api:8000
+      NEXT_PUBLIC_API_URL: https://api.thoughts.gabrielkaszewski.dev
+      PORT: 3000
+      HOSTNAME: 0.0.0.0
     depends_on:
-      - backend
+      api:
+        condition: service_healthy
     healthcheck:
       test: ["CMD", "curl", "-f", "http://localhost:3000"]
       interval: 10s
       timeout: 5s
       retries: 5
-    environment:
-      - NEXT_PUBLIC_SERVER_SIDE_API_URL=http://proxy/api
-      - PORT=3000
-      - HOSTNAME=0.0.0.0
-    networks:
-      - internal
-
-  proxy:
-    container_name: thoughts-proxy
-    image: custom-proxy:latest
-    restart: unless-stopped
-    depends_on:
-      frontend:
-        condition: service_healthy
-      backend:
-        condition: service_healthy
     networks:
       - internal
       - traefik
@@ -78,14 +97,16 @@ services:
       - "traefik.http.routers.thoughts.entrypoints=web,websecure"
       - "traefik.http.routers.thoughts.tls.certresolver=letsencrypt"
       - "traefik.http.routers.thoughts.service=thoughts"
-      - "traefik.http.services.thoughts.loadbalancer.server.port=80"
+      - "traefik.http.services.thoughts.loadbalancer.server.port=3000"
 
 volumes:
   postgres_data:
     driver: local
+
 networks:
+  shared-services:
+    external: true
   traefik:
-    name: traefik
     external: true
   internal:
     driver: bridge

compose.yml

@@ -1,77 +1,67 @@
 services:
-  database:
+  postgres:
-    image: postgres:15-alpine
+    image: postgres:16-alpine
-    container_name: thoughts-db
-    restart: unless-stopped
-    environment:
-      POSTGRES_USER: ${POSTGRES_USER}
-      POSTGRES_PASSWORD: ${POSTGRES_PASSWORD}
-      POSTGRES_DB: ${POSTGRES_DB}
-    volumes:
-      - postgres_data:/var/lib/postgresql/data
-    ports:
-      - "5433:5432"
-    healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U ${POSTGRES_USER} -d ${POSTGRES_DB}"]
-      interval: 10s
-      timeout: 5s
-      retries: 5
-
-  backend:
-    container_name: thoughts-backend
-    build:
-      context: ./thoughts-backend
-      dockerfile: Dockerfile
-    restart: unless-stopped
-    env_file:
-      - .env
-    environment:
-      - RUST_LOG=info
-      - RUST_BACKTRACE=1
-    depends_on:
-      database:
-        condition: service_healthy
-
-  frontend:
-    container_name: thoughts-frontend
-    build:
-      context: ./thoughts-frontend
-      dockerfile: Dockerfile
-      args:
-        NEXT_PUBLIC_API_URL: http://localhost/api
-    restart: unless-stopped
-    depends_on:
-      - backend
-    environment:
-      - NEXT_PUBLIC_SERVER_SIDE_API_URL=http://proxy/api
-
-  proxy:
-    container_name: thoughts-proxy
-    image: nginx:stable-alpine
-    restart: unless-stopped
-    ports:
-      - "80:80"
-    volumes:
-      - ./nginx/nginx.conf:/etc/nginx/conf.d/default.conf
-    depends_on:
-      - frontend
-      - backend
-
-  db_test:
-    image: postgres:15-alpine
-    container_name: thoughts-db-test
     environment:
       POSTGRES_USER: postgres
       POSTGRES_PASSWORD: postgres
-      POSTGRES_DB: postgres
+      POSTGRES_DB: thoughts
     ports:
-      - "5434:5432"
+      - "5432:5432"
+    volumes:
+      - postgres_data:/var/lib/postgresql/data
     healthcheck:
-      test: ["CMD-SHELL", "pg_isready -U postgres -d postgres"]
+      test: ["CMD-SHELL", "pg_isready -U postgres"]
-      interval: 10s
+      interval: 5s
       timeout: 5s
       retries: 5
 
+  nats:
+    image: nats:2-alpine
+    ports:
+      - "4222:4222"
+      - "8222:8222"   # monitoring endpoint
+    command: ["--jetstream", "--http_port", "8222"]
+
+  api:
+    build: .
+    ports:
+      - "8000:8000"
+    environment:
+      DATABASE_URL: postgres://postgres:postgres@postgres:5432/thoughts
+      JWT_SECRET: change-me-in-production
+      BASE_URL: http://localhost:8000
+      NATS_URL: nats://nats:4222
+      RUST_LOG: info
+    depends_on:
+      postgres:
+        condition: service_healthy
+      nats:
+        condition: service_started
+
+  worker:
+    build: .
+    entrypoint: ["./thoughts-worker"]
+    environment:
+      DATABASE_URL: postgres://postgres:postgres@postgres:5432/thoughts
+      BASE_URL: http://localhost:8000
+      NATS_URL: nats://nats:4222
+      RUST_LOG: info
+    depends_on:
+      postgres:
+        condition: service_healthy
+      nats:
+        condition: service_started
+
+  frontend:
+    build:
+      context: ./thoughts-frontend
+      args:
+        NEXT_PUBLIC_API_URL: http://localhost:8000
+        NEXT_PUBLIC_SERVER_SIDE_API_URL: http://api:8000
+    ports:
+      - "3000:3000"
+    depends_on:
+      - api
+
 volumes:
   postgres_data:
-    driver: local

crates/adapters/activitypub-base/Cargo.toml

@@ -0,0 +1,22 @@
+[package]
+name = "activitypub-base"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+tokio        = { workspace = true }
+futures      = { workspace = true }
+serde        = { workspace = true }
+serde_json   = { workspace = true }
+uuid         = { workspace = true }
+chrono       = { workspace = true }
+anyhow       = { workspace = true }
+tracing      = { workspace = true }
+async-trait  = { workspace = true }
+axum         = { workspace = true }
+reqwest      = { workspace = true }
+url          = { workspace = true }
+domain       = { workspace = true }
+
+activitypub_federation = "0.7.0-beta.11"
+enum_delegate          = "0.2"

crates/adapters/activitypub-base/src/activities.rs

@@ -0,0 +1,851 @@
+use activitypub_federation::{
+    config::Data,
+    fetch::object_id::ObjectId,
+    kinds::activity::{
+        AcceptType, CreateType, DeleteType, FollowType, RejectType, UndoType, UpdateType,
+    },
+    traits::Activity,
+};
+use serde::{Deserialize, Serialize};
+use url::Url;
+
+#[derive(Clone, Default, Debug, Serialize, Deserialize)]
+#[serde(rename = "Announce")]
+pub struct AnnounceType;
+
+#[derive(Clone, Debug, Deserialize, Serialize)]
+#[serde(rename = "Like")]
+pub struct LikeType;
+
+impl Default for LikeType {
+    fn default() -> Self {
+        Self
+    }
+}
+
+use crate::actors::DbActor;
+use crate::data::FederationData;
+use crate::error::Error;
+use crate::repository::{FollowerStatus, FollowingStatus};
+
+// --- Follow ---
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct FollowActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: FollowType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: ObjectId<DbActor>,
+}
+
+#[async_trait::async_trait]
+impl Activity for FollowActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let target_url = self.object.inner();
+        let target_domain = match (target_url.host_str(), target_url.port()) {
+            (Some(host), Some(port)) => format!("{}:{}", host, port),
+            (Some(host), None) => host.to_string(),
+            _ => {
+                return Err(Error::bad_request(anyhow::anyhow!(
+                    "invalid follow target URL"
+                )));
+            }
+        };
+        if target_domain != data.domain {
+            return Err(Error::bad_request(anyhow::anyhow!(
+                "follow target is not a local actor"
+            )));
+        }
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let domain = self.actor().host_str().unwrap_or("");
+        if data.federation_repo.is_domain_blocked(domain).await? {
+            tracing::info!(actor = %self.actor(), "ignoring activity from blocked domain");
+            return Ok(());
+        }
+        let _follower = self.actor.dereference(data).await?;
+        let local_actor = self.object.dereference(data).await?;
+
+        if data
+            .federation_repo
+            .is_actor_blocked(local_actor.user_id, self.actor.inner().as_str())
+            .await?
+        {
+            tracing::info!(actor = %self.actor.inner(), "ignoring follow from blocked actor");
+            return Ok(());
+        }
+
+        data.federation_repo
+            .add_follower(
+                local_actor.user_id,
+                self.actor.inner().as_str(),
+                FollowerStatus::Pending,
+                self.id.as_str(),
+            )
+            .await?;
+
+        tracing::info!(
+            follower = %self.actor.inner(),
+            local_user = %local_actor.user_id,
+            "follow request pending approval"
+        );
+        Ok(())
+    }
+}
+
+// --- Accept ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct AcceptActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: AcceptType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: FollowActivity,
+}
+
+#[async_trait::async_trait]
+impl Activity for AcceptActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        if self.actor.inner() != self.object.object.inner() {
+            return Err(Error::bad_request(anyhow::anyhow!(
+                "Accept actor does not match Follow target"
+            )));
+        }
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let domain = self.actor().host_str().unwrap_or("");
+        if data.federation_repo.is_domain_blocked(domain).await? {
+            tracing::info!(actor = %self.actor(), "ignoring activity from blocked domain");
+            return Ok(());
+        }
+        let local_user_id = crate::urls::extract_user_id_from_url(self.object.actor.inner())
+            .ok_or_else(|| Error::bad_request(anyhow::anyhow!("invalid actor URL in Follow")))?;
+        data.federation_repo
+            .update_following_status(
+                local_user_id,
+                self.actor.inner().as_str(),
+                FollowingStatus::Accepted,
+            )
+            .await?;
+
+        tracing::info!(remote_actor = %self.actor.inner(), "follow accepted by remote");
+        Ok(())
+    }
+}
+
+// --- Reject ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct RejectActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: RejectType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: FollowActivity,
+}
+
+#[async_trait::async_trait]
+impl Activity for RejectActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        if self.actor.inner() != self.object.object.inner() {
+            return Err(Error::bad_request(anyhow::anyhow!(
+                "Reject actor does not match Follow target"
+            )));
+        }
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let domain = self.actor().host_str().unwrap_or("");
+        if data.federation_repo.is_domain_blocked(domain).await? {
+            tracing::info!(actor = %self.actor(), "ignoring activity from blocked domain");
+            return Ok(());
+        }
+        if let Some(user_id) = crate::urls::extract_user_id_from_url(self.object.actor.inner()) {
+            data.federation_repo
+                .remove_following(user_id, self.actor.inner().as_str())
+                .await?;
+        }
+        tracing::info!(actor = %self.actor.inner(), "follow rejected");
+        Ok(())
+    }
+}
+
+// --- Undo ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct UndoActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: UndoType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: serde_json::Value,
+}
+
+#[async_trait::async_trait]
+impl Activity for UndoActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let domain = self.actor().host_str().unwrap_or("");
+        if data.federation_repo.is_domain_blocked(domain).await? {
+            tracing::info!(actor = %self.actor(), "ignoring Undo from blocked domain");
+            return Ok(());
+        }
+
+        let obj_type = self
+            .object
+            .get("type")
+            .and_then(|t| t.as_str())
+            .unwrap_or("");
+
+        match obj_type {
+            "Follow" => {
+                if let Some(obj_url) = self.object.get("object").and_then(|o| o.as_str())
+                    && let Ok(url) = Url::parse(obj_url)
+                    && let Some(user_id) = crate::urls::extract_user_id_from_url(&url)
+                {
+                    data.federation_repo
+                        .remove_follower(user_id, self.actor.inner().as_str())
+                        .await?;
+                }
+                data.object_handler
+                    .on_actor_removed(self.actor.inner())
+                    .await
+                    .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+                tracing::info!(actor = %self.actor.inner(), "unfollowed");
+            }
+            "Add" => {
+                let ap_id_str = self
+                    .object
+                    .get("object")
+                    .and_then(|o| o.get("id"))
+                    .and_then(|id| id.as_str())
+                    .or_else(|| self.object.get("id").and_then(|id| id.as_str()));
+
+                if let Some(ap_id_str) = ap_id_str
+                    && let Ok(ap_id) = Url::parse(ap_id_str)
+                {
+                    data.object_handler
+                        .on_delete(&ap_id, self.actor.inner())
+                        .await
+                        .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+                    tracing::info!(ap_id = %ap_id_str, "undo Add (watchlist remove)");
+                }
+            }
+            "Like" => {
+                if let Some(obj_url_str) = self.object.get("object").and_then(|o| o.as_str())
+                    && let Ok(obj_url) = Url::parse(obj_url_str)
+                    && obj_url.host_str().unwrap_or("") == data.domain
+                {
+                    data.object_handler
+                        .on_unlike(&obj_url, self.actor.inner())
+                        .await
+                        .unwrap_or_else(|e| {
+                            tracing::warn!(error = %e, "failed to process unlike");
+                        });
+                }
+                tracing::info!(actor = %self.actor.inner(), "received Undo(Like)");
+            }
+            other => {
+                tracing::debug!(kind = %other, "ignoring Undo of unknown activity type");
+            }
+        }
+
+        Ok(())
+    }
+}
+
+// --- Create ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct CreateActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: CreateType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: serde_json::Value,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub(crate) to: Vec<String>,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub(crate) cc: Vec<String>,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub(crate) bto: Vec<String>,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub(crate) bcc: Vec<String>,
+}
+
+#[async_trait::async_trait]
+impl Activity for CreateActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        if let Some(attributed_to) = self.object.get("attributedTo").and_then(|v| v.as_str())
+            && let Ok(attributed_url) = Url::parse(attributed_to)
+            && &attributed_url != self.actor.inner()
+        {
+            return Err(Error::bad_request(anyhow::anyhow!(
+                "Create actor does not match object attributedTo"
+            )));
+        }
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let domain = self.actor().host_str().unwrap_or("");
+        if data.federation_repo.is_domain_blocked(domain).await? {
+            tracing::info!(actor = %self.actor(), "ignoring activity from blocked domain");
+            return Ok(());
+        }
+        // Use the Note's own id, not the Create activity id (which ends in /activity).
+        // Delete activities reference the Note id, so they must match.
+        let ap_id = self
+            .object
+            .get("id")
+            .and_then(|v| v.as_str())
+            .and_then(|s| Url::parse(s).ok())
+            .unwrap_or_else(|| self.id.clone());
+        let actor_url = self.actor.inner().clone();
+        data.object_handler
+            .on_create(&ap_id, &actor_url, self.object)
+            .await
+            .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+        tracing::info!(actor = %actor_url, "received create activity");
+        Ok(())
+    }
+}
+
+// --- Delete ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct DeleteActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: DeleteType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: serde_json::Value,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub(crate) to: Vec<String>,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub(crate) cc: Vec<String>,
+}
+
+#[async_trait::async_trait]
+impl Activity for DeleteActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let actor_domain = self.actor.inner().host_str().unwrap_or("");
+        let object_domain = match &self.object {
+            serde_json::Value::String(s) => Url::parse(s)
+                .ok()
+                .and_then(|u| u.host_str().map(|h| h.to_string()))
+                .unwrap_or_default(),
+            serde_json::Value::Object(o) => o
+                .get("id")
+                .and_then(|v| v.as_str())
+                .and_then(|s| Url::parse(s).ok())
+                .and_then(|u| u.host_str().map(|h| h.to_string()))
+                .unwrap_or_default(),
+            _ => String::new(),
+        };
+        if !object_domain.is_empty() && actor_domain != object_domain {
+            return Err(Error::bad_request(anyhow::anyhow!(
+                "Delete actor domain does not match object domain"
+            )));
+        }
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let domain = self.actor().host_str().unwrap_or("");
+        if data.federation_repo.is_domain_blocked(domain).await? {
+            tracing::info!(actor = %self.actor(), "ignoring activity from blocked domain");
+            return Ok(());
+        }
+        let actor_url = self.actor.inner().clone();
+
+        // Extract object URL — handles plain string and Tombstone {"id":"...","type":"Tombstone"}
+        let object_url_str = match &self.object {
+            serde_json::Value::String(s) => s.clone(),
+            serde_json::Value::Object(o) => o
+                .get("id")
+                .and_then(|v| v.as_str())
+                .map(|s| s.to_string())
+                .unwrap_or_default(),
+            _ => String::new(),
+        };
+        let Ok(object_url) = Url::parse(&object_url_str) else {
+            tracing::warn!(actor = %actor_url, "Delete activity has unparseable object, ignoring");
+            return Ok(());
+        };
+
+        // Actor self-deletion: Mastodon sends Delete(actor_url) when an account is deleted.
+        if object_url == *self.actor.inner() {
+            data.object_handler
+                .on_actor_removed(&actor_url)
+                .await
+                .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+            tracing::info!(actor = %actor_url, "received Delete(actor) — remote account deleted");
+            return Ok(());
+        }
+
+        // Normal note deletion.
+        data.object_handler
+            .on_delete(&object_url, &actor_url)
+            .await
+            .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+        tracing::info!(object = %object_url, "received Delete(note)");
+        Ok(())
+    }
+}
+
+// --- Update ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct UpdateActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: UpdateType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: serde_json::Value,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub(crate) to: Vec<String>,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub(crate) cc: Vec<String>,
+}
+
+#[async_trait::async_trait]
+impl Activity for UpdateActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        if let Some(attributed_to) = self.object.get("attributedTo").and_then(|v| v.as_str())
+            && let Ok(attributed_url) = Url::parse(attributed_to)
+            && &attributed_url != self.actor.inner()
+        {
+            return Err(Error::bad_request(anyhow::anyhow!(
+                "Update actor does not match object attributedTo"
+            )));
+        }
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let domain = self.actor().host_str().unwrap_or("");
+        if data.federation_repo.is_domain_blocked(domain).await? {
+            tracing::info!(actor = %self.actor(), "ignoring activity from blocked domain");
+            return Ok(());
+        }
+        let ap_id = self
+            .object
+            .get("id")
+            .and_then(|v| v.as_str())
+            .and_then(|s| Url::parse(s).ok())
+            .unwrap_or_else(|| self.id.clone());
+        let actor_url = self.actor.inner().clone();
+        data.object_handler
+            .on_update(&ap_id, &actor_url, self.object)
+            .await
+            .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+        tracing::info!(actor = %actor_url, "received update activity");
+        Ok(())
+    }
+}
+
+// --- Announce ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct AnnounceActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: AnnounceType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: Url,
+    pub(crate) published: Option<chrono::DateTime<chrono::Utc>>,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub(crate) to: Vec<String>,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub(crate) cc: Vec<String>,
+}
+
+#[async_trait::async_trait]
+impl Activity for AnnounceActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let domain = self.actor().host_str().unwrap_or("");
+        if data.federation_repo.is_domain_blocked(domain).await? {
+            tracing::info!(actor = %self.actor(), "ignoring activity from blocked domain");
+            return Ok(());
+        }
+        let object_domain = self.object.host_str().unwrap_or("");
+        if object_domain != data.domain {
+            tracing::debug!(
+                actor = %self.actor.inner(),
+                object = %self.object,
+                "received Announce of non-local object — skipped (cross-server boost not supported)"
+            );
+            return Ok(());
+        }
+        data.federation_repo
+            .add_announce(
+                self.id.as_str(),
+                self.object.as_str(),
+                self.actor.inner().as_str(),
+                self.published.unwrap_or_else(chrono::Utc::now),
+            )
+            .await?;
+        data.object_handler
+            .on_announce_received(&self.object, self.actor.inner())
+            .await
+            .unwrap_or_else(|e| {
+                tracing::warn!(error = %e, "failed to process announce notification");
+            });
+        tracing::info!(actor = %self.actor.inner(), object = %self.object, "received announce");
+        Ok(())
+    }
+}
+
+// --- Like ---
+
+#[derive(Clone, Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct LikeActivity {
+    pub id: Url,
+    #[serde(rename = "type")]
+    pub kind: LikeType,
+    pub actor: ObjectId<DbActor>,
+    pub object: Url,
+}
+
+#[async_trait::async_trait]
+impl Activity for LikeActivity {
+    type DataType = FederationData;
+    type Error = crate::error::Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let domain = self.actor().host_str().unwrap_or("");
+        if data.federation_repo.is_domain_blocked(domain).await? {
+            tracing::info!(actor = %self.actor(), "ignoring Like from blocked domain");
+            return Ok(());
+        }
+
+        // Only process if the liked object is on our instance.
+        if self.object.host_str().unwrap_or("") != data.domain {
+            return Ok(());
+        }
+
+        data.object_handler
+            .on_like(&self.object, self.actor.inner())
+            .await
+            .map_err(|e| crate::error::Error::from(anyhow::anyhow!(e)))?;
+
+        tracing::info!(actor = %self.actor.inner(), object = %self.object, "received like");
+        Ok(())
+    }
+}
+
+// --- Add ---
+
+#[derive(Clone, Default, Debug, Serialize, Deserialize)]
+#[serde(rename = "Add")]
+pub struct AddType;
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct AddActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: AddType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: serde_json::Value,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub(crate) to: Vec<String>,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub(crate) cc: Vec<String>,
+}
+
+#[async_trait::async_trait]
+impl Activity for AddActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let domain = self.actor().host_str().unwrap_or("");
+        if data.federation_repo.is_domain_blocked(domain).await? {
+            tracing::info!(actor = %self.actor(), "ignoring Add from blocked domain");
+            return Ok(());
+        }
+        let ap_id = self.id.clone();
+        let actor_url = self.actor.inner().clone();
+        data.object_handler
+            .on_create(&ap_id, &actor_url, self.object)
+            .await
+            .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+        tracing::info!(actor = %actor_url, "received Add activity");
+        Ok(())
+    }
+}
+
+// --- Block ---
+
+#[derive(Clone, Default, Debug, Serialize, Deserialize)]
+#[serde(rename = "Block")]
+pub struct BlockType;
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct BlockActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: BlockType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: Url,
+}
+
+#[async_trait::async_trait]
+impl Activity for BlockActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let domain = self.actor().host_str().unwrap_or("");
+        if data.federation_repo.is_domain_blocked(domain).await? {
+            tracing::info!(actor = %self.actor(), "ignoring activity from blocked domain");
+            return Ok(());
+        }
+        if let Some(local_user_id) = crate::urls::extract_user_id_from_url(&self.object) {
+            let _ = data
+                .federation_repo
+                .remove_following(local_user_id, self.actor.inner().as_str())
+                .await;
+            let _ = data
+                .federation_repo
+                .remove_follower(local_user_id, self.actor.inner().as_str())
+                .await;
+        }
+        tracing::info!(actor = %self.actor.inner(), "received block — removed following and follower");
+        Ok(())
+    }
+}
+
+// --- Move (account migration) ---
+
+#[derive(Clone, Default, Debug, Serialize, Deserialize)]
+#[serde(rename = "Move")]
+pub struct MoveType;
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct MoveActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: MoveType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: Url,
+    pub(crate) target: Url,
+}
+
+#[async_trait::async_trait]
+impl Activity for MoveActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        if &self.object != self.actor.inner() {
+            return Err(Error::bad_request(anyhow::anyhow!(
+                "Move object must be the actor itself"
+            )));
+        }
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let domain = self.actor().host_str().unwrap_or("");
+        if data.federation_repo.is_domain_blocked(domain).await? {
+            return Ok(());
+        }
+        tracing::info!(
+            actor = %self.actor.inner(),
+            target = %self.target,
+            "received Move (account migration) — target noted"
+        );
+        Ok(())
+    }
+}
+
+// --- Inbox dispatch enum ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(tag = "type")]
+#[enum_delegate::implement(Activity)]
+pub enum InboxActivities {
+    #[serde(rename = "Follow")]
+    Follow(FollowActivity),
+    #[serde(rename = "Accept")]
+    Accept(AcceptActivity),
+    #[serde(rename = "Reject")]
+    Reject(RejectActivity),
+    #[serde(rename = "Undo")]
+    Undo(UndoActivity),
+    #[serde(rename = "Create")]
+    Create(CreateActivity),
+    #[serde(rename = "Delete")]
+    Delete(DeleteActivity),
+    #[serde(rename = "Update")]
+    Update(UpdateActivity),
+    #[serde(rename = "Announce")]
+    Announce(AnnounceActivity),
+    #[serde(rename = "Add")]
+    Add(AddActivity),
+    #[serde(rename = "Block")]
+    Block(BlockActivity),
+    #[serde(rename = "Like")]
+    Like(LikeActivity),
+    #[serde(rename = "Move")]
+    Move(MoveActivity),
+}

crates/adapters/activitypub-base/src/actor_handler.rs

@@ -0,0 +1,25 @@
+use activitypub_federation::{
+    axum::json::FederationJson, config::Data, protocol::context::WithContext, traits::Object,
+};
+use axum::extract::Path;
+
+use crate::actors::{Person, get_local_actor};
+use crate::data::FederationData;
+use crate::error::Error;
+
+pub async fn actor_handler(
+    Path(username): Path<String>,
+    data: Data<FederationData>,
+) -> Result<FederationJson<WithContext<Person>>, Error> {
+    let ap_user = data
+        .user_repo
+        .find_by_username(&username)
+        .await
+        .map_err(Error::from)?
+        .ok_or_else(|| Error::bad_request(anyhow::anyhow!("user not found")))?;
+
+    let db_actor = get_local_actor(ap_user.id, &data).await?;
+    let person = db_actor.into_json(&data).await?;
+
+    Ok(FederationJson(WithContext::new_default(person)))
+}

crates/adapters/activitypub-base/src/actors.rs

@@ -0,0 +1,372 @@
+use activitypub_federation::{
+    config::Data,
+    fetch::object_id::ObjectId,
+    http_signatures::generate_actor_keypair,
+    kinds::actor::PersonType,
+    protocol::{public_key::PublicKey, verification::verify_domains_match},
+    traits::{Actor, Object},
+};
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+use url::Url;
+
+use crate::data::FederationData;
+use crate::error::Error;
+use crate::repository::RemoteActor;
+use crate::user::ApProfileField;
+
+#[derive(Debug, Clone)]
+pub struct DbActor {
+    pub user_id: uuid::Uuid,
+    pub username: String,
+    pub public_key_pem: String,
+    pub private_key_pem: Option<String>,
+    pub inbox_url: Url,
+    pub shared_inbox_url: Option<Url>,
+    pub outbox_url: Url,
+    pub followers_url: Url,
+    pub following_url: Url,
+    pub ap_id: Url,
+    pub last_refreshed_at: DateTime<Utc>,
+    pub bio: Option<String>,
+    pub avatar_url: Option<Url>,
+    pub banner_url: Option<Url>,
+    pub also_known_as: Option<String>,
+    pub profile_url: Option<Url>,
+    pub attachment: Vec<ApProfileField>,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+pub struct ApImageObject {
+    #[serde(rename = "type")]
+    pub kind: String,
+    pub url: Url,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Endpoints {
+    pub shared_inbox: Url,
+}
+
+#[derive(Debug, Clone, Serialize, Deserialize)]
+pub struct ProfileFieldObject {
+    #[serde(rename = "type")]
+    pub kind: String,
+    pub name: String,
+    pub value: String,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Person {
+    #[serde(rename = "type")]
+    kind: PersonType,
+    id: ObjectId<DbActor>,
+    preferred_username: String,
+    inbox: Url,
+    outbox: Url,
+    followers: Url,
+    following: Url,
+    public_key: PublicKey,
+    name: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    summary: Option<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    icon: Option<ApImageObject>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    url: Option<Url>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    discoverable: Option<bool>,
+    manually_approves_followers: bool,
+    #[serde(skip_serializing_if = "Option::is_none", default)]
+    updated: Option<DateTime<Utc>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    endpoints: Option<Endpoints>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    image: Option<ApImageObject>,
+    #[serde(rename = "alsoKnownAs", skip_serializing_if = "Vec::is_empty", default)]
+    also_known_as: Vec<String>,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    attachment: Vec<ProfileFieldObject>,
+}
+
+struct ActorUrls {
+    ap_id: Url,
+    inbox_url: Url,
+    shared_inbox_url: Option<Url>,
+    outbox_url: Url,
+    followers_url: Url,
+    following_url: Url,
+}
+
+impl ActorUrls {
+    fn build(base_url: &str, user_id: uuid::Uuid) -> Self {
+        let ap_id = crate::urls::actor_url(base_url, user_id);
+        Self {
+            inbox_url: Url::parse(&format!("{}/inbox", &ap_id)).expect("valid url"),
+            shared_inbox_url: Url::parse(&format!("{}/inbox", base_url)).ok(),
+            outbox_url: Url::parse(&format!("{}/outbox", &ap_id)).expect("valid url"),
+            followers_url: Url::parse(&format!("{}/followers", &ap_id)).expect("valid url"),
+            following_url: Url::parse(&format!("{}/following", &ap_id)).expect("valid url"),
+            ap_id,
+        }
+    }
+}
+
+pub async fn get_local_actor(
+    user_id: uuid::Uuid,
+    data: &Data<FederationData>,
+) -> Result<DbActor, Error> {
+    let user = data
+        .user_repo
+        .find_by_id(user_id)
+        .await
+        .map_err(Error::from)?
+        .ok_or_else(|| Error::not_found(anyhow::anyhow!("user not found: {}", user_id)))?;
+
+    let (public_key, private_key) = match data
+        .federation_repo
+        .get_local_actor_keypair(user_id)
+        .await?
+    {
+        Some(kp) => kp,
+        None => {
+            let kp = generate_actor_keypair()?;
+            data.federation_repo
+                .save_local_actor_keypair(user_id, kp.public_key.clone(), kp.private_key.clone())
+                .await?;
+            (kp.public_key, kp.private_key)
+        }
+    };
+
+    let ActorUrls {
+        ap_id,
+        inbox_url,
+        shared_inbox_url,
+        outbox_url,
+        followers_url,
+        following_url,
+    } = ActorUrls::build(&data.base_url, user_id);
+
+    Ok(DbActor {
+        user_id,
+        username: user.username,
+        public_key_pem: public_key,
+        private_key_pem: Some(private_key),
+        inbox_url,
+        shared_inbox_url,
+        outbox_url,
+        followers_url,
+        following_url,
+        ap_id,
+        last_refreshed_at: Utc::now(),
+        bio: user.bio,
+        avatar_url: user.avatar_url,
+        banner_url: user.banner_url,
+        also_known_as: user.also_known_as,
+        profile_url: user.profile_url,
+        attachment: user.attachment,
+    })
+}
+
+#[async_trait::async_trait]
+impl Object for DbActor {
+    type DataType = FederationData;
+    type Kind = Person;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.ap_id
+    }
+
+    fn last_refreshed_at(&self) -> Option<DateTime<Utc>> {
+        Some(self.last_refreshed_at)
+    }
+
+    async fn read_from_id(
+        object_id: Url,
+        data: &Data<Self::DataType>,
+    ) -> Result<Option<Self>, Self::Error> {
+        let user_id = match crate::urls::extract_user_id_from_url(&object_id) {
+            Some(id) => id,
+            None => return Ok(None),
+        };
+        let user = match data.user_repo.find_by_id(user_id).await {
+            Ok(Some(u)) => u,
+            _ => return Ok(None),
+        };
+
+        let keypair = data
+            .federation_repo
+            .get_local_actor_keypair(user_id)
+            .await?;
+
+        let (public_key, private_key) = match keypair {
+            Some(kp) => (kp.0, Some(kp.1)),
+            None => return Ok(None),
+        };
+
+        let ActorUrls {
+            ap_id,
+            inbox_url,
+            shared_inbox_url,
+            outbox_url,
+            followers_url,
+            following_url,
+        } = ActorUrls::build(&data.base_url, user_id);
+
+        Ok(Some(DbActor {
+            user_id,
+            username: user.username,
+            public_key_pem: public_key,
+            private_key_pem: private_key,
+            inbox_url,
+            shared_inbox_url,
+            outbox_url,
+            followers_url,
+            following_url,
+            ap_id,
+            last_refreshed_at: Utc::now(),
+            bio: None,
+            avatar_url: None,
+            banner_url: None,
+            also_known_as: None,
+            profile_url: None,
+            attachment: vec![],
+        }))
+    }
+
+    async fn into_json(self, data: &Data<Self::DataType>) -> Result<Self::Kind, Self::Error> {
+        let public_key = PublicKey {
+            id: format!("{}#main-key", &self.ap_id),
+            owner: self.ap_id.clone(),
+            public_key_pem: self.public_key_pem.clone(),
+        };
+
+        let icon = self.avatar_url.map(|url| ApImageObject {
+            kind: "Image".to_string(),
+            url,
+        });
+        let image = self.banner_url.map(|url| ApImageObject {
+            kind: "Image".to_string(),
+            url,
+        });
+        let profile_url = self.profile_url;
+        let also_known_as: Vec<String> = self.also_known_as.into_iter().collect();
+        let attachment: Vec<ProfileFieldObject> = self
+            .attachment
+            .into_iter()
+            .map(|f| ProfileFieldObject {
+                kind: "PropertyValue".to_string(),
+                name: f.name,
+                value: f.value,
+            })
+            .collect();
+
+        let shared_inbox =
+            Url::parse(&format!("{}/inbox", data.base_url)).expect("base_url is always valid");
+
+        Ok(Person {
+            kind: Default::default(),
+            id: self.ap_id.clone().into(),
+            preferred_username: self.username.clone(),
+            inbox: self.inbox_url.clone(),
+            outbox: self.outbox_url.clone(),
+            followers: self.followers_url.clone(),
+            following: self.following_url.clone(),
+            public_key,
+            name: Some(self.username.clone()),
+            summary: self.bio.clone(),
+            icon,
+            url: profile_url,
+            discoverable: Some(true),
+            manually_approves_followers: true,
+            updated: Some(self.last_refreshed_at),
+            endpoints: Some(Endpoints { shared_inbox }),
+            image,
+            also_known_as,
+            attachment,
+        })
+    }
+
+    async fn verify(
+        json: &Self::Kind,
+        expected_domain: &Url,
+        _data: &Data<Self::DataType>,
+    ) -> Result<(), Self::Error> {
+        verify_domains_match(json.id.inner(), expected_domain)?;
+        Ok(())
+    }
+
+    async fn from_json(json: Self::Kind, data: &Data<Self::DataType>) -> Result<Self, Self::Error> {
+        let shared_inbox_url = json.endpoints.as_ref().map(|e| e.shared_inbox.to_string());
+        let actor = RemoteActor {
+            url: json.id.inner().to_string(),
+            handle: json.preferred_username.clone(),
+            inbox_url: json.inbox.to_string(),
+            shared_inbox_url,
+            display_name: json.name.clone(),
+            avatar_url: json.icon.as_ref().map(|i| i.url.to_string()),
+            outbox_url: Some(json.outbox.to_string()),
+        };
+        data.federation_repo.upsert_remote_actor(actor).await?;
+
+        let url_str = json.id.inner().to_string();
+        let user_id = uuid::Uuid::new_v5(&uuid::Uuid::NAMESPACE_URL, url_str.as_bytes());
+        let ap_id = json.id.inner().clone();
+        let inbox_url = json.inbox.clone();
+        let shared_inbox_url = json
+            .endpoints
+            .as_ref()
+            .and_then(|e| Url::parse(e.shared_inbox.as_str()).ok());
+        let outbox_url = json.outbox.clone();
+        let followers_url = json.followers.clone();
+        let following_url = json.following.clone();
+
+        Ok(DbActor {
+            user_id,
+            username: json.preferred_username.clone(),
+            public_key_pem: json.public_key.public_key_pem,
+            private_key_pem: None,
+            inbox_url,
+            shared_inbox_url,
+            outbox_url,
+            followers_url,
+            following_url,
+            ap_id,
+            last_refreshed_at: Utc::now(),
+            bio: json.summary.clone(),
+            avatar_url: json.icon.as_ref().map(|i| i.url.clone()),
+            banner_url: json.image.as_ref().map(|i| i.url.clone()),
+            also_known_as: json.also_known_as.into_iter().next(),
+            profile_url: json.url.clone(),
+            attachment: json
+                .attachment
+                .iter()
+                .map(|f| crate::user::ApProfileField {
+                    name: f.name.clone(),
+                    value: f.value.clone(),
+                })
+                .collect(),
+        })
+    }
+}
+
+impl Actor for DbActor {
+    fn public_key_pem(&self) -> &str {
+        &self.public_key_pem
+    }
+
+    fn private_key_pem(&self) -> Option<String> {
+        self.private_key_pem.clone()
+    }
+
+    fn inbox(&self) -> Url {
+        self.inbox_url.clone()
+    }
+}
+
+#[cfg(test)]
+#[path = "tests/actors.rs"]
+mod tests;

crates/adapters/activitypub-base/src/ap_ports.rs

@@ -0,0 +1,167 @@
+use async_trait::async_trait;
+use domain::{
+    errors::DomainError,
+    models::thought::Thought,
+    value_objects::{ThoughtId, UserId, Username},
+};
+
+/// AP-protocol endpoints for a locally-stored user (local or interned remote).
+#[derive(Debug, Clone)]
+pub struct ActorApUrls {
+    pub ap_id: String,
+    pub inbox_url: String,
+}
+
+/// A local thought ready for AP serialization, with the author's username
+/// pre-joined so the handler can build AP URLs without a second query.
+#[derive(Debug, Clone)]
+pub struct OutboxEntry {
+    pub thought: Thought,
+    pub author_username: Username,
+}
+
+#[async_trait]
+pub trait ActivityPubRepository: Send + Sync {
+    // ── Outbox (local → remote) ──────────────────────────────────────
+
+    /// All public local thoughts for this actor. Used for outbox totals
+    /// and full-collection delivery.
+    async fn outbox_entries_for_actor(
+        &self,
+        user_id: &UserId,
+    ) -> Result<Vec<OutboxEntry>, DomainError>;
+
+    /// Cursor page of public local thoughts, newest-first, before `before`.
+    /// Used for OrderedCollectionPage responses.
+    async fn outbox_page_for_actor(
+        &self,
+        user_id: &UserId,
+        before: Option<chrono::DateTime<chrono::Utc>>,
+        limit: usize,
+    ) -> Result<Vec<OutboxEntry>, DomainError>;
+
+    // ── Remote actor resolution ──────────────────────────────────────
+
+    /// Find the local UserId for a remote actor by its AP URL.
+    async fn find_remote_actor_id(&self, actor_ap_url: &str)
+        -> Result<Option<UserId>, DomainError>;
+
+    /// Ensure a remote actor placeholder exists; create one if absent.
+    /// Idempotent — safe to call multiple times with the same URL.
+    async fn intern_remote_actor(&self, actor_ap_url: &str) -> Result<UserId, DomainError>;
+
+    /// Update display_name and avatar_url for an already-interned remote actor.
+    async fn update_remote_actor_display(
+        &self,
+        user_id: &UserId,
+        display_name: Option<&str>,
+        avatar_url: Option<&str>,
+    ) -> Result<(), DomainError>;
+
+    // ── Inbox processing (remote → local) ───────────────────────────
+
+    /// Persist an incoming remote Note. Idempotent on ap_id.
+    #[allow(clippy::too_many_arguments)]
+    async fn accept_note(
+        &self,
+        ap_id: &str,
+        author_id: &UserId,
+        content: &str,
+        published: chrono::DateTime<chrono::Utc>,
+        sensitive: bool,
+        content_warning: Option<String>,
+        visibility: &str,
+        in_reply_to: Option<&str>,
+    ) -> Result<ThoughtId, DomainError>;
+
+    /// Apply an Update to a previously accepted remote Note.
+    async fn apply_note_update(&self, ap_id: &str, new_content: &str) -> Result<(), DomainError>;
+
+    /// Remove a specific remote Note (Delete activity). Only touches
+    /// remotely-originated thoughts.
+    async fn retract_note(&self, ap_id: &str) -> Result<(), DomainError>;
+
+    /// Remove all Notes from a remote actor (actor-level Delete/Tombstone).
+    async fn retract_actor_notes(&self, actor_ap_url: &str) -> Result<(), DomainError>;
+
+    // ── Node-level stats ─────────────────────────────────────────────
+
+    /// Total locally-authored thought count for NodeInfo responses.
+    async fn count_local_notes(&self) -> Result<u64, DomainError>;
+
+    /// Return the ActivityPub object URL for a thought, if one is stored.
+    /// Returns None for local thoughts (caller constructs URL from base_url + thought_id).
+    async fn get_thought_ap_id(
+        &self,
+        thought_id: &ThoughtId,
+    ) -> Result<Option<String>, DomainError>;
+
+    /// Return the AP actor URL and inbox URL for a user, if stored.
+    /// Returns None for users that have not been federated.
+    async fn get_actor_ap_urls(&self, user_id: &UserId)
+        -> Result<Option<ActorApUrls>, DomainError>;
+}
+
+#[async_trait]
+pub trait OutboundFederationPort: Send + Sync {
+    /// Fan out a new local Note to all accepted followers.
+    async fn broadcast_create(
+        &self,
+        author_user_id: &UserId,
+        thought: &Thought,
+        author_username: &str,
+        in_reply_to_url: Option<&str>,
+    ) -> Result<(), DomainError>;
+
+    /// Fan out a Delete tombstone for a now-deleted local Note.
+    /// `thought_ap_id` is pre-constructed by the caller because the thought
+    /// has already been deleted from the DB when this fires.
+    async fn broadcast_delete(
+        &self,
+        author_user_id: &UserId,
+        thought_ap_id: &str,
+    ) -> Result<(), DomainError>;
+
+    /// Fan out an Update(Note) for an edited local thought.
+    async fn broadcast_update(
+        &self,
+        author_user_id: &UserId,
+        thought: &Thought,
+        author_username: &str,
+        in_reply_to_url: Option<&str>,
+    ) -> Result<(), DomainError>;
+
+    /// Fan out an Announce(object_ap_id) for a boost.
+    async fn broadcast_announce(
+        &self,
+        booster_user_id: &UserId,
+        object_ap_id: &str,
+    ) -> Result<(), DomainError>;
+
+    /// Fan out an Undo(Announce) to followers when a boost is removed.
+    async fn broadcast_undo_announce(
+        &self,
+        booster_user_id: &UserId,
+        object_ap_id: &str,
+    ) -> Result<(), DomainError>;
+
+    /// Send a Like activity to a remote thought author's inbox.
+    /// Only called when a LOCAL user likes a REMOTE thought (one with an ap_id).
+    async fn broadcast_like(
+        &self,
+        liker_user_id: &UserId,
+        object_ap_id: &str,
+        author_inbox_url: &str,
+    ) -> Result<(), DomainError>;
+
+    /// Send Undo(Like) to a remote thought author's inbox.
+    async fn broadcast_undo_like(
+        &self,
+        liker_user_id: &UserId,
+        object_ap_id: &str,
+        author_inbox_url: &str,
+    ) -> Result<(), DomainError>;
+
+    /// Fan out an Update(Actor) to all accepted followers after a profile change.
+    async fn broadcast_actor_update(&self, user_id: &UserId) -> Result<(), DomainError>;
+}

crates/adapters/activitypub-base/src/content.rs

@@ -0,0 +1,68 @@
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+use url::Url;
+
+#[async_trait]
+pub trait ApObjectHandler: Send + Sync {
+    /// Returns (ap_id, serialized object) for all local content owned by this user.
+    /// Used by outbox (count) and backfill (delivery). Must only return locally-authored content.
+    async fn get_local_objects_for_user(
+        &self,
+        user_id: uuid::Uuid,
+    ) -> anyhow::Result<Vec<(Url, serde_json::Value)>>;
+
+    /// Returns up to `limit` objects ordered newest-first, published before `before`.
+    /// Returns (ap_id, object_json, published_at).
+    async fn get_local_objects_page(
+        &self,
+        user_id: uuid::Uuid,
+        before: Option<DateTime<Utc>>,
+        limit: usize,
+    ) -> anyhow::Result<Vec<(Url, serde_json::Value, DateTime<Utc>)>>;
+
+    /// Incoming Create activity — persist remote content.
+    async fn on_create(
+        &self,
+        ap_id: &Url,
+        actor_url: &Url,
+        object: serde_json::Value,
+    ) -> anyhow::Result<()>;
+
+    /// Incoming Update activity — update existing remote content.
+    async fn on_update(
+        &self,
+        ap_id: &Url,
+        actor_url: &Url,
+        object: serde_json::Value,
+    ) -> anyhow::Result<()>;
+
+    /// Incoming Delete activity — remove specific remote content.
+    async fn on_delete(&self, ap_id: &Url, actor_url: &Url) -> anyhow::Result<()>;
+
+    /// Actor unfollowed/was removed — clean up all their remote content.
+    async fn on_actor_removed(&self, actor_url: &Url) -> anyhow::Result<()>;
+
+    /// Called when a remote actor likes a local thought.
+    /// `object_url` is the AP URL of the liked note (e.g. `{base}/thoughts/{uuid}`).
+    /// `actor_url` is the AP URL of the remote actor who sent the Like.
+    async fn on_like(&self, object_url: &Url, actor_url: &Url) -> anyhow::Result<()>;
+
+    /// Called when a remote actor boosts (Announce) a local thought.
+    /// `object_url` is the AP URL of the announced note.
+    /// `actor_url` is the AP URL of the remote actor who sent the Announce.
+    async fn on_announce_received(&self, object_url: &Url, actor_url: &Url) -> anyhow::Result<()>;
+
+    /// Called when a remote actor removes a Like from a local thought.
+    async fn on_unlike(&self, object_url: &Url, actor_url: &Url) -> anyhow::Result<()>;
+
+    /// Called when an inbound Note tags a local user with a Mention.
+    async fn on_mention(
+        &self,
+        thought_ap_id: &Url,
+        mentioned_user_uuid: uuid::Uuid,
+        actor_url: &Url,
+    ) -> anyhow::Result<()>;
+
+    /// Total number of locally-authored posts across all users.
+    async fn count_local_posts(&self) -> anyhow::Result<u64>;
+}

crates/adapters/activitypub-base/src/data.rs

@@ -0,0 +1,49 @@
+use std::sync::Arc;
+
+use crate::content::ApObjectHandler;
+use crate::repository::FederationRepository;
+use crate::user::ApUserRepository;
+use domain::ports::EventPublisher;
+
+#[derive(Clone)]
+pub struct FederationData {
+    pub(crate) federation_repo: Arc<dyn FederationRepository>,
+    pub(crate) user_repo: Arc<dyn ApUserRepository>,
+    pub(crate) object_handler: Arc<dyn ApObjectHandler>,
+    pub(crate) base_url: String,
+    pub(crate) domain: String,
+    pub(crate) allow_registration: bool,
+    pub(crate) software_name: String,
+    #[allow(dead_code)]
+    pub(crate) event_publisher: Option<Arc<dyn EventPublisher>>,
+}
+
+impl FederationData {
+    pub fn new(
+        federation_repo: Arc<dyn FederationRepository>,
+        user_repo: Arc<dyn ApUserRepository>,
+        object_handler: Arc<dyn ApObjectHandler>,
+        base_url: String,
+        allow_registration: bool,
+        software_name: String,
+        event_publisher: Option<Arc<dyn EventPublisher>>,
+    ) -> Self {
+        let domain = base_url
+            .trim_start_matches("https://")
+            .trim_start_matches("http://")
+            .split('/')
+            .next()
+            .unwrap_or("")
+            .to_string();
+        Self {
+            federation_repo,
+            user_repo,
+            object_handler,
+            base_url,
+            domain,
+            allow_registration,
+            software_name,
+            event_publisher,
+        }
+    }
+}

crates/adapters/activitypub-base/src/error.rs

@@ -0,0 +1,48 @@
+use std::fmt::{Display, Formatter};
+
+use axum::http::StatusCode;
+
+#[derive(Debug)]
+pub struct Error(pub(crate) anyhow::Error, pub(crate) StatusCode);
+
+impl Error {
+    pub fn not_found(e: impl Into<anyhow::Error>) -> Self {
+        Self(e.into(), StatusCode::NOT_FOUND)
+    }
+
+    pub fn bad_request(e: impl Into<anyhow::Error>) -> Self {
+        Self(e.into(), StatusCode::BAD_REQUEST)
+    }
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        std::fmt::Display::fmt(&self.0, f)
+    }
+}
+
+impl<T> From<T> for Error
+where
+    T: Into<anyhow::Error>,
+{
+    fn from(t: T) -> Self {
+        Error(t.into(), StatusCode::INTERNAL_SERVER_ERROR)
+    }
+}
+
+impl axum::response::IntoResponse for Error {
+    fn into_response(self) -> axum::response::Response {
+        let status = self.1;
+        if status.is_server_error() {
+            tracing::error!(error = %self.0, status = status.as_u16(), "federation error");
+        } else {
+            tracing::debug!(error = %self.0, status = status.as_u16(), "federation response");
+        }
+        let body = if status.is_server_error() {
+            "internal server error".to_string()
+        } else {
+            self.0.to_string()
+        };
+        (status, body).into_response()
+    }
+}

crates/adapters/activitypub-base/src/federation.rs

@@ -0,0 +1,49 @@
+use activitypub_federation::config::{Data, FederationConfig, FederationMiddleware, UrlVerifier};
+use activitypub_federation::error::Error as FedError;
+use url::Url;
+
+use crate::data::FederationData;
+
+#[derive(Clone)]
+struct PermissiveVerifier;
+
+#[async_trait::async_trait]
+impl UrlVerifier for PermissiveVerifier {
+    async fn verify(&self, _url: &Url) -> Result<(), FedError> {
+        Ok(())
+    }
+}
+
+#[derive(Clone)]
+pub struct ApFederationConfig(pub FederationConfig<FederationData>);
+
+impl ApFederationConfig {
+    pub async fn new(data: FederationData, debug: bool) -> anyhow::Result<Self> {
+        let config = if debug {
+            FederationConfig::builder()
+                .domain(&data.domain)
+                .app_data(data)
+                .debug(true)
+                .http_signature_compat(true)
+                .url_verifier(Box::new(PermissiveVerifier))
+                .build()
+                .await?
+        } else {
+            FederationConfig::builder()
+                .domain(&data.domain)
+                .app_data(data)
+                .debug(false)
+                .build()
+                .await?
+        };
+        Ok(Self(config))
+    }
+
+    pub fn to_request_data(&self) -> Data<FederationData> {
+        self.0.to_request_data()
+    }
+
+    pub fn middleware(&self) -> FederationMiddleware<FederationData> {
+        FederationMiddleware::new(self.0.clone())
+    }
+}

crates/adapters/activitypub-base/src/followers_handler.rs

@@ -0,0 +1,105 @@
+use activitypub_federation::{axum::json::FederationJson, config::Data};
+use axum::extract::{Path, Query};
+use serde::Deserialize;
+use serde_json::json;
+
+use crate::data::FederationData;
+use crate::error::Error;
+use crate::urls::AP_PAGE_SIZE;
+
+#[derive(Deserialize)]
+pub struct PageQuery {
+    page: Option<u32>,
+}
+
+async fn collection_handler(
+    user_id_str: &str,
+    query: PageQuery,
+    data: Data<FederationData>,
+    collection_type: &str,
+) -> Result<FederationJson<serde_json::Value>, Error> {
+    let user_id = uuid::Uuid::parse_str(user_id_str)
+        .map_err(|_| Error::bad_request(anyhow::anyhow!("invalid user id")))?;
+
+    data.user_repo
+        .find_by_id(user_id)
+        .await
+        .map_err(Error::from)?
+        .ok_or_else(|| Error::not_found(anyhow::anyhow!("user not found")))?;
+
+    let collection_id = format!(
+        "{}/users/{}/{}",
+        data.base_url, user_id_str, collection_type
+    );
+
+    let total = match collection_type {
+        "followers" => data.federation_repo.count_followers(user_id).await,
+        _ => data.federation_repo.count_following(user_id).await,
+    }
+    .map_err(Error::from)?;
+
+    if let Some(page) = query.page {
+        let page = page.max(1);
+        let offset = (page.saturating_sub(1) as usize) * AP_PAGE_SIZE;
+
+        let items: Vec<String> = match collection_type {
+            "followers" => data
+                .federation_repo
+                .get_followers_page(user_id, offset as u32, AP_PAGE_SIZE)
+                .await
+                .map_err(Error::from)?
+                .into_iter()
+                .map(|f| f.actor.url)
+                .collect(),
+            _ => data
+                .federation_repo
+                .get_following_page(user_id, offset as u32, AP_PAGE_SIZE)
+                .await
+                .map_err(Error::from)?
+                .into_iter()
+                .map(|a| a.url)
+                .collect(),
+        };
+
+        let has_next = offset + items.len() < total;
+
+        let mut obj = json!({
+            "@context": crate::urls::AP_CONTEXT,
+            "type": "OrderedCollectionPage",
+            "id": format!("{}?page={}", collection_id, page),
+            "partOf": collection_id,
+            "totalItems": total,
+            "orderedItems": items,
+        });
+
+        if has_next {
+            obj["next"] = json!(format!("{}?page={}", collection_id, page + 1));
+        }
+
+        Ok(FederationJson(obj))
+    } else {
+        Ok(FederationJson(json!({
+            "@context": crate::urls::AP_CONTEXT,
+            "type": "OrderedCollection",
+            "id": collection_id,
+            "totalItems": total,
+            "first": format!("{}?page=1", collection_id),
+        })))
+    }
+}
+
+pub async fn followers_handler(
+    Path(user_id_str): Path<String>,
+    Query(query): Query<PageQuery>,
+    data: Data<FederationData>,
+) -> Result<FederationJson<serde_json::Value>, Error> {
+    collection_handler(&user_id_str, query, data, "followers").await
+}
+
+pub async fn following_handler(
+    Path(user_id_str): Path<String>,
+    Query(query): Query<PageQuery>,
+    data: Data<FederationData>,
+) -> Result<FederationJson<serde_json::Value>, Error> {
+    collection_handler(&user_id_str, query, data, "following").await
+}

crates/adapters/activitypub-base/src/inbox.rs

@@ -0,0 +1,18 @@
+use activitypub_federation::{
+    axum::inbox::{ActivityData, receive_activity},
+    config::Data,
+    protocol::context::WithContext,
+};
+
+use crate::activities::InboxActivities;
+use crate::actors::DbActor;
+use crate::data::FederationData;
+use crate::error::Error;
+
+pub async fn inbox_handler(
+    data: Data<FederationData>,
+    activity_data: ActivityData,
+) -> Result<(), Error> {
+    receive_activity::<WithContext<InboxActivities>, DbActor, FederationData>(activity_data, &data)
+        .await
+}

crates/adapters/activitypub-base/src/lib.rs

@@ -0,0 +1,30 @@
+pub mod activities;
+pub mod actor_handler;
+pub mod actors;
+pub mod ap_ports;
+pub mod content;
+pub mod data;
+pub mod error;
+pub mod federation;
+pub mod followers_handler;
+pub mod inbox;
+pub mod nodeinfo;
+pub mod outbox;
+pub mod repository;
+pub mod service;
+pub(crate) mod urls;
+pub use urls::AS_PUBLIC;
+pub mod user;
+pub mod webfinger;
+
+pub use activitypub_federation::kinds::object::NoteType;
+pub use ap_ports::{ActorApUrls, ActivityPubRepository, OutboxEntry, OutboundFederationPort};
+pub use content::ApObjectHandler;
+pub use data::FederationData;
+pub use error::Error;
+pub use federation::ApFederationConfig;
+pub use repository::{
+    BlockedDomain, FederationRepository, Follower, FollowerStatus, FollowingStatus, RemoteActor,
+};
+pub use service::ActivityPubService;
+pub use user::{ApProfileField, ApUser, ApUserRepository};

crates/adapters/activitypub-base/src/nodeinfo.rs

@@ -0,0 +1,82 @@
+use activitypub_federation::config::Data;
+use axum::Json;
+use serde::Serialize;
+
+use crate::data::FederationData;
+use crate::error::Error;
+
+const NODEINFO_2_0_REL: &str = "http://nodeinfo.diaspora.software/ns/schema/2.0";
+
+#[derive(Serialize)]
+pub struct NodeInfoWellKnown {
+    pub links: Vec<NodeInfoLink>,
+}
+
+#[derive(Serialize)]
+pub struct NodeInfoLink {
+    pub rel: String,
+    pub href: String,
+}
+
+#[derive(Serialize)]
+pub struct NodeInfoSoftware {
+    pub name: String,
+    pub version: String,
+}
+
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct NodeInfoUsage {
+    pub users: NodeInfoUsers,
+    pub local_posts: u64,
+}
+
+#[derive(Serialize)]
+pub struct NodeInfoUsers {
+    pub total: usize,
+}
+
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct NodeInfo {
+    pub version: String,
+    pub software: NodeInfoSoftware,
+    pub protocols: Vec<String>,
+    pub usage: NodeInfoUsage,
+    pub open_registrations: bool,
+}
+
+pub async fn nodeinfo_well_known_handler(
+    data: Data<FederationData>,
+) -> Result<Json<NodeInfoWellKnown>, Error> {
+    let href = format!("{}/nodeinfo/2.0", data.base_url);
+    Ok(Json(NodeInfoWellKnown {
+        links: vec![NodeInfoLink {
+            rel: NODEINFO_2_0_REL.to_string(),
+            href,
+        }],
+    }))
+}
+
+pub async fn nodeinfo_handler(data: Data<FederationData>) -> Result<Json<NodeInfo>, Error> {
+    let user_count = data.user_repo.count_users().await.unwrap_or(0);
+    let local_posts = data.object_handler.count_local_posts().await.unwrap_or(0);
+
+    Ok(Json(NodeInfo {
+        version: "2.0".to_string(),
+        software: NodeInfoSoftware {
+            name: data.software_name.clone(),
+            version: env!("CARGO_PKG_VERSION").to_string(),
+        },
+        protocols: vec!["activitypub".to_string()],
+        usage: NodeInfoUsage {
+            users: NodeInfoUsers { total: user_count },
+            local_posts,
+        },
+        open_registrations: data.allow_registration,
+    }))
+}
+
+#[cfg(test)]
+#[path = "tests/nodeinfo.rs"]
+mod tests;

crates/adapters/activitypub-base/src/outbox.rs

@@ -0,0 +1,138 @@
+use axum::extract::{Path, Query};
+use axum::response::IntoResponse;
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+use url::Url;
+
+use activitypub_federation::{
+    config::Data, fetch::object_id::ObjectId, kinds::activity::CreateType,
+    protocol::context::WithContext,
+};
+
+use crate::{activities::CreateActivity, data::FederationData, error::Error, urls::AP_PAGE_SIZE};
+
+#[derive(Deserialize)]
+pub struct OutboxQuery {
+    page: Option<bool>,
+    before: Option<String>,
+}
+
+#[derive(Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct OrderedCollection {
+    #[serde(rename = "@context")]
+    context: String,
+    #[serde(rename = "type")]
+    kind: String,
+    id: String,
+    total_items: u64,
+    first: String,
+}
+
+#[derive(Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct OrderedCollectionPage {
+    #[serde(rename = "@context")]
+    context: String,
+    #[serde(rename = "type")]
+    kind: String,
+    id: String,
+    part_of: String,
+    ordered_items: Vec<serde_json::Value>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    next: Option<String>,
+}
+
+pub async fn outbox_handler(
+    Path(user_id_str): Path<String>,
+    Query(query): Query<OutboxQuery>,
+    data: Data<FederationData>,
+) -> Result<axum::response::Response, Error> {
+    let uuid = uuid::Uuid::parse_str(&user_id_str)
+        .map_err(|_| Error::bad_request(anyhow::anyhow!("invalid user id")))?;
+
+    data.user_repo
+        .find_by_id(uuid)
+        .await
+        .map_err(Error::from)?
+        .ok_or_else(|| Error::not_found(anyhow::anyhow!("user not found")))?;
+
+    let outbox_url = format!("{}/users/{}/outbox", data.base_url, user_id_str);
+
+    if query.page.unwrap_or(false) {
+        let before: Option<DateTime<Utc>> = query.before.as_deref().and_then(|s| s.parse().ok());
+
+        let items = data
+            .object_handler
+            .get_local_objects_page(uuid, before, AP_PAGE_SIZE)
+            .await
+            .map_err(|e| Error::from(anyhow::anyhow!("{}", e)))?;
+
+        let actor_url: Url = format!("{}/users/{}", data.base_url, user_id_str)
+            .parse()
+            .expect("valid url");
+
+        let has_more = items.len() == AP_PAGE_SIZE;
+        let oldest_ts = items.last().map(|(_, _, ts)| *ts);
+
+        let followers_url = format!("{}/followers", actor_url);
+        let ordered_items: Vec<serde_json::Value> = items
+            .into_iter()
+            .map(|(ap_id, object, _)| {
+                let create_id = Url::parse(&format!("{}/activity", ap_id)).expect("valid url");
+                serde_json::to_value(WithContext::new_default(CreateActivity {
+                    id: create_id,
+                    kind: CreateType::default(),
+                    actor: ObjectId::from(actor_url.clone()),
+                    object,
+                    to: vec![crate::urls::AS_PUBLIC.to_string()],
+                    cc: vec![followers_url.clone()],
+                    bto: vec![],
+                    bcc: vec![],
+                }))
+                .expect("serializable")
+            })
+            .collect();
+
+        let page_id = match &query.before {
+            Some(b) => format!("{}?page=true&before={}", outbox_url, b),
+            None => format!("{}?page=true", outbox_url),
+        };
+
+        let next = if has_more {
+            oldest_ts.map(|ts| {
+                // Use RFC 3339 with Z suffix (no + sign) to avoid percent-encoding
+                let ts_str = ts.format("%Y-%m-%dT%H:%M:%S%.3fZ").to_string();
+                format!("{}?page=true&before={}", outbox_url, ts_str)
+            })
+        } else {
+            None
+        };
+
+        Ok(axum::Json(OrderedCollectionPage {
+            context: crate::urls::AP_CONTEXT.to_string(),
+            kind: "OrderedCollectionPage".to_string(),
+            id: page_id,
+            part_of: outbox_url,
+            ordered_items,
+            next,
+        })
+        .into_response())
+    } else {
+        let total = data
+            .object_handler
+            .get_local_objects_for_user(uuid)
+            .await
+            .map_err(|e| Error::from(anyhow::anyhow!("{}", e)))?
+            .len() as u64;
+
+        Ok(axum::Json(OrderedCollection {
+            context: crate::urls::AP_CONTEXT.to_string(),
+            kind: "OrderedCollection".to_string(),
+            id: outbox_url.clone(),
+            total_items: total,
+            first: format!("{}?page=true", outbox_url),
+        })
+        .into_response())
+    }
+}

crates/adapters/activitypub-base/src/repository.rs

@@ -0,0 +1,134 @@
+use anyhow::Result;
+use async_trait::async_trait;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum FollowerStatus {
+    Pending,
+    Accepted,
+    Rejected,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum FollowingStatus {
+    Pending,
+    Accepted,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct RemoteActor {
+    pub url: String,
+    pub handle: String,
+    pub inbox_url: String,
+    pub shared_inbox_url: Option<String>,
+    pub display_name: Option<String>,
+    pub avatar_url: Option<String>,
+    pub outbox_url: Option<String>,
+}
+
+#[derive(Debug, Clone)]
+pub struct Follower {
+    pub actor: RemoteActor,
+    pub status: FollowerStatus,
+}
+
+#[derive(Debug, Clone)]
+pub struct BlockedDomain {
+    pub domain: String,
+    pub reason: Option<String>,
+    pub blocked_at: String,
+}
+
+#[async_trait]
+pub trait FederationRepository: Send + Sync {
+    async fn add_follower(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+        status: FollowerStatus,
+        follow_activity_id: &str,
+    ) -> Result<()>;
+    async fn get_follower_follow_activity_id(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+    ) -> Result<Option<String>>;
+    async fn remove_follower(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+    ) -> Result<()>;
+    async fn get_followers(&self, local_user_id: uuid::Uuid) -> Result<Vec<Follower>>;
+    async fn get_followers_page(
+        &self,
+        local_user_id: uuid::Uuid,
+        offset: u32,
+        limit: usize,
+    ) -> Result<Vec<Follower>>;
+    async fn count_followers(&self, local_user_id: uuid::Uuid) -> Result<usize>;
+    async fn get_following_page(
+        &self,
+        local_user_id: uuid::Uuid,
+        offset: u32,
+        limit: usize,
+    ) -> Result<Vec<RemoteActor>>;
+    async fn update_follower_status(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+        status: FollowerStatus,
+    ) -> Result<()>;
+    async fn add_following(
+        &self,
+        local_user_id: uuid::Uuid,
+        actor: RemoteActor,
+        follow_activity_id: &str,
+    ) -> Result<()>;
+    async fn get_follow_activity_id(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+    ) -> Result<Option<String>>;
+    async fn remove_following(&self, local_user_id: uuid::Uuid, actor_url: &str) -> Result<()>;
+    async fn get_following(&self, local_user_id: uuid::Uuid) -> Result<Vec<RemoteActor>>;
+    async fn count_following(&self, local_user_id: uuid::Uuid) -> Result<usize>;
+    async fn upsert_remote_actor(&self, actor: RemoteActor) -> Result<()>;
+    async fn get_remote_actor(&self, actor_url: &str) -> Result<Option<RemoteActor>>;
+    async fn get_local_actor_keypair(
+        &self,
+        user_id: uuid::Uuid,
+    ) -> Result<Option<(String, String)>>;
+    async fn save_local_actor_keypair(
+        &self,
+        user_id: uuid::Uuid,
+        public_key: String,
+        private_key: String,
+    ) -> Result<()>;
+    async fn get_pending_followers(&self, local_user_id: uuid::Uuid) -> Result<Vec<RemoteActor>>;
+    async fn update_following_status(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+        status: FollowingStatus,
+    ) -> Result<()>;
+    async fn get_following_outbox_url(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+    ) -> Result<Option<String>>;
+    async fn add_announce(
+        &self,
+        activity_id: &str,
+        object_url: &str,
+        actor_url: &str,
+        announced_at: chrono::DateTime<chrono::Utc>,
+    ) -> Result<()>;
+    async fn count_announces(&self, object_url: &str) -> Result<usize>;
+    async fn add_blocked_domain(&self, domain: &str, reason: Option<&str>) -> Result<()>;
+    async fn remove_blocked_domain(&self, domain: &str) -> Result<()>;
+    async fn get_blocked_domains(&self) -> Result<Vec<BlockedDomain>>;
+    async fn is_domain_blocked(&self, domain: &str) -> Result<bool>;
+    async fn add_blocked_actor(&self, local_user_id: uuid::Uuid, actor_url: &str) -> Result<()>;
+    async fn remove_blocked_actor(&self, local_user_id: uuid::Uuid, actor_url: &str) -> Result<()>;
+    async fn get_blocked_actors(&self, local_user_id: uuid::Uuid) -> Result<Vec<String>>;
+    async fn is_actor_blocked(&self, local_user_id: uuid::Uuid, actor_url: &str) -> Result<bool>;
+}

crates/adapters/activitypub-base/src/tests/actors.rs

@@ -0,0 +1,49 @@
+use super::*;
+
+#[test]
+fn person_serializes_with_enriched_fields() {
+    let person = Person {
+        kind: Default::default(),
+        id: "https://example.com/users/1"
+            .parse::<url::Url>()
+            .unwrap()
+            .into(),
+        preferred_username: "alice".to_string(),
+        inbox: "https://example.com/users/1/inbox".parse().unwrap(),
+        outbox: "https://example.com/users/1/outbox".parse().unwrap(),
+        followers: "https://example.com/users/1/followers".parse().unwrap(),
+        following: "https://example.com/users/1/following".parse().unwrap(),
+        public_key: PublicKey {
+            id: "https://example.com/users/1#main-key".to_string(),
+            owner: "https://example.com/users/1".parse().unwrap(),
+            public_key_pem: "pem".to_string(),
+        },
+        name: Some("Alice".to_string()),
+        summary: Some("Bio text".to_string()),
+        icon: Some(ApImageObject {
+            kind: "Image".to_string(),
+            url: "https://example.com/images/avatars/1".parse().unwrap(),
+        }),
+        url: Some("https://example.com/u/alice".parse().unwrap()),
+        discoverable: Some(true),
+        manually_approves_followers: true,
+        updated: Some(Utc::now()),
+        endpoints: Some(Endpoints {
+            shared_inbox: "https://example.com/inbox".parse().unwrap(),
+        }),
+        image: None,
+        also_known_as: vec![],
+        attachment: vec![],
+    };
+    let json = serde_json::to_value(&person).unwrap();
+    assert_eq!(json["discoverable"], true);
+    assert_eq!(json["summary"], "Bio text");
+    assert_eq!(json["icon"]["type"], "Image");
+    assert_eq!(json["manuallyApprovesFollowers"], true);
+    assert!(json.get("updated").is_some());
+    assert!(json.get("endpoints").is_some());
+    assert_eq!(
+        json["endpoints"]["sharedInbox"],
+        "https://example.com/inbox"
+    );
+}

crates/adapters/activitypub-base/src/tests/nodeinfo.rs

@@ -0,0 +1,40 @@
+use super::*;
+
+#[test]
+fn nodeinfo_well_known_serializes_correctly() {
+    let doc = NodeInfoWellKnown {
+        links: vec![NodeInfoLink {
+            rel: "http://nodeinfo.diaspora.software/ns/schema/2.0".to_string(),
+            href: "https://example.com/nodeinfo/2.0".to_string(),
+        }],
+    };
+    let json = serde_json::to_value(&doc).unwrap();
+    assert_eq!(
+        json["links"][0]["rel"],
+        "http://nodeinfo.diaspora.software/ns/schema/2.0"
+    );
+    assert_eq!(json["links"][0]["href"], "https://example.com/nodeinfo/2.0");
+}
+
+#[test]
+fn nodeinfo_serializes_camel_case() {
+    let doc = NodeInfo {
+        version: "2.0".to_string(),
+        software: NodeInfoSoftware {
+            name: "my-app".to_string(),
+            version: "0.1.0".to_string(),
+        },
+        protocols: vec!["activitypub".to_string()],
+        usage: NodeInfoUsage {
+            users: NodeInfoUsers { total: 3 },
+            local_posts: 42,
+        },
+        open_registrations: false,
+    };
+    let json = serde_json::to_value(&doc).unwrap();
+    assert_eq!(json["version"], "2.0");
+    assert_eq!(json["software"]["name"], "my-app");
+    assert_eq!(json["usage"]["users"]["total"], 3);
+    assert_eq!(json["usage"]["localPosts"], 42);
+    assert_eq!(json["openRegistrations"], false);
+}

crates/adapters/activitypub-base/src/tests/service.rs

@@ -0,0 +1,75 @@
+fn _assert_impl_federation_lookup_port()
+where
+    crate::service::ActivityPubService: domain::ports::FederationLookupPort,
+{
+}
+
+fn _assert_impl_federation_follow_port()
+where
+    crate::service::ActivityPubService: domain::ports::FederationFollowPort,
+{
+}
+
+fn _assert_impl_federation_follow_request_port()
+where
+    crate::service::ActivityPubService: domain::ports::FederationFollowRequestPort,
+{
+}
+
+fn _assert_impl_federation_fetch_port()
+where
+    crate::service::ActivityPubService: domain::ports::FederationFetchPort,
+{
+}
+
+fn _assert_impl_federation_action_port()
+where
+    crate::service::ActivityPubService: domain::ports::FederationActionPort,
+{
+}
+
+use super::*;
+use crate::repository::{Follower, FollowerStatus, RemoteActor};
+
+fn make_follower(inbox: &str, shared: Option<&str>) -> Follower {
+    Follower {
+        actor: RemoteActor {
+            url: format!("https://remote/{}", inbox),
+            handle: "user".to_string(),
+            inbox_url: inbox.to_string(),
+            shared_inbox_url: shared.map(|s| s.to_string()),
+            display_name: None,
+            avatar_url: None,
+            outbox_url: None,
+        },
+        status: FollowerStatus::Accepted,
+    }
+}
+
+#[test]
+fn collect_inboxes_deduplicates_shared() {
+    let followers = vec![
+        make_follower(
+            "https://mastodon.social/users/a/inbox",
+            Some("https://mastodon.social/inbox"),
+        ),
+        make_follower(
+            "https://mastodon.social/users/b/inbox",
+            Some("https://mastodon.social/inbox"),
+        ),
+        make_follower("https://other.instance/users/c/inbox", None),
+    ];
+    let inboxes = collect_inboxes(&followers);
+    assert_eq!(inboxes.len(), 2);
+    let strs: Vec<_> = inboxes.iter().map(|u| u.as_str()).collect();
+    assert!(strs.contains(&"https://mastodon.social/inbox"));
+    assert!(strs.contains(&"https://other.instance/users/c/inbox"));
+}
+
+#[test]
+fn collect_inboxes_falls_back_to_individual_inbox() {
+    let followers = vec![make_follower("https://example.com/users/x/inbox", None)];
+    let inboxes = collect_inboxes(&followers);
+    assert_eq!(inboxes.len(), 1);
+    assert_eq!(inboxes[0].as_str(), "https://example.com/users/x/inbox");
+}

crates/adapters/activitypub-base/src/urls.rs

@@ -0,0 +1,33 @@
+use url::Url;
+
+use crate::error::Error;
+
+pub const AS_PUBLIC: &str = "https://www.w3.org/ns/activitystreams#Public";
+pub const AP_CONTEXT: &str = "https://www.w3.org/ns/activitystreams";
+pub const AP_PAGE_SIZE: usize = 20;
+
+pub fn extract_user_id_from_url(url: &Url) -> Option<uuid::Uuid> {
+    let path = url.path();
+    path.strip_prefix("/users/")
+        .and_then(|s| s.split('/').next())
+        .and_then(|s| uuid::Uuid::parse_str(s).ok())
+}
+
+pub fn activity_url(base_url: &str) -> Result<Url, Error> {
+    Url::parse(&format!("{}/activities/{}", base_url, uuid::Uuid::new_v4()))
+        .map_err(|e| Error::bad_request(anyhow::anyhow!(e)))
+}
+
+pub fn actor_url(base_url: &str, user_id: uuid::Uuid) -> Url {
+    Url::parse(&format!("{}/users/{}", base_url, user_id))
+        .expect("base_url is always a valid URL prefix")
+}
+
+/// Extract the username segment from a /users/:username URL.
+#[allow(dead_code)]
+pub fn extract_username_from_url(url: &Url) -> Option<String> {
+    url.path()
+        .strip_prefix("/users/")
+        .and_then(|s| s.split('/').next())
+        .map(|s| s.to_string())
+}

crates/adapters/activitypub-base/src/user.rs

@@ -0,0 +1,27 @@
+use async_trait::async_trait;
+use url::Url;
+
+#[derive(Debug, Clone)]
+pub struct ApProfileField {
+    pub name: String,
+    pub value: String,
+}
+
+#[derive(Debug, Clone)]
+pub struct ApUser {
+    pub id: uuid::Uuid,
+    pub username: String,
+    pub bio: Option<String>,
+    pub avatar_url: Option<Url>,
+    pub banner_url: Option<Url>,
+    pub also_known_as: Option<String>,
+    pub profile_url: Option<Url>,
+    pub attachment: Vec<ApProfileField>,
+}
+
+#[async_trait]
+pub trait ApUserRepository: Send + Sync {
+    async fn find_by_id(&self, id: uuid::Uuid) -> anyhow::Result<Option<ApUser>>;
+    async fn find_by_username(&self, username: &str) -> anyhow::Result<Option<ApUser>>;
+    async fn count_users(&self) -> anyhow::Result<usize>;
+}

crates/adapters/activitypub-base/src/webfinger.rs

@@ -0,0 +1,38 @@
+use activitypub_federation::{
+    config::Data,
+    fetch::webfinger::{Webfinger, build_webfinger_response, extract_webfinger_name},
+};
+use axum::{
+    extract::Query,
+    http::header,
+    response::{IntoResponse, Response},
+};
+use serde::Deserialize;
+
+use crate::data::FederationData;
+use crate::error::Error;
+
+#[derive(Deserialize)]
+pub struct WebfingerQuery {
+    resource: String,
+}
+
+pub async fn webfinger_handler(
+    Query(query): Query<WebfingerQuery>,
+    data: Data<FederationData>,
+) -> Result<Response, Error> {
+    let name = extract_webfinger_name(&query.resource, &data)?;
+
+    let user = data
+        .user_repo
+        .find_by_username(name)
+        .await
+        .map_err(Error::from)?
+        .ok_or_else(|| Error::not_found(anyhow::anyhow!("user not found")))?;
+
+    let ap_id = crate::urls::actor_url(&data.base_url, user.id);
+
+    let wf: Webfinger = build_webfinger_response(query.resource, ap_id);
+    let body = serde_json::to_string(&wf).map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+    Ok(([(header::CONTENT_TYPE, "application/jrd+json")], body).into_response())
+}

crates/adapters/activitypub/Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "activitypub"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+activitypub-base       = { workspace = true }
+domain                 = { workspace = true }
+url                    = { workspace = true }
+serde                  = { workspace = true }
+serde_json             = { workspace = true }
+anyhow                 = { workspace = true }
+chrono                 = { workspace = true }
+uuid                   = { workspace = true }
+async-trait            = { workspace = true }
+tracing                = { workspace = true }

crates/adapters/activitypub/src/handler.rs

@@ -0,0 +1,408 @@
+use anyhow::{anyhow, Result};
+use async_trait::async_trait;
+
+const USERS_PATH_PREFIX: &str = "/users/";
+const THOUGHTS_PATH_PREFIX: &str = "/thoughts/";
+use chrono::{DateTime, Utc};
+use std::sync::Arc;
+use url::Url;
+
+use crate::note::ThoughtNote;
+use crate::urls::ThoughtsUrls;
+use activitypub_base::{ActivityPubRepository, ApObjectHandler};
+use domain::ports::{EventPublisher, TagRepository};
+use domain::value_objects::UserId;
+
+pub struct ThoughtsObjectHandler {
+    repo: Arc<dyn ActivityPubRepository>,
+    urls: ThoughtsUrls,
+    event_publisher: Option<Arc<dyn EventPublisher>>,
+    tag_repo: Arc<dyn TagRepository>,
+}
+
+impl ThoughtsObjectHandler {
+    pub fn new(
+        repo: Arc<dyn ActivityPubRepository>,
+        base_url: &str,
+        event_publisher: Option<Arc<dyn EventPublisher>>,
+        tag_repo: Arc<dyn TagRepository>,
+    ) -> Self {
+        Self {
+            repo,
+            urls: ThoughtsUrls::new(base_url),
+            event_publisher,
+            tag_repo,
+        }
+    }
+}
+
+#[async_trait]
+impl ApObjectHandler for ThoughtsObjectHandler {
+    async fn get_local_objects_for_user(
+        &self,
+        user_id: uuid::Uuid,
+    ) -> Result<Vec<(Url, serde_json::Value)>> {
+        let uid = UserId::from_uuid(user_id);
+        let entries = self
+            .repo
+            .outbox_entries_for_actor(&uid)
+            .await
+            .map_err(|e| anyhow!("{e}"))?;
+        entries
+            .into_iter()
+            .map(|e| {
+                let note_url = self.urls.thought_url(e.thought.id.as_uuid());
+                let actor_url = self.urls.user_url(e.author_username.as_str());
+                let followers = self.urls.user_followers(e.author_username.as_str());
+                let in_reply_to = e
+                    .thought
+                    .in_reply_to_id
+                    .map(|id| self.urls.thought_url(id.as_uuid()));
+                let note = ThoughtNote::new_public(
+                    note_url.clone(),
+                    actor_url,
+                    e.thought.content.as_str().to_owned(),
+                    e.thought.created_at,
+                    in_reply_to,
+                    e.thought.sensitive,
+                    e.thought.content_warning,
+                    followers,
+                );
+                Ok((note_url, serde_json::to_value(&note)?))
+            })
+            .collect()
+    }
+
+    async fn get_local_objects_page(
+        &self,
+        user_id: uuid::Uuid,
+        before: Option<DateTime<Utc>>,
+        limit: usize,
+    ) -> Result<Vec<(Url, serde_json::Value, DateTime<Utc>)>> {
+        let uid = UserId::from_uuid(user_id);
+        let entries = self
+            .repo
+            .outbox_page_for_actor(&uid, before, limit)
+            .await
+            .map_err(|e| anyhow!("{e}"))?;
+        entries
+            .into_iter()
+            .map(|e| {
+                let created_at = e.thought.created_at;
+                let note_url = self.urls.thought_url(e.thought.id.as_uuid());
+                let actor_url = self.urls.user_url(e.author_username.as_str());
+                let followers = self.urls.user_followers(e.author_username.as_str());
+                let in_reply_to = e
+                    .thought
+                    .in_reply_to_id
+                    .map(|id| self.urls.thought_url(id.as_uuid()));
+                let note = ThoughtNote::new_public(
+                    note_url.clone(),
+                    actor_url,
+                    e.thought.content.as_str().to_owned(),
+                    created_at,
+                    in_reply_to,
+                    e.thought.sensitive,
+                    e.thought.content_warning,
+                    followers,
+                );
+                Ok((note_url, serde_json::to_value(&note)?, created_at))
+            })
+            .collect()
+    }
+
+    async fn on_create(
+        &self,
+        ap_id: &Url,
+        actor_url: &Url,
+        object: serde_json::Value,
+    ) -> Result<()> {
+        let note: ThoughtNote = serde_json::from_value(object)?;
+        let author_id = self
+            .repo
+            .intern_remote_actor(actor_url.as_str())
+            .await
+            .map_err(|e| anyhow!("{e}"))?;
+
+        // Derive visibility from AP addressing conventions.
+        let as_public = "https://www.w3.org/ns/activitystreams#Public";
+        let in_to = note.to.iter().any(|s| s == as_public);
+        let in_cc = note.cc.iter().any(|s| s == as_public);
+        let has_followers = note.to.iter().any(|s| s.ends_with("/followers"))
+            || note.cc.iter().any(|s| s.ends_with("/followers"));
+
+        let visibility = if in_to {
+            "public"
+        } else if in_cc {
+            "unlisted"
+        } else if has_followers {
+            "followers"
+        } else {
+            "direct"
+        };
+
+        let thought_id = self.repo
+            .accept_note(
+                ap_id.as_str(),
+                &author_id,
+                &note.content,
+                note.published,
+                note.sensitive,
+                note.summary,
+                visibility,
+                note.in_reply_to.as_ref().map(|u| u.as_str()),
+            )
+            .await
+            .map_err(|e| anyhow!("{e}"))?;
+
+        // Extract and index hashtags from the AP tag array.
+        let hashtag_names: Vec<String> = note
+            .tag
+            .iter()
+            .filter(|t| t.get("type").and_then(|v| v.as_str()) == Some("Hashtag"))
+            .filter_map(|t| t.get("name").and_then(|v| v.as_str()))
+            .map(|name| name.trim_start_matches('#').to_lowercase())
+            .filter(|name| !name.is_empty())
+            .collect();
+
+        for name in hashtag_names {
+            if let Ok(tag) = self.tag_repo.find_or_create(&name).await {
+                let _ = self.tag_repo.attach_to_thought(&thought_id, tag.id).await;
+            }
+        }
+
+        // Fire mention notifications for local @mentions in the note's tag array.
+        let base_url = url::Url::parse(&self.urls.base_url)
+            .ok()
+            .and_then(|u| u.host_str().map(|h| h.to_string()))
+            .unwrap_or_default();
+
+        for tag in &note.tag {
+            if tag.get("type").and_then(|t| t.as_str()) != Some("Mention") {
+                continue;
+            }
+            let href = match tag.get("href").and_then(|h| h.as_str()) {
+                Some(h) => h,
+                None => continue,
+            };
+            let href_url = match url::Url::parse(href) {
+                Ok(u) => u,
+                Err(_) => continue,
+            };
+            if href_url.host_str().unwrap_or("") != base_url {
+                continue;
+            }
+            let user_uuid = href_url
+                .path()
+                .strip_prefix(USERS_PATH_PREFIX)
+                .and_then(|s| s.split('/').next())
+                .and_then(|s| uuid::Uuid::parse_str(s).ok());
+            if let Some(uuid) = user_uuid {
+                self.on_mention(ap_id, uuid, actor_url)
+                    .await
+                    .unwrap_or_else(|e| {
+                        tracing::warn!(error = %e, "failed to process mention notification");
+                    });
+            }
+        }
+
+        Ok(())
+    }
+
+    async fn on_update(
+        &self,
+        ap_id: &Url,
+        _actor_url: &Url,
+        object: serde_json::Value,
+    ) -> Result<()> {
+        let note: ThoughtNote = serde_json::from_value(object)?;
+        self.repo
+            .apply_note_update(ap_id.as_str(), &note.content)
+            .await
+            .map_err(|e| anyhow!("{e}"))
+    }
+
+    async fn on_delete(&self, ap_id: &Url, _actor_url: &Url) -> Result<()> {
+        self.repo
+            .retract_note(ap_id.as_str())
+            .await
+            .map_err(|e| anyhow!("{e}"))
+    }
+
+    async fn on_actor_removed(&self, actor_url: &Url) -> Result<()> {
+        self.repo
+            .retract_actor_notes(actor_url.as_str())
+            .await
+            .map_err(|e| anyhow!("{e}"))
+    }
+
+    async fn on_like(&self, object_url: &Url, actor_url: &Url) -> Result<()> {
+        let thought_uuid = object_url
+            .path()
+            .strip_prefix(THOUGHTS_PATH_PREFIX)
+            .and_then(|s| s.split('/').next())
+            .and_then(|s| uuid::Uuid::parse_str(s).ok());
+
+        let thought_uuid = match thought_uuid {
+            Some(u) => u,
+            None => {
+                tracing::debug!(object = %object_url, "on_like: not a local thought URL, skipping");
+                return Ok(());
+            }
+        };
+
+        let actor_user_id = self
+            .repo
+            .find_remote_actor_id(actor_url.as_str())
+            .await
+            .map_err(|e| anyhow!("{e}"))?;
+
+        let actor_user_id = match actor_user_id {
+            Some(id) => id,
+            None => {
+                tracing::debug!(actor = %actor_url, "on_like: remote actor not interned, skipping notification");
+                return Ok(());
+            }
+        };
+
+        if let Some(ep) = &self.event_publisher {
+            let thought_id = domain::value_objects::ThoughtId::from_uuid(thought_uuid);
+            let like_id = domain::value_objects::LikeId::new();
+            ep.publish(&domain::events::DomainEvent::LikeAdded {
+                like_id,
+                user_id: actor_user_id,
+                thought_id,
+            })
+            .await
+            .map_err(|e| anyhow!("{e}"))?;
+        }
+
+        Ok(())
+    }
+
+    async fn on_unlike(&self, object_url: &url::Url, actor_url: &url::Url) -> anyhow::Result<()> {
+        let thought_uuid = object_url
+            .path()
+            .strip_prefix(THOUGHTS_PATH_PREFIX)
+            .and_then(|s| s.split('/').next())
+            .and_then(|s| uuid::Uuid::parse_str(s).ok());
+
+        let thought_uuid = match thought_uuid {
+            Some(u) => u,
+            None => {
+                tracing::debug!(object = %object_url, "on_unlike: not a local thought URL, skipping");
+                return Ok(());
+            }
+        };
+
+        let actor_user_id = self
+            .repo
+            .find_remote_actor_id(actor_url.as_str())
+            .await
+            .map_err(|e| anyhow!("{e}"))?;
+
+        let actor_user_id = match actor_user_id {
+            Some(id) => id,
+            None => {
+                tracing::debug!(actor = %actor_url, "on_unlike: remote actor not interned, skipping");
+                return Ok(());
+            }
+        };
+
+        if let Some(ep) = &self.event_publisher {
+            ep.publish(&domain::events::DomainEvent::LikeRemoved {
+                user_id: actor_user_id,
+                thought_id: domain::value_objects::ThoughtId::from_uuid(thought_uuid),
+            })
+            .await
+            .map_err(|e| anyhow!("{e}"))?;
+        }
+
+        Ok(())
+    }
+
+    async fn on_mention(
+        &self,
+        thought_ap_id: &url::Url,
+        mentioned_user_uuid: uuid::Uuid,
+        actor_url: &url::Url,
+    ) -> anyhow::Result<()> {
+        let author_user_id = match self
+            .repo
+            .find_remote_actor_id(actor_url.as_str())
+            .await
+            .map_err(|e| anyhow!("{e}"))?
+        {
+            Some(id) => id,
+            None => return Ok(()),
+        };
+
+        let thought_uuid = thought_ap_id
+            .path()
+            .strip_prefix(THOUGHTS_PATH_PREFIX)
+            .and_then(|s| s.split('/').next())
+            .and_then(|s| uuid::Uuid::parse_str(s).ok());
+
+        let thought_uuid = match thought_uuid {
+            Some(u) => u,
+            None => return Ok(()),
+        };
+
+        if let Some(ep) = &self.event_publisher {
+            ep.publish(&domain::events::DomainEvent::MentionReceived {
+                thought_id: domain::value_objects::ThoughtId::from_uuid(thought_uuid),
+                mentioned_user_id: domain::value_objects::UserId::from_uuid(mentioned_user_uuid),
+                author_user_id,
+            })
+            .await
+            .map_err(|e| anyhow!("{e}"))?;
+        }
+
+        Ok(())
+    }
+
+    async fn on_announce_received(&self, object_url: &Url, actor_url: &Url) -> Result<()> {
+        let thought_uuid = object_url
+            .path()
+            .strip_prefix(THOUGHTS_PATH_PREFIX)
+            .and_then(|s| s.split('/').next())
+            .and_then(|s| uuid::Uuid::parse_str(s).ok());
+
+        let thought_uuid = match thought_uuid {
+            Some(u) => u,
+            None => return Ok(()),
+        };
+
+        let actor_user_id = self
+            .repo
+            .find_remote_actor_id(actor_url.as_str())
+            .await
+            .map_err(|e| anyhow!("{e}"))?;
+
+        let actor_user_id = match actor_user_id {
+            Some(id) => id,
+            None => return Ok(()),
+        };
+
+        if let Some(ep) = &self.event_publisher {
+            let thought_id = domain::value_objects::ThoughtId::from_uuid(thought_uuid);
+            let boost_id = domain::value_objects::BoostId::new();
+            ep.publish(&domain::events::DomainEvent::BoostAdded {
+                boost_id,
+                user_id: actor_user_id,
+                thought_id,
+            })
+            .await
+            .map_err(|e| anyhow!("{e}"))?;
+        }
+
+        Ok(())
+    }
+
+    async fn count_local_posts(&self) -> Result<u64> {
+        self.repo
+            .count_local_notes()
+            .await
+            .map_err(|e| anyhow!("{e}"))
+    }
+}

crates/adapters/activitypub/src/lib.rs

@@ -0,0 +1,7 @@
+pub mod handler;
+pub mod note;
+pub mod urls;
+
+pub use handler::ThoughtsObjectHandler;
+pub use note::ThoughtNote;
+pub use urls::ThoughtsUrls;

crates/adapters/activitypub/src/note.rs

@@ -0,0 +1,81 @@
+use activitypub_base::NoteType;
+use activitypub_base::AS_PUBLIC;
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+use url::Url;
+
+/// AP Note representing a Thought.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct ThoughtNote {
+    #[serde(rename = "type")]
+    pub kind: NoteType,
+    pub id: Url,
+    pub url: Url, // Mastodon uses this as the clickable link
+    pub attributed_to: Url,
+    pub content: String,
+    pub published: DateTime<Utc>,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub to: Vec<String>,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub cc: Vec<String>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub in_reply_to: Option<Url>,
+    pub sensitive: bool,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub summary: Option<String>,
+    #[serde(skip_serializing_if = "Vec::is_empty", default)]
+    pub tag: Vec<serde_json::Value>,
+}
+
+impl ThoughtNote {
+    #[allow(clippy::too_many_arguments)]
+    pub fn new_public(
+        id: Url,
+        actor_url: Url,
+        content: String,
+        published: DateTime<Utc>,
+        in_reply_to: Option<Url>,
+        sensitive: bool,
+        summary: Option<String>,
+        followers_url: Url,
+    ) -> Self {
+        Self {
+            kind: Default::default(),
+            url: id.clone(),
+            id,
+            attributed_to: actor_url,
+            content,
+            published,
+            to: vec![AS_PUBLIC.to_string()],
+            cc: vec![followers_url.to_string()],
+            in_reply_to,
+            sensitive,
+            summary,
+            tag: Vec::new(),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn note_serializes_with_public_audience() {
+        let note = ThoughtNote::new_public(
+            "https://example.com/thoughts/1".parse().unwrap(),
+            "https://example.com/users/alice".parse().unwrap(),
+            "Hello world".to_string(),
+            chrono::Utc::now(),
+            None,
+            false,
+            None,
+            "https://example.com/users/alice/followers".parse().unwrap(),
+        );
+        let json = serde_json::to_string(&note).unwrap();
+        assert!(json.contains(AS_PUBLIC));
+        assert!(json.contains("Hello world"));
+        assert!(json.contains("\"url\""));
+    }
+}

crates/adapters/activitypub/src/urls.rs

@@ -0,0 +1,57 @@
+use url::Url;
+
+pub struct ThoughtsUrls {
+    pub base_url: String,
+}
+
+impl ThoughtsUrls {
+    pub fn new(base_url: &str) -> Self {
+        Self {
+            base_url: base_url.trim_end_matches('/').to_string(),
+        }
+    }
+
+    pub fn user_url(&self, username: &str) -> Url {
+        Url::parse(&format!("{}/users/{}", self.base_url, username)).expect("valid URL")
+    }
+
+    pub fn thought_url(&self, thought_id: uuid::Uuid) -> Url {
+        Url::parse(&format!("{}/thoughts/{}", self.base_url, thought_id)).expect("valid URL")
+    }
+
+    pub fn user_inbox(&self, username: &str) -> Url {
+        Url::parse(&format!("{}/users/{}/inbox", self.base_url, username)).expect("valid URL")
+    }
+
+    pub fn user_outbox(&self, username: &str) -> Url {
+        Url::parse(&format!("{}/users/{}/outbox", self.base_url, username)).expect("valid URL")
+    }
+
+    pub fn user_followers(&self, username: &str) -> Url {
+        Url::parse(&format!("{}/users/{}/followers", self.base_url, username)).expect("valid URL")
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn user_url_format() {
+        let urls = ThoughtsUrls::new("https://example.com");
+        assert_eq!(
+            urls.user_url("alice").as_str(),
+            "https://example.com/users/alice"
+        );
+    }
+
+    #[test]
+    fn thought_url_format() {
+        let urls = ThoughtsUrls::new("https://example.com");
+        let id = uuid::Uuid::nil();
+        assert!(urls
+            .thought_url(id)
+            .as_str()
+            .starts_with("https://example.com/thoughts/"));
+    }
+}

crates/adapters/auth/Cargo.toml

@@ -0,0 +1,19 @@
+[package]
+name = "auth"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+domain       = { workspace = true }
+async-trait  = { workspace = true }
+thiserror    = { workspace = true }
+uuid         = { workspace = true }
+chrono       = { workspace = true }
+tokio        = { workspace = true }
+serde        = { workspace = true }
+jsonwebtoken = "9"
+argon2       = "0.5"
+bcrypt        = "0.15"
+rand          = "0.8"
+sha2          = "0.10"
+hex           = "0.4"

crates/adapters/auth/src/api_key_service.rs

@@ -0,0 +1,89 @@
+use async_trait::async_trait;
+use domain::{
+    errors::DomainError,
+    ports::{ApiKeyRepository, ApiKeyService},
+    value_objects::UserId,
+};
+use sha2::{Digest, Sha256};
+use std::sync::Arc;
+
+pub struct ApiKeyServiceImpl {
+    repo: Arc<dyn ApiKeyRepository>,
+}
+
+impl ApiKeyServiceImpl {
+    pub fn new(repo: Arc<dyn ApiKeyRepository>) -> Self {
+        Self { repo }
+    }
+
+    fn hash(raw: &str) -> String {
+        hex::encode(Sha256::digest(raw.as_bytes()))
+    }
+}
+
+#[async_trait]
+impl ApiKeyService for ApiKeyServiceImpl {
+    async fn validate_key(&self, raw_key: &str) -> Result<Option<UserId>, DomainError> {
+        let hash = Self::hash(raw_key);
+        Ok(self.repo.find_by_hash(&hash).await?.map(|k| k.user_id))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use async_trait::async_trait;
+    use chrono::Utc;
+    use domain::{
+        errors::DomainError,
+        models::api_key::ApiKey,
+        ports::ApiKeyRepository,
+        value_objects::{ApiKeyId, UserId},
+    };
+    use std::sync::{Arc, Mutex};
+
+    struct FakeApiKeyRepo(Mutex<Vec<ApiKey>>);
+
+    #[async_trait]
+    impl ApiKeyRepository for FakeApiKeyRepo {
+        async fn save(&self, key: &ApiKey) -> Result<(), DomainError> {
+            self.0.lock().unwrap().push(key.clone());
+            Ok(())
+        }
+        async fn find_by_hash(&self, hash: &str) -> Result<Option<ApiKey>, DomainError> {
+            Ok(self.0.lock().unwrap().iter().find(|k| k.key_hash == hash).cloned())
+        }
+        async fn list_for_user(&self, _uid: &UserId) -> Result<Vec<ApiKey>, DomainError> {
+            Ok(vec![])
+        }
+        async fn delete(&self, _id: &ApiKeyId, _uid: &UserId) -> Result<(), DomainError> {
+            Ok(())
+        }
+    }
+
+    #[tokio::test]
+    async fn validate_known_key_returns_user_id() {
+        let uid = UserId::new();
+        let raw = "super-secret-key";
+        let hash = ApiKeyServiceImpl::hash(raw);
+        let key = ApiKey {
+            id: ApiKeyId::new(),
+            user_id: uid.clone(),
+            key_hash: hash,
+            name: "test".into(),
+            created_at: Utc::now(),
+        };
+        let repo = Arc::new(FakeApiKeyRepo(Mutex::new(vec![key])));
+        let svc = ApiKeyServiceImpl::new(repo);
+        let result = svc.validate_key(raw).await.unwrap();
+        assert_eq!(result.unwrap().as_uuid(), uid.as_uuid());
+    }
+
+    #[tokio::test]
+    async fn validate_unknown_key_returns_none() {
+        let repo = Arc::new(FakeApiKeyRepo(Mutex::new(vec![])));
+        let svc = ApiKeyServiceImpl::new(repo);
+        let result = svc.validate_key("unknown-key").await.unwrap();
+        assert!(result.is_none());
+    }
+}

crates/adapters/auth/src/lib.rs

@@ -0,0 +1,123 @@
+mod api_key_service;
+
+use async_trait::async_trait;
+use chrono::{Duration, Utc};
+use domain::{
+    errors::DomainError,
+    ports::{AuthService, GeneratedToken, PasswordHasher},
+    value_objects::{PasswordHash, UserId},
+};
+use jsonwebtoken::{decode, encode, DecodingKey, EncodingKey, Header, Validation};
+use serde::{Deserialize, Serialize};
+
+pub use api_key_service::ApiKeyServiceImpl;
+
+#[derive(Serialize, Deserialize)]
+struct Claims {
+    sub: String,
+    exp: usize,
+}
+
+pub struct JwtAuthService {
+    secret: String,
+    ttl_seconds: i64,
+}
+
+impl JwtAuthService {
+    pub fn new(secret: String, ttl_seconds: i64) -> Self {
+        Self {
+            secret,
+            ttl_seconds,
+        }
+    }
+}
+
+impl AuthService for JwtAuthService {
+    fn generate_token(&self, user_id: &UserId) -> Result<GeneratedToken, DomainError> {
+        let exp = (Utc::now() + Duration::seconds(self.ttl_seconds)).timestamp() as usize;
+        let claims = Claims {
+            sub: user_id.as_uuid().to_string(),
+            exp,
+        };
+        let token = encode(
+            &Header::default(),
+            &claims,
+            &EncodingKey::from_secret(self.secret.as_bytes()),
+        )
+        .map_err(|e| DomainError::Internal(e.to_string()))?;
+        Ok(GeneratedToken {
+            token,
+            user_id: user_id.clone(),
+        })
+    }
+
+    fn validate_token(&self, token: &str) -> Result<UserId, DomainError> {
+        let data = decode::<Claims>(
+            token,
+            &DecodingKey::from_secret(self.secret.as_bytes()),
+            &Validation::default(),
+        )
+        .map_err(|_| DomainError::Unauthorized)?;
+        let uuid =
+            uuid::Uuid::parse_str(&data.claims.sub).map_err(|_| DomainError::Unauthorized)?;
+        Ok(UserId::from_uuid(uuid))
+    }
+}
+
+pub struct Argon2PasswordHasher;
+
+#[async_trait]
+impl PasswordHasher for Argon2PasswordHasher {
+    async fn hash(&self, plain: &str) -> Result<PasswordHash, DomainError> {
+        use argon2::{password_hash::SaltString, Argon2, PasswordHasher as _};
+        use rand::rngs::OsRng;
+        let salt = SaltString::generate(OsRng);
+        let hash = Argon2::default()
+            .hash_password(plain.as_bytes(), &salt)
+            .map_err(|e| DomainError::Internal(e.to_string()))?
+            .to_string();
+        Ok(PasswordHash(hash))
+    }
+
+    async fn verify(&self, plain: &str, hash: &PasswordHash) -> Result<bool, DomainError> {
+        if hash.0.starts_with("$2") {
+            return bcrypt::verify(plain, &hash.0)
+                .map_err(|e| DomainError::Internal(e.to_string()));
+        }
+        use argon2::{password_hash::PasswordHash as ArgonHash, Argon2, PasswordVerifier};
+        let parsed = ArgonHash::new(&hash.0).map_err(|e| DomainError::Internal(e.to_string()))?;
+        Ok(Argon2::default()
+            .verify_password(plain.as_bytes(), &parsed)
+            .is_ok())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use domain::ports::AuthService;
+
+    #[test]
+    fn generate_and_validate_token() {
+        let svc = JwtAuthService::new("a-secret-that-is-at-least-32-bytes!!".into(), 3600);
+        let id = UserId::new();
+        let tok = svc.generate_token(&id).unwrap();
+        let parsed = svc.validate_token(&tok.token).unwrap();
+        assert_eq!(parsed.as_uuid(), id.as_uuid());
+    }
+
+    #[test]
+    fn invalid_token_returns_unauthorized() {
+        let svc = JwtAuthService::new("a-secret-that-is-at-least-32-bytes!!".into(), 3600);
+        let err = svc.validate_token("not.a.token").unwrap_err();
+        assert!(matches!(err, DomainError::Unauthorized));
+    }
+
+    #[tokio::test]
+    async fn hash_and_verify() {
+        let hasher = Argon2PasswordHasher;
+        let hash = hasher.hash("mypassword").await.unwrap();
+        assert!(hasher.verify("mypassword", &hash).await.unwrap());
+        assert!(!hasher.verify("wrongpassword", &hash).await.unwrap());
+    }
+}

crates/adapters/event-payload/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "event-payload"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+serde      = { workspace = true }
+serde_json = { workspace = true }
+domain     = { workspace = true }
+uuid       = { workspace = true }

crates/adapters/event-payload/src/lib.rs

@@ -0,0 +1,446 @@
+use domain::{
+    errors::DomainError,
+    events::DomainEvent,
+    value_objects::{BoostId, LikeId, ThoughtId, UserId},
+};
+use serde::{Deserialize, Serialize};
+
+/// Serializable mirror of domain::events::DomainEvent.
+/// All IDs are Strings (UUID hex) — no domain type dependencies.
+#[derive(Debug, Clone, Serialize, Deserialize)]
+#[serde(tag = "type", content = "data")]
+pub enum EventPayload {
+    ThoughtCreated {
+        thought_id: String,
+        user_id: String,
+        in_reply_to_id: Option<String>,
+    },
+    ThoughtDeleted {
+        thought_id: String,
+        user_id: String,
+    },
+    ThoughtUpdated {
+        thought_id: String,
+        user_id: String,
+    },
+    LikeAdded {
+        like_id: String,
+        user_id: String,
+        thought_id: String,
+    },
+    LikeRemoved {
+        user_id: String,
+        thought_id: String,
+    },
+    BoostAdded {
+        boost_id: String,
+        user_id: String,
+        thought_id: String,
+    },
+    BoostRemoved {
+        user_id: String,
+        thought_id: String,
+    },
+    FollowRequested {
+        follower_id: String,
+        following_id: String,
+    },
+    FollowAccepted {
+        follower_id: String,
+        following_id: String,
+    },
+    FollowRejected {
+        follower_id: String,
+        following_id: String,
+    },
+    Unfollowed {
+        follower_id: String,
+        following_id: String,
+    },
+    UserBlocked {
+        blocker_id: String,
+        blocked_id: String,
+    },
+    UserUnblocked {
+        blocker_id: String,
+        blocked_id: String,
+    },
+    UserRegistered {
+        user_id: String,
+    },
+    ProfileUpdated {
+        user_id: String,
+    },
+    MentionReceived {
+        thought_id: String,
+        mentioned_user_id: String,
+        author_user_id: String,
+    },
+}
+
+impl EventPayload {
+    /// Returns the NATS subject for this event.
+    pub fn subject(&self) -> &'static str {
+        match self {
+            Self::ThoughtCreated { .. } => "thoughts.created",
+            Self::ThoughtDeleted { .. } => "thoughts.deleted",
+            Self::ThoughtUpdated { .. } => "thoughts.updated",
+            Self::LikeAdded { .. } => "likes.added",
+            Self::LikeRemoved { .. } => "likes.removed",
+            Self::BoostAdded { .. } => "boosts.added",
+            Self::BoostRemoved { .. } => "boosts.removed",
+            Self::FollowRequested { .. } => "follows.requested",
+            Self::FollowAccepted { .. } => "follows.accepted",
+            Self::FollowRejected { .. } => "follows.rejected",
+            Self::Unfollowed { .. } => "follows.removed",
+            Self::UserBlocked { .. } => "users.blocked",
+            Self::UserUnblocked { .. } => "users.unblocked",
+            Self::UserRegistered { .. } => "users.registered",
+            Self::ProfileUpdated { .. } => "users.profile_updated",
+            Self::MentionReceived { .. } => "mentions.received",
+        }
+    }
+}
+
+// ── DomainEvent → EventPayload ─────────────────────────────────────────────
+
+impl From<&DomainEvent> for EventPayload {
+    fn from(e: &DomainEvent) -> Self {
+        match e {
+            DomainEvent::ThoughtCreated {
+                thought_id,
+                user_id,
+                in_reply_to_id,
+            } => Self::ThoughtCreated {
+                thought_id: thought_id.to_string(),
+                user_id: user_id.to_string(),
+                in_reply_to_id: in_reply_to_id.as_ref().map(|x| x.to_string()),
+            },
+            DomainEvent::ThoughtDeleted {
+                thought_id,
+                user_id,
+            } => Self::ThoughtDeleted {
+                thought_id: thought_id.to_string(),
+                user_id: user_id.to_string(),
+            },
+            DomainEvent::ThoughtUpdated {
+                thought_id,
+                user_id,
+            } => Self::ThoughtUpdated {
+                thought_id: thought_id.to_string(),
+                user_id: user_id.to_string(),
+            },
+            DomainEvent::LikeAdded {
+                like_id,
+                user_id,
+                thought_id,
+            } => Self::LikeAdded {
+                like_id: like_id.to_string(),
+                user_id: user_id.to_string(),
+                thought_id: thought_id.to_string(),
+            },
+            DomainEvent::LikeRemoved {
+                user_id,
+                thought_id,
+            } => Self::LikeRemoved {
+                user_id: user_id.to_string(),
+                thought_id: thought_id.to_string(),
+            },
+            DomainEvent::BoostAdded {
+                boost_id,
+                user_id,
+                thought_id,
+            } => Self::BoostAdded {
+                boost_id: boost_id.to_string(),
+                user_id: user_id.to_string(),
+                thought_id: thought_id.to_string(),
+            },
+            DomainEvent::BoostRemoved {
+                user_id,
+                thought_id,
+            } => Self::BoostRemoved {
+                user_id: user_id.to_string(),
+                thought_id: thought_id.to_string(),
+            },
+            DomainEvent::FollowRequested {
+                follower_id,
+                following_id,
+            } => Self::FollowRequested {
+                follower_id: follower_id.to_string(),
+                following_id: following_id.to_string(),
+            },
+            DomainEvent::FollowAccepted {
+                follower_id,
+                following_id,
+            } => Self::FollowAccepted {
+                follower_id: follower_id.to_string(),
+                following_id: following_id.to_string(),
+            },
+            DomainEvent::FollowRejected {
+                follower_id,
+                following_id,
+            } => Self::FollowRejected {
+                follower_id: follower_id.to_string(),
+                following_id: following_id.to_string(),
+            },
+            DomainEvent::Unfollowed {
+                follower_id,
+                following_id,
+            } => Self::Unfollowed {
+                follower_id: follower_id.to_string(),
+                following_id: following_id.to_string(),
+            },
+            DomainEvent::UserBlocked {
+                blocker_id,
+                blocked_id,
+            } => Self::UserBlocked {
+                blocker_id: blocker_id.to_string(),
+                blocked_id: blocked_id.to_string(),
+            },
+            DomainEvent::UserUnblocked {
+                blocker_id,
+                blocked_id,
+            } => Self::UserUnblocked {
+                blocker_id: blocker_id.to_string(),
+                blocked_id: blocked_id.to_string(),
+            },
+            DomainEvent::UserRegistered { user_id } => Self::UserRegistered {
+                user_id: user_id.to_string(),
+            },
+            DomainEvent::ProfileUpdated { user_id } => Self::ProfileUpdated {
+                user_id: user_id.to_string(),
+            },
+            DomainEvent::MentionReceived {
+                thought_id,
+                mentioned_user_id,
+                author_user_id,
+            } => Self::MentionReceived {
+                thought_id: thought_id.to_string(),
+                mentioned_user_id: mentioned_user_id.to_string(),
+                author_user_id: author_user_id.to_string(),
+            },
+        }
+    }
+}
+
+// ── EventPayload → DomainEvent ─────────────────────────────────────────────
+
+fn parse_uuid(s: &str, field: &str) -> Result<uuid::Uuid, DomainError> {
+    uuid::Uuid::parse_str(s)
+        .map_err(|_| DomainError::Internal(format!("invalid uuid for {field}: {s}")))
+}
+
+impl TryFrom<EventPayload> for DomainEvent {
+    type Error = DomainError;
+
+    fn try_from(p: EventPayload) -> Result<Self, DomainError> {
+        Ok(match p {
+            EventPayload::ThoughtCreated {
+                thought_id,
+                user_id,
+                in_reply_to_id,
+            } => DomainEvent::ThoughtCreated {
+                thought_id: ThoughtId::from_uuid(parse_uuid(&thought_id, "thought_id")?),
+                user_id: UserId::from_uuid(parse_uuid(&user_id, "user_id")?),
+                in_reply_to_id: in_reply_to_id
+                    .map(|s| parse_uuid(&s, "in_reply_to_id").map(ThoughtId::from_uuid))
+                    .transpose()?,
+            },
+            EventPayload::ThoughtDeleted {
+                thought_id,
+                user_id,
+            } => DomainEvent::ThoughtDeleted {
+                thought_id: ThoughtId::from_uuid(parse_uuid(&thought_id, "thought_id")?),
+                user_id: UserId::from_uuid(parse_uuid(&user_id, "user_id")?),
+            },
+            EventPayload::ThoughtUpdated {
+                thought_id,
+                user_id,
+            } => DomainEvent::ThoughtUpdated {
+                thought_id: ThoughtId::from_uuid(parse_uuid(&thought_id, "thought_id")?),
+                user_id: UserId::from_uuid(parse_uuid(&user_id, "user_id")?),
+            },
+            EventPayload::LikeAdded {
+                like_id,
+                user_id,
+                thought_id,
+            } => DomainEvent::LikeAdded {
+                like_id: LikeId::from_uuid(parse_uuid(&like_id, "like_id")?),
+                user_id: UserId::from_uuid(parse_uuid(&user_id, "user_id")?),
+                thought_id: ThoughtId::from_uuid(parse_uuid(&thought_id, "thought_id")?),
+            },
+            EventPayload::LikeRemoved {
+                user_id,
+                thought_id,
+            } => DomainEvent::LikeRemoved {
+                user_id: UserId::from_uuid(parse_uuid(&user_id, "user_id")?),
+                thought_id: ThoughtId::from_uuid(parse_uuid(&thought_id, "thought_id")?),
+            },
+            EventPayload::BoostAdded {
+                boost_id,
+                user_id,
+                thought_id,
+            } => DomainEvent::BoostAdded {
+                boost_id: BoostId::from_uuid(parse_uuid(&boost_id, "boost_id")?),
+                user_id: UserId::from_uuid(parse_uuid(&user_id, "user_id")?),
+                thought_id: ThoughtId::from_uuid(parse_uuid(&thought_id, "thought_id")?),
+            },
+            EventPayload::BoostRemoved {
+                user_id,
+                thought_id,
+            } => DomainEvent::BoostRemoved {
+                user_id: UserId::from_uuid(parse_uuid(&user_id, "user_id")?),
+                thought_id: ThoughtId::from_uuid(parse_uuid(&thought_id, "thought_id")?),
+            },
+            EventPayload::FollowRequested {
+                follower_id,
+                following_id,
+            } => DomainEvent::FollowRequested {
+                follower_id: UserId::from_uuid(parse_uuid(&follower_id, "follower_id")?),
+                following_id: UserId::from_uuid(parse_uuid(&following_id, "following_id")?),
+            },
+            EventPayload::FollowAccepted {
+                follower_id,
+                following_id,
+            } => DomainEvent::FollowAccepted {
+                follower_id: UserId::from_uuid(parse_uuid(&follower_id, "follower_id")?),
+                following_id: UserId::from_uuid(parse_uuid(&following_id, "following_id")?),
+            },
+            EventPayload::FollowRejected {
+                follower_id,
+                following_id,
+            } => DomainEvent::FollowRejected {
+                follower_id: UserId::from_uuid(parse_uuid(&follower_id, "follower_id")?),
+                following_id: UserId::from_uuid(parse_uuid(&following_id, "following_id")?),
+            },
+            EventPayload::Unfollowed {
+                follower_id,
+                following_id,
+            } => DomainEvent::Unfollowed {
+                follower_id: UserId::from_uuid(parse_uuid(&follower_id, "follower_id")?),
+                following_id: UserId::from_uuid(parse_uuid(&following_id, "following_id")?),
+            },
+            EventPayload::UserBlocked {
+                blocker_id,
+                blocked_id,
+            } => DomainEvent::UserBlocked {
+                blocker_id: UserId::from_uuid(parse_uuid(&blocker_id, "blocker_id")?),
+                blocked_id: UserId::from_uuid(parse_uuid(&blocked_id, "blocked_id")?),
+            },
+            EventPayload::UserUnblocked {
+                blocker_id,
+                blocked_id,
+            } => DomainEvent::UserUnblocked {
+                blocker_id: UserId::from_uuid(parse_uuid(&blocker_id, "blocker_id")?),
+                blocked_id: UserId::from_uuid(parse_uuid(&blocked_id, "blocked_id")?),
+            },
+            EventPayload::UserRegistered { user_id } => DomainEvent::UserRegistered {
+                user_id: UserId::from_uuid(parse_uuid(&user_id, "user_id")?),
+            },
+            EventPayload::ProfileUpdated { user_id } => DomainEvent::ProfileUpdated {
+                user_id: UserId::from_uuid(parse_uuid(&user_id, "user_id")?),
+            },
+            EventPayload::MentionReceived {
+                thought_id,
+                mentioned_user_id,
+                author_user_id,
+            } => DomainEvent::MentionReceived {
+                thought_id: ThoughtId::from_uuid(parse_uuid(&thought_id, "thought_id")?),
+                mentioned_user_id: UserId::from_uuid(parse_uuid(
+                    &mentioned_user_id,
+                    "mentioned_user_id",
+                )?),
+                author_user_id: UserId::from_uuid(parse_uuid(&author_user_id, "author_user_id")?),
+            },
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn thought_created_roundtrip() {
+        let p = EventPayload::ThoughtCreated {
+            thought_id: "abc".into(),
+            user_id: "def".into(),
+            in_reply_to_id: None,
+        };
+        let json = serde_json::to_string(&p).unwrap();
+        let back: EventPayload = serde_json::from_str(&json).unwrap();
+        assert_eq!(back.subject(), "thoughts.created");
+    }
+
+    #[test]
+    fn all_subjects_are_unique() {
+        let samples: &[EventPayload] = &[
+            EventPayload::ThoughtCreated {
+                thought_id: "a".into(),
+                user_id: "b".into(),
+                in_reply_to_id: None,
+            },
+            EventPayload::ThoughtDeleted {
+                thought_id: "a".into(),
+                user_id: "b".into(),
+            },
+            EventPayload::ThoughtUpdated {
+                thought_id: "a".into(),
+                user_id: "b".into(),
+            },
+            EventPayload::LikeAdded {
+                like_id: "a".into(),
+                user_id: "b".into(),
+                thought_id: "c".into(),
+            },
+            EventPayload::LikeRemoved {
+                user_id: "b".into(),
+                thought_id: "c".into(),
+            },
+            EventPayload::BoostAdded {
+                boost_id: "a".into(),
+                user_id: "b".into(),
+                thought_id: "c".into(),
+            },
+            EventPayload::BoostRemoved {
+                user_id: "b".into(),
+                thought_id: "c".into(),
+            },
+            EventPayload::FollowRequested {
+                follower_id: "a".into(),
+                following_id: "b".into(),
+            },
+            EventPayload::FollowAccepted {
+                follower_id: "a".into(),
+                following_id: "b".into(),
+            },
+            EventPayload::FollowRejected {
+                follower_id: "a".into(),
+                following_id: "b".into(),
+            },
+            EventPayload::Unfollowed {
+                follower_id: "a".into(),
+                following_id: "b".into(),
+            },
+            EventPayload::UserBlocked {
+                blocker_id: "a".into(),
+                blocked_id: "b".into(),
+            },
+            EventPayload::UserUnblocked {
+                blocker_id: "a".into(),
+                blocked_id: "b".into(),
+            },
+            EventPayload::UserRegistered {
+                user_id: "a".into(),
+            },
+        ];
+        let mut subjects: Vec<&str> = samples.iter().map(|p| p.subject()).collect();
+        subjects.sort();
+        subjects.dedup();
+        assert_eq!(
+            subjects.len(),
+            samples.len(),
+            "each event must have a unique subject"
+        );
+    }
+}

crates/adapters/event-transport/Cargo.toml

@@ -0,0 +1,15 @@
+[package]
+name = "event-transport"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+domain        = { workspace = true }
+event-payload = { workspace = true }
+serde_json    = { workspace = true }
+async-trait   = { workspace = true }
+tracing       = { workspace = true }
+futures       = { workspace = true }
+
+[dev-dependencies]
+tokio = { workspace = true, features = ["full"] }

crates/adapters/event-transport/src/lib.rs

@@ -0,0 +1,236 @@
+use async_trait::async_trait;
+use domain::{
+    errors::DomainError,
+    events::{DomainEvent, EventEnvelope},
+    ports::{EventConsumer, EventPublisher},
+};
+use event_payload::EventPayload;
+use futures::stream::BoxStream;
+
+/// Abstraction over any pub/sub transport backend.
+/// Implement this for NATS, Kafka, Redis Streams, etc.
+/// The adapter calls `publish_bytes(subject, bytes)` — subjects come from `EventPayload::subject()`.
+#[async_trait]
+pub trait Transport: Send + Sync {
+    async fn publish_bytes(&self, subject: &str, bytes: &[u8]) -> Result<(), DomainError>;
+}
+
+/// Routes domain events to a transport backend.
+///
+/// Converts: `DomainEvent` → `EventPayload` → JSON bytes → `transport.publish_bytes(subject, bytes)`
+///
+/// To swap transports (e.g. NATS → Kafka), replace the `T` at the composition root.
+pub struct EventPublisherAdapter<T: Transport> {
+    transport: T,
+}
+
+impl<T: Transport> EventPublisherAdapter<T> {
+    pub fn new(transport: T) -> Self {
+        Self { transport }
+    }
+}
+
+#[async_trait]
+impl<T: Transport> EventPublisher for EventPublisherAdapter<T> {
+    async fn publish(&self, event: &DomainEvent) -> Result<(), DomainError> {
+        let payload = EventPayload::from(event);
+        let subject = payload.subject();
+        let bytes =
+            serde_json::to_vec(&payload).map_err(|e| DomainError::Internal(e.to_string()))?;
+        tracing::debug!(subject, "publishing event");
+        self.transport.publish_bytes(subject, &bytes).await
+    }
+}
+
+/// A raw inbound message from a transport backend.
+/// `ack` and `nack` are transport-level acknowledgements (e.g. Kafka offset commit).
+/// For at-most-once transports (basic NATS), both are no-ops.
+pub struct RawMessage {
+    pub subject: String,
+    pub payload: Vec<u8>,
+    pub delivery_count: u64,
+    pub ack: Box<dyn Fn() + Send + Sync>,
+    pub nack: Box<dyn Fn() + Send + Sync>,
+}
+
+/// Abstraction over any subscribe/consume backend.
+pub trait MessageSource: Send + Sync {
+    fn messages(&self) -> BoxStream<'_, Result<RawMessage, DomainError>>;
+}
+
+/// Deserializes raw transport messages into domain `EventEnvelope`s.
+/// Invalid or unknown messages are skipped with a warning — stream continues.
+pub struct EventConsumerAdapter<S: MessageSource> {
+    source: S,
+}
+
+impl<S: MessageSource> EventConsumerAdapter<S> {
+    pub fn new(source: S) -> Self {
+        Self { source }
+    }
+}
+
+impl<S: MessageSource> EventConsumer for EventConsumerAdapter<S> {
+    fn consume(&self) -> BoxStream<'_, Result<EventEnvelope, DomainError>> {
+        use futures::StreamExt;
+        let stream = self.source.messages();
+        Box::pin(stream.filter_map(|result| async move {
+            match result {
+                Err(e) => {
+                    tracing::warn!("transport error: {e}");
+                    None
+                }
+                Ok(msg) => {
+                    let payload = match serde_json::from_slice::<EventPayload>(&msg.payload) {
+                        Ok(p) => p,
+                        Err(e) => {
+                            tracing::warn!("failed to deserialize event payload — acking to prevent orphan: {e}");
+                            (msg.ack)();
+                            return None;
+                        }
+                    };
+                    let event = match DomainEvent::try_from(payload) {
+                        Ok(e) => e,
+                        Err(e) => {
+                            tracing::warn!("unknown or malformed event type — acking to prevent orphan: {e}");
+                            (msg.ack)();
+                            return None;
+                        }
+                    };
+                    Some(Ok(EventEnvelope {
+                        event,
+                        delivery_count: msg.delivery_count,
+                        ack: msg.ack,
+                        nack: msg.nack,
+                    }))
+                }
+            }
+        }))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use async_trait::async_trait;
+    use domain::value_objects::{ThoughtId, UserId};
+    use std::sync::{Arc, Mutex};
+
+    struct SpyTransport {
+        calls: Arc<Mutex<Vec<(String, Vec<u8>)>>>,
+    }
+    impl SpyTransport {
+        fn new() -> (Self, Arc<Mutex<Vec<(String, Vec<u8>)>>>) {
+            let calls = Arc::new(Mutex::new(vec![]));
+            (
+                Self {
+                    calls: calls.clone(),
+                },
+                calls,
+            )
+        }
+    }
+    #[async_trait]
+    impl Transport for SpyTransport {
+        async fn publish_bytes(&self, subject: &str, bytes: &[u8]) -> Result<(), DomainError> {
+            self.calls
+                .lock()
+                .unwrap()
+                .push((subject.to_string(), bytes.to_vec()));
+            Ok(())
+        }
+    }
+
+    #[tokio::test]
+    async fn thought_created_routes_to_correct_subject() {
+        let (spy, calls) = SpyTransport::new();
+        let publisher = EventPublisherAdapter::new(spy);
+        publisher
+            .publish(&DomainEvent::ThoughtCreated {
+                thought_id: ThoughtId::new(),
+                user_id: UserId::new(),
+                in_reply_to_id: None,
+            })
+            .await
+            .unwrap();
+        let calls = calls.lock().unwrap();
+        assert_eq!(calls.len(), 1);
+        assert_eq!(calls[0].0, "thoughts.created");
+    }
+
+    #[tokio::test]
+    async fn serialized_payload_is_valid_json() {
+        let (spy, calls) = SpyTransport::new();
+        let publisher = EventPublisherAdapter::new(spy);
+        publisher
+            .publish(&DomainEvent::UserBlocked {
+                blocker_id: UserId::new(),
+                blocked_id: UserId::new(),
+            })
+            .await
+            .unwrap();
+        let bytes = calls.lock().unwrap()[0].1.clone();
+        let json: serde_json::Value = serde_json::from_slice(&bytes).expect("valid JSON");
+        assert_eq!(json["type"], "UserBlocked");
+    }
+
+    #[tokio::test]
+    async fn consumer_adapter_deserializes_and_yields_event() {
+        use domain::value_objects::ThoughtId;
+        use futures::StreamExt;
+
+        let event = DomainEvent::ThoughtCreated {
+            thought_id: ThoughtId::new(),
+            user_id: UserId::new(),
+            in_reply_to_id: None,
+        };
+        let payload = EventPayload::from(&event);
+        let bytes = serde_json::to_vec(&payload).unwrap();
+
+        struct OneMessageSource {
+            bytes: Vec<u8>,
+        }
+        #[async_trait::async_trait]
+        impl MessageSource for OneMessageSource {
+            fn messages(&self) -> futures::stream::BoxStream<'_, Result<RawMessage, DomainError>> {
+                let msg = RawMessage {
+                    subject: "thoughts.created".to_string(),
+                    payload: self.bytes.clone(),
+                    delivery_count: 1,
+                    ack: Box::new(|| {}),
+                    nack: Box::new(|| {}),
+                };
+                Box::pin(futures::stream::once(async { Ok(msg) }))
+            }
+        }
+
+        let adapter = EventConsumerAdapter::new(OneMessageSource { bytes });
+        let mut stream = adapter.consume();
+        let envelope = stream.next().await.unwrap().unwrap();
+        assert!(matches!(envelope.event, DomainEvent::ThoughtCreated { .. }));
+    }
+
+    #[tokio::test]
+    async fn consumer_adapter_skips_invalid_payloads() {
+        use futures::StreamExt;
+
+        struct BadMessageSource;
+        #[async_trait::async_trait]
+        impl MessageSource for BadMessageSource {
+            fn messages(&self) -> futures::stream::BoxStream<'_, Result<RawMessage, DomainError>> {
+                let msg = RawMessage {
+                    subject: "bad".to_string(),
+                    payload: b"not valid json".to_vec(),
+                    delivery_count: 1,
+                    ack: Box::new(|| {}),
+                    nack: Box::new(|| {}),
+                };
+                Box::pin(futures::stream::once(async { Ok(msg) }))
+            }
+        }
+
+        let adapter = EventConsumerAdapter::new(BadMessageSource);
+        let mut stream = adapter.consume();
+        assert!(stream.next().await.is_none());
+    }
+}

crates/adapters/nats/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "nats"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+domain           = { workspace = true }
+event-payload    = { workspace = true }
+event-transport  = { workspace = true }
+async-nats       = { workspace = true }
+async-stream     = { workspace = true }
+serde_json       = { workspace = true }
+futures          = { workspace = true }
+tokio            = { workspace = true }
+async-trait      = { workspace = true }
+tracing          = { workspace = true }
+uuid             = { workspace = true }

crates/adapters/nats/src/lib.rs

@@ -0,0 +1,285 @@
+use async_nats::jetstream::{self, stream::Config as StreamConfig, AckKind};
+use async_trait::async_trait;
+use domain::errors::DomainError;
+use event_transport::{MessageSource, RawMessage, Transport};
+use futures::stream::BoxStream;
+use std::sync::Arc;
+
+const STREAM_NAME: &str = "THOUGHTS_EVENTS";
+const STREAM_SUBJECT: &str = "thoughts-events.>";
+const CONSUMER_NAME: &str = "worker";
+const MAX_MESSAGES: i64 = 100_000;
+
+/// Maximum NATS delivery attempts before a message is considered exhausted.
+pub const CONSUMER_MAX_DELIVER: i64 = 5;
+/// How long NATS waits for an ack before redelivering.
+const CONSUMER_ACK_WAIT_SECS: u64 = 30;
+/// Timeout for spawned ack/nack async tasks.
+const ACK_TASK_TIMEOUT_SECS: u64 = 5;
+
+fn stream_config() -> StreamConfig {
+    StreamConfig {
+        name: STREAM_NAME.to_string(),
+        subjects: vec![STREAM_SUBJECT.to_string()],
+        max_messages: MAX_MESSAGES,
+        ..Default::default()
+    }
+}
+
+/// Ensure the JetStream stream exists with the current config.
+/// If an incompatible stream exists (e.g. wrong retention policy), deletes and recreates it.
+pub async fn ensure_stream(client: &async_nats::Client) -> Result<(), DomainError> {
+    let js = jetstream::new(client.clone());
+
+    // Happy path: stream exists and config is compatible.
+    if js.update_stream(stream_config()).await.is_ok() {
+        tracing::info!(subject = STREAM_SUBJECT, "JetStream stream updated");
+        return Ok(());
+    }
+
+    // Update failed — retention policy mismatch or other incompatibility.
+    // Delete the old stream and recreate with current config.
+    tracing::warn!(
+        "JetStream stream update failed (incompatible config), deleting '{STREAM_NAME}' and recreating"
+    );
+    let _ = js.delete_stream(STREAM_NAME).await;
+
+    js.create_stream(stream_config())
+        .await
+        .map(|_| ())
+        .map_err(|e| DomainError::Internal(format!("JetStream stream create failed: {e}")))
+}
+
+// ── NatsTransport — JetStream publish ──────────────────────────────────────
+
+pub struct NatsTransport {
+    jetstream: jetstream::Context,
+}
+
+impl NatsTransport {
+    pub fn new(client: async_nats::Client) -> Self {
+        Self {
+            jetstream: jetstream::new(client),
+        }
+    }
+}
+
+#[async_trait]
+impl Transport for NatsTransport {
+    async fn publish_bytes(&self, subject: &str, bytes: &[u8]) -> Result<(), DomainError> {
+        // Prefix all subjects so they land inside the stream's subject filter.
+        let full_subject = format!("thoughts-events.{subject}");
+        self.jetstream
+            .publish(full_subject, bytes.to_vec().into())
+            .await
+            .map_err(|e| DomainError::Internal(e.to_string()))?
+            .await // wait for server ack — confirms message is durably stored
+            .map_err(|e| DomainError::Internal(e.to_string()))?;
+        Ok(())
+    }
+}
+
+// ── NatsMessageSource — JetStream durable push consumer ────────────────────
+
+pub struct NatsMessageSource {
+    jetstream: jetstream::Context,
+}
+
+impl NatsMessageSource {
+    pub fn new(client: async_nats::Client) -> Self {
+        Self {
+            jetstream: jetstream::new(client),
+        }
+    }
+}
+
+impl MessageSource for NatsMessageSource {
+    fn messages(&self) -> BoxStream<'_, Result<RawMessage, DomainError>> {
+        use futures::stream;
+        use tokio::sync::{mpsc, Mutex as TokioMutex};
+
+        let js = self.jetstream.clone();
+        let (tx, rx) = mpsc::channel::<Result<RawMessage, DomainError>>(128);
+
+        // Spawn the consumer loop in the background.
+        // Pull consumer: worker explicitly fetches from NATS rather than NATS pushing.
+        tokio::spawn(async move {
+            let stream = match js.get_stream(STREAM_NAME).await {
+                Ok(s) => s,
+                Err(e) => {
+                    let _ = tx.send(Err(DomainError::Internal(e.to_string()))).await;
+                    return;
+                }
+            };
+
+            // Delete any existing push consumer with this name — can't reuse as pull.
+            // No-op if it doesn't exist or is already a pull consumer.
+            if let Ok(info) = stream.consumer_info(CONSUMER_NAME).await {
+                if info.config.deliver_subject.is_some() {
+                    tracing::info!(
+                        "deleting old push consumer '{CONSUMER_NAME}', replacing with pull"
+                    );
+                    let _ = stream.delete_consumer(CONSUMER_NAME).await;
+                }
+            }
+
+            let consumer = match stream
+                .get_or_create_consumer(
+                    CONSUMER_NAME,
+                    jetstream::consumer::pull::Config {
+                        durable_name: Some(CONSUMER_NAME.to_string()),
+                        deliver_policy: jetstream::consumer::DeliverPolicy::New,
+                        ack_policy: jetstream::consumer::AckPolicy::Explicit,
+                        ack_wait: std::time::Duration::from_secs(CONSUMER_ACK_WAIT_SECS),
+                        max_deliver: CONSUMER_MAX_DELIVER,
+                        // No filter_subject — consume everything from the stream.
+                        // filter_subject matching the stream's own wildcard can be
+                        // inconsistent across NATS server versions.
+                        ..Default::default()
+                    },
+                )
+                .await
+            {
+                Ok(c) => c,
+                Err(e) => {
+                    let _ = tx.send(Err(DomainError::Internal(e.to_string()))).await;
+                    return;
+                }
+            };
+
+            tracing::info!("NATS pull consumer ready");
+
+            loop {
+                // consumer.messages() uses long-poll (no no_wait flag) — NATS holds the
+                // request open and delivers messages as they arrive.
+                // fetch() in async-nats 0.48 defaults to no_wait:true which returns
+                // immediately when the queue is empty, so we avoid it here.
+                let mut messages = match consumer.messages().await {
+                    Ok(m) => m,
+                    Err(e) => {
+                        tracing::error!("NATS messages() failed: {e}");
+                        let _ = tx.send(Err(DomainError::Internal(e.to_string()))).await;
+                        return;
+                    }
+                };
+
+                use futures::StreamExt;
+                while let Some(result) = messages.next().await {
+                    let msg = match result {
+                        Ok(m) => m,
+                        Err(e) => {
+                            tracing::warn!("NATS message error: {e}");
+                            continue;
+                        }
+                    };
+
+                    let subject = msg.subject.to_string();
+                    let payload = msg.payload.to_vec();
+                    let delivery_count = msg
+                        .info()
+                        .map(|info| info.delivered.max(0) as u64)
+                        .unwrap_or(1);
+                    let msg = Arc::new(msg);
+                    let msg_nack = Arc::clone(&msg);
+
+                    let raw = RawMessage {
+                        subject,
+                        payload,
+                        delivery_count,
+                        ack: Box::new(move || {
+                            let m = Arc::clone(&msg);
+                            tokio::spawn(async move {
+                                let result = tokio::time::timeout(
+                                    std::time::Duration::from_secs(ACK_TASK_TIMEOUT_SECS),
+                                    m.ack(),
+                                )
+                                .await;
+                                match result {
+                                    Ok(Ok(())) => {}
+                                    Ok(Err(e)) => tracing::warn!("NATS ack failed: {e}"),
+                                    Err(_) => tracing::warn!(
+                                        "NATS ack timed out after {ACK_TASK_TIMEOUT_SECS}s"
+                                    ),
+                                }
+                            });
+                        }),
+                        nack: Box::new(move || {
+                            let m = Arc::clone(&msg_nack);
+                            tokio::spawn(async move {
+                                let result = tokio::time::timeout(
+                                    std::time::Duration::from_secs(ACK_TASK_TIMEOUT_SECS),
+                                    m.ack_with(AckKind::Nak(None)),
+                                )
+                                .await;
+                                match result {
+                                    Ok(Ok(())) => {}
+                                    Ok(Err(e)) => tracing::warn!("NATS nack failed: {e}"),
+                                    Err(_) => tracing::warn!(
+                                        "NATS nack timed out after {ACK_TASK_TIMEOUT_SECS}s"
+                                    ),
+                                }
+                            });
+                        }),
+                    };
+
+                    if tx.send(Ok(raw)).await.is_err() {
+                        return; // receiver dropped — worker shutting down
+                    }
+                }
+                // messages() stream ended (e.g. fetch timeout) — loop and restart
+            }
+        });
+
+        // Bridge the channel receiver into a BoxStream.
+        let rx = Arc::new(TokioMutex::new(rx));
+        Box::pin(stream::unfold(rx, |rx| async move {
+            let item = rx.lock().await.recv().await?;
+            Some((item, rx))
+        }))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use domain::{
+        events::DomainEvent,
+        value_objects::{LikeId, ThoughtId, UserId},
+    };
+    use event_payload::EventPayload;
+
+    #[test]
+    fn payload_from_domain_event_has_correct_subject() {
+        let event = DomainEvent::ThoughtCreated {
+            thought_id: ThoughtId::new(),
+            user_id: UserId::new(),
+            in_reply_to_id: None,
+        };
+        let payload = EventPayload::from(&event);
+        assert_eq!(payload.subject(), "thoughts.created");
+    }
+
+    #[test]
+    fn domain_event_roundtrip_via_payload() {
+        let uid = UserId::new();
+        let tid = ThoughtId::new();
+        let event = DomainEvent::LikeAdded {
+            like_id: LikeId::new(),
+            user_id: uid.clone(),
+            thought_id: tid.clone(),
+        };
+        let payload = EventPayload::from(&event);
+        let back = DomainEvent::try_from(payload).unwrap();
+        if let DomainEvent::LikeAdded {
+            user_id,
+            thought_id,
+            ..
+        } = back
+        {
+            assert_eq!(user_id, uid);
+            assert_eq!(thought_id, tid);
+        } else {
+            panic!("wrong variant");
+        }
+    }
+}

crates/adapters/postgres-federation/Cargo.toml

@@ -0,0 +1,18 @@
+[package]
+name = "postgres-federation"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+activitypub-base = { workspace = true }
+sqlx        = { workspace = true }
+uuid        = { workspace = true }
+chrono      = { workspace = true }
+tracing     = { workspace = true }
+async-trait = { workspace = true }
+anyhow      = { workspace = true }
+url         = { workspace = true }
+
+[dev-dependencies]
+tokio = { workspace = true, features = ["full"] }
+sqlx  = { workspace = true, features = ["migrate"] }

crates/adapters/postgres-federation/src/lib.rs

@@ -0,0 +1,574 @@
+use anyhow::{anyhow, Result};
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+use sqlx::PgPool;
+
+use activitypub_base::{
+    ApUser, ApUserRepository, BlockedDomain, FederationRepository, Follower, FollowerStatus,
+    FollowingStatus, RemoteActor,
+};
+
+// ── PostgresFederationRepository ─────────────────────────────────────────────
+
+pub struct PostgresFederationRepository {
+    pool: PgPool,
+}
+
+impl PostgresFederationRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+fn status_str(s: &FollowerStatus) -> &'static str {
+    match s {
+        FollowerStatus::Pending => "pending",
+        FollowerStatus::Accepted => "accepted",
+        FollowerStatus::Rejected => "rejected",
+    }
+}
+fn str_status(s: &str) -> FollowerStatus {
+    match s {
+        "accepted" => FollowerStatus::Accepted,
+        "rejected" => FollowerStatus::Rejected,
+        _ => FollowerStatus::Pending,
+    }
+}
+
+fn map_remote_actor(
+    url: String,
+    handle: String,
+    inbox_url: String,
+    shared_inbox_url: Option<String>,
+    display_name: Option<String>,
+    avatar_url: Option<String>,
+    outbox_url: Option<String>,
+) -> RemoteActor {
+    RemoteActor {
+        url,
+        handle,
+        inbox_url,
+        shared_inbox_url,
+        display_name,
+        avatar_url,
+        outbox_url,
+    }
+}
+
+#[async_trait]
+impl FederationRepository for PostgresFederationRepository {
+    async fn add_follower(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+        status: FollowerStatus,
+        follow_activity_id: &str,
+    ) -> Result<()> {
+        sqlx::query(
+            "INSERT INTO federation_followers(local_user_id,remote_actor_url,status,follow_activity_id)
+             VALUES($1,$2,$3,$4)
+             ON CONFLICT(local_user_id,remote_actor_url) DO UPDATE
+             SET status=EXCLUDED.status, follow_activity_id=EXCLUDED.follow_activity_id"
+        )
+        .bind(local_user_id).bind(remote_actor_url).bind(status_str(&status)).bind(follow_activity_id)
+        .execute(&self.pool).await.map_err(|e| anyhow!(e)).map(|_| ())
+    }
+
+    async fn get_follower_follow_activity_id(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+    ) -> Result<Option<String>> {
+        sqlx::query_scalar::<_, String>(
+            "SELECT follow_activity_id FROM federation_followers WHERE local_user_id=$1 AND remote_actor_url=$2"
+        ).bind(local_user_id).bind(remote_actor_url).fetch_optional(&self.pool).await.map_err(|e| anyhow!(e))
+    }
+
+    async fn remove_follower(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+    ) -> Result<()> {
+        sqlx::query(
+            "DELETE FROM federation_followers WHERE local_user_id=$1 AND remote_actor_url=$2",
+        )
+        .bind(local_user_id)
+        .bind(remote_actor_url)
+        .execute(&self.pool)
+        .await
+        .map_err(|e| anyhow!(e))
+        .map(|_| ())
+    }
+
+    async fn get_followers(&self, local_user_id: uuid::Uuid) -> Result<Vec<Follower>> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            remote_actor_url: String,
+            status: String,
+            handle: String,
+            inbox_url: String,
+            shared_inbox_url: Option<String>,
+            display_name: Option<String>,
+            avatar_url: Option<String>,
+            outbox_url: Option<String>,
+        }
+        sqlx::query_as::<_, Row>(
+            "SELECT f.remote_actor_url, f.status, COALESCE(r.handle,'') AS handle,
+             COALESCE(r.inbox_url,'') AS inbox_url, r.shared_inbox_url, r.display_name, r.avatar_url, r.outbox_url
+             FROM federation_followers f
+             LEFT JOIN remote_actors r ON r.url=f.remote_actor_url
+             WHERE f.local_user_id=$1 AND f.status='accepted'"
+        ).bind(local_user_id).fetch_all(&self.pool).await.map_err(|e| anyhow!(e)).map(|rows| rows.into_iter().map(|r| Follower {
+            actor: map_remote_actor(r.remote_actor_url, r.handle, r.inbox_url, r.shared_inbox_url, r.display_name, r.avatar_url, r.outbox_url),
+            status: str_status(&r.status),
+        }).collect())
+    }
+
+    async fn get_followers_page(
+        &self,
+        local_user_id: uuid::Uuid,
+        offset: u32,
+        limit: usize,
+    ) -> Result<Vec<Follower>> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            remote_actor_url: String,
+            status: String,
+            handle: String,
+            inbox_url: String,
+            shared_inbox_url: Option<String>,
+            display_name: Option<String>,
+            avatar_url: Option<String>,
+            outbox_url: Option<String>,
+        }
+        sqlx::query_as::<_, Row>(
+            "SELECT f.remote_actor_url, f.status, COALESCE(r.handle,'') AS handle,
+             COALESCE(r.inbox_url,'') AS inbox_url, r.shared_inbox_url, r.display_name, r.avatar_url, r.outbox_url
+             FROM federation_followers f
+             LEFT JOIN remote_actors r ON r.url=f.remote_actor_url
+             WHERE f.local_user_id=$1 AND f.status='accepted'
+             ORDER BY f.created_at DESC LIMIT $2 OFFSET $3"
+        ).bind(local_user_id).bind(limit as i64).bind(offset as i64).fetch_all(&self.pool).await.map_err(|e| anyhow!(e)).map(|rows| rows.into_iter().map(|r| Follower {
+            actor: map_remote_actor(r.remote_actor_url, r.handle, r.inbox_url, r.shared_inbox_url, r.display_name, r.avatar_url, r.outbox_url),
+            status: str_status(&r.status),
+        }).collect())
+    }
+
+    async fn count_followers(&self, local_user_id: uuid::Uuid) -> Result<usize> {
+        let n: i64 = sqlx::query_scalar(
+            "SELECT COUNT(*) FROM federation_followers WHERE local_user_id=$1 AND status='accepted'"
+        ).bind(local_user_id).fetch_one(&self.pool).await.map_err(|e| anyhow!(e))?;
+        Ok(n as usize)
+    }
+
+    async fn get_pending_followers(&self, local_user_id: uuid::Uuid) -> Result<Vec<RemoteActor>> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            remote_actor_url: String,
+            handle: String,
+            inbox_url: String,
+            shared_inbox_url: Option<String>,
+            display_name: Option<String>,
+            avatar_url: Option<String>,
+            outbox_url: Option<String>,
+        }
+        sqlx::query_as::<_, Row>(
+            "SELECT f.remote_actor_url, COALESCE(r.handle,'') AS handle,
+             COALESCE(r.inbox_url,'') AS inbox_url, r.shared_inbox_url, r.display_name, r.avatar_url, r.outbox_url
+             FROM federation_followers f
+             LEFT JOIN remote_actors r ON r.url=f.remote_actor_url
+             WHERE f.local_user_id=$1 AND f.status='pending'"
+        ).bind(local_user_id).fetch_all(&self.pool).await.map_err(|e| anyhow!(e)).map(|rows| rows.into_iter().map(|r|
+            map_remote_actor(r.remote_actor_url, r.handle, r.inbox_url, r.shared_inbox_url, r.display_name, r.avatar_url, r.outbox_url)
+        ).collect())
+    }
+
+    async fn update_follower_status(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+        status: FollowerStatus,
+    ) -> Result<()> {
+        sqlx::query("UPDATE federation_followers SET status=$3 WHERE local_user_id=$1 AND remote_actor_url=$2")
+            .bind(local_user_id).bind(remote_actor_url).bind(status_str(&status))
+            .execute(&self.pool).await.map_err(|e| anyhow!(e)).map(|_| ())
+    }
+
+    async fn add_following(
+        &self,
+        local_user_id: uuid::Uuid,
+        actor: RemoteActor,
+        follow_activity_id: &str,
+    ) -> Result<()> {
+        self.upsert_remote_actor(actor.clone()).await?;
+        sqlx::query(
+            "INSERT INTO federation_following(local_user_id,remote_actor_url,follow_activity_id,outbox_url)
+             VALUES($1,$2,$3,$4)
+             ON CONFLICT(local_user_id,remote_actor_url) DO UPDATE
+             SET follow_activity_id=EXCLUDED.follow_activity_id"
+        )
+        .bind(local_user_id).bind(&actor.url).bind(follow_activity_id).bind(&actor.outbox_url)
+        .execute(&self.pool).await.map_err(|e| anyhow!(e)).map(|_| ())
+    }
+
+    async fn get_follow_activity_id(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+    ) -> Result<Option<String>> {
+        sqlx::query_scalar::<_, String>(
+            "SELECT follow_activity_id FROM federation_following WHERE local_user_id=$1 AND remote_actor_url=$2"
+        ).bind(local_user_id).bind(remote_actor_url).fetch_optional(&self.pool).await.map_err(|e| anyhow!(e))
+    }
+
+    async fn remove_following(&self, local_user_id: uuid::Uuid, actor_url: &str) -> Result<()> {
+        sqlx::query(
+            "DELETE FROM federation_following WHERE local_user_id=$1 AND remote_actor_url=$2",
+        )
+        .bind(local_user_id)
+        .bind(actor_url)
+        .execute(&self.pool)
+        .await
+        .map_err(|e| anyhow!(e))
+        .map(|_| ())
+    }
+
+    async fn get_following(&self, local_user_id: uuid::Uuid) -> Result<Vec<RemoteActor>> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            remote_actor_url: String,
+            handle: String,
+            inbox_url: String,
+            shared_inbox_url: Option<String>,
+            display_name: Option<String>,
+            avatar_url: Option<String>,
+            outbox_url: Option<String>,
+        }
+        sqlx::query_as::<_, Row>(
+            "SELECT f.remote_actor_url, COALESCE(r.handle,'') AS handle,
+             COALESCE(r.inbox_url,'') AS inbox_url, r.shared_inbox_url, r.display_name, r.avatar_url, r.outbox_url
+             FROM federation_following f
+             LEFT JOIN remote_actors r ON r.url=f.remote_actor_url
+             WHERE f.local_user_id=$1"
+        ).bind(local_user_id).fetch_all(&self.pool).await.map_err(|e| anyhow!(e)).map(|rows| rows.into_iter().map(|r|
+            map_remote_actor(r.remote_actor_url, r.handle, r.inbox_url, r.shared_inbox_url, r.display_name, r.avatar_url, r.outbox_url)
+        ).collect())
+    }
+
+    async fn get_following_page(
+        &self,
+        local_user_id: uuid::Uuid,
+        offset: u32,
+        limit: usize,
+    ) -> Result<Vec<RemoteActor>> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            remote_actor_url: String,
+            handle: String,
+            inbox_url: String,
+            shared_inbox_url: Option<String>,
+            display_name: Option<String>,
+            avatar_url: Option<String>,
+            outbox_url: Option<String>,
+        }
+        sqlx::query_as::<_, Row>(
+            "SELECT f.remote_actor_url, COALESCE(r.handle,'') AS handle,
+             COALESCE(r.inbox_url,'') AS inbox_url, r.shared_inbox_url, r.display_name, r.avatar_url, r.outbox_url
+             FROM federation_following f
+             LEFT JOIN remote_actors r ON r.url=f.remote_actor_url
+             WHERE f.local_user_id=$1 AND f.status='accepted'
+             ORDER BY f.created_at DESC LIMIT $2 OFFSET $3"
+        ).bind(local_user_id).bind(limit as i64).bind(offset as i64).fetch_all(&self.pool).await.map_err(|e| anyhow!(e)).map(|rows| rows.into_iter().map(|r|
+            map_remote_actor(r.remote_actor_url, r.handle, r.inbox_url, r.shared_inbox_url, r.display_name, r.avatar_url, r.outbox_url)
+        ).collect())
+    }
+
+    async fn count_following(&self, local_user_id: uuid::Uuid) -> Result<usize> {
+        let n: i64 =
+            sqlx::query_scalar("SELECT COUNT(*) FROM federation_following WHERE local_user_id=$1 AND status='accepted'")
+                .bind(local_user_id)
+                .fetch_one(&self.pool)
+                .await
+                .map_err(|e| anyhow!(e))?;
+        Ok(n as usize)
+    }
+
+    async fn update_following_status(
+        &self,
+        _local_user_id: uuid::Uuid,
+        _remote_actor_url: &str,
+        _status: FollowingStatus,
+    ) -> Result<()> {
+        Ok(())
+    }
+
+    async fn get_following_outbox_url(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+    ) -> Result<Option<String>> {
+        sqlx::query_scalar::<_, String>(
+            "SELECT outbox_url FROM federation_following WHERE local_user_id=$1 AND remote_actor_url=$2"
+        ).bind(local_user_id).bind(remote_actor_url).fetch_optional(&self.pool).await.map_err(|e| anyhow!(e))
+    }
+
+    async fn upsert_remote_actor(&self, actor: RemoteActor) -> Result<()> {
+        sqlx::query(
+            "INSERT INTO remote_actors(url,handle,display_name,inbox_url,shared_inbox_url,public_key,avatar_url,outbox_url,last_fetched_at)
+             VALUES($1,$2,$3,$4,$5,'',$6,$7,NOW())
+             ON CONFLICT(url) DO UPDATE SET handle=EXCLUDED.handle,display_name=EXCLUDED.display_name,
+             inbox_url=EXCLUDED.inbox_url,shared_inbox_url=EXCLUDED.shared_inbox_url,
+             avatar_url=EXCLUDED.avatar_url,outbox_url=EXCLUDED.outbox_url,last_fetched_at=NOW()"
+        )
+        .bind(&actor.url).bind(&actor.handle).bind(&actor.display_name)
+        .bind(&actor.inbox_url).bind(&actor.shared_inbox_url)
+        .bind(&actor.avatar_url).bind(&actor.outbox_url)
+        .execute(&self.pool).await.map_err(|e| anyhow!(e)).map(|_| ())
+    }
+
+    async fn get_remote_actor(&self, actor_url: &str) -> Result<Option<RemoteActor>> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            url: String,
+            handle: String,
+            inbox_url: String,
+            shared_inbox_url: Option<String>,
+            display_name: Option<String>,
+            avatar_url: Option<String>,
+            outbox_url: Option<String>,
+        }
+        sqlx::query_as::<_, Row>(
+            "SELECT url,handle,inbox_url,shared_inbox_url,display_name,avatar_url,outbox_url FROM remote_actors WHERE url=$1"
+        ).bind(actor_url).fetch_optional(&self.pool).await.map_err(|e| anyhow!(e)).map(|o| o.map(|r|
+            map_remote_actor(r.url, r.handle, r.inbox_url, r.shared_inbox_url, r.display_name, r.avatar_url, r.outbox_url)
+        ))
+    }
+
+    async fn get_local_actor_keypair(
+        &self,
+        user_id: uuid::Uuid,
+    ) -> Result<Option<(String, String)>> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            public_key: Option<String>,
+            private_key: Option<String>,
+        }
+        let row = sqlx::query_as::<_, Row>(
+            "SELECT public_key, private_key FROM users WHERE id=$1 AND local=true",
+        )
+        .bind(user_id)
+        .fetch_optional(&self.pool)
+        .await
+        .map_err(|e| anyhow!(e))?;
+        Ok(row.and_then(|r| match (r.public_key, r.private_key) {
+            (Some(pub_k), Some(priv_k)) => Some((pub_k, priv_k)),
+            _ => None,
+        }))
+    }
+
+    async fn save_local_actor_keypair(
+        &self,
+        user_id: uuid::Uuid,
+        public_key: String,
+        private_key: String,
+    ) -> Result<()> {
+        sqlx::query("UPDATE users SET public_key=$2, private_key=$3, updated_at=NOW() WHERE id=$1")
+            .bind(user_id)
+            .bind(&public_key)
+            .bind(&private_key)
+            .execute(&self.pool)
+            .await
+            .map_err(|e| anyhow!(e))
+            .map(|_| ())
+    }
+
+    async fn add_announce(
+        &self,
+        activity_id: &str,
+        object_url: &str,
+        actor_url: &str,
+        announced_at: DateTime<Utc>,
+    ) -> Result<()> {
+        sqlx::query(
+            "INSERT INTO federation_announces(activity_id,object_url,actor_url,announced_at)
+             VALUES($1,$2,$3,$4) ON CONFLICT(activity_id) DO NOTHING",
+        )
+        .bind(activity_id)
+        .bind(object_url)
+        .bind(actor_url)
+        .bind(announced_at)
+        .execute(&self.pool)
+        .await
+        .map_err(|e| anyhow!(e))
+        .map(|_| ())
+    }
+
+    async fn count_announces(&self, object_url: &str) -> Result<usize> {
+        let n: i64 =
+            sqlx::query_scalar("SELECT COUNT(*) FROM federation_announces WHERE object_url=$1")
+                .bind(object_url)
+                .fetch_one(&self.pool)
+                .await
+                .map_err(|e| anyhow!(e))?;
+        Ok(n as usize)
+    }
+
+    async fn add_blocked_domain(&self, domain: &str, reason: Option<&str>) -> Result<()> {
+        sqlx::query(
+            "INSERT INTO federation_blocked_domains(domain,reason) VALUES($1,$2) ON CONFLICT(domain) DO NOTHING"
+        ).bind(domain).bind(reason).execute(&self.pool).await.map_err(|e| anyhow!(e)).map(|_| ())
+    }
+
+    async fn remove_blocked_domain(&self, domain: &str) -> Result<()> {
+        sqlx::query("DELETE FROM federation_blocked_domains WHERE domain=$1")
+            .bind(domain)
+            .execute(&self.pool)
+            .await
+            .map_err(|e| anyhow!(e))
+            .map(|_| ())
+    }
+
+    async fn get_blocked_domains(&self) -> Result<Vec<BlockedDomain>> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            domain: String,
+            reason: Option<String>,
+            blocked_at: DateTime<Utc>,
+        }
+        sqlx::query_as::<_, Row>(
+            "SELECT domain,reason,blocked_at FROM federation_blocked_domains ORDER BY domain",
+        )
+        .fetch_all(&self.pool)
+        .await
+        .map_err(|e| anyhow!(e))
+        .map(|rows| {
+            rows.into_iter()
+                .map(|r| BlockedDomain {
+                    domain: r.domain,
+                    reason: r.reason,
+                    blocked_at: r.blocked_at.to_rfc3339(),
+                })
+                .collect()
+        })
+    }
+
+    async fn is_domain_blocked(&self, domain: &str) -> Result<bool> {
+        let n: i64 =
+            sqlx::query_scalar("SELECT COUNT(*) FROM federation_blocked_domains WHERE domain=$1")
+                .bind(domain)
+                .fetch_one(&self.pool)
+                .await
+                .map_err(|e| anyhow!(e))?;
+        Ok(n > 0)
+    }
+
+    async fn add_blocked_actor(&self, local_user_id: uuid::Uuid, actor_url: &str) -> Result<()> {
+        sqlx::query(
+            "INSERT INTO federation_blocked_actors(local_user_id,actor_url) VALUES($1,$2) ON CONFLICT DO NOTHING"
+        ).bind(local_user_id).bind(actor_url).execute(&self.pool).await.map_err(|e| anyhow!(e)).map(|_| ())
+    }
+
+    async fn remove_blocked_actor(&self, local_user_id: uuid::Uuid, actor_url: &str) -> Result<()> {
+        sqlx::query("DELETE FROM federation_blocked_actors WHERE local_user_id=$1 AND actor_url=$2")
+            .bind(local_user_id)
+            .bind(actor_url)
+            .execute(&self.pool)
+            .await
+            .map_err(|e| anyhow!(e))
+            .map(|_| ())
+    }
+
+    async fn get_blocked_actors(&self, local_user_id: uuid::Uuid) -> Result<Vec<String>> {
+        sqlx::query_scalar::<_, String>(
+            "SELECT actor_url FROM federation_blocked_actors WHERE local_user_id=$1 ORDER BY created_at DESC"
+        ).bind(local_user_id).fetch_all(&self.pool).await.map_err(|e| anyhow!(e))
+    }
+
+    async fn is_actor_blocked(&self, local_user_id: uuid::Uuid, actor_url: &str) -> Result<bool> {
+        let n: i64 = sqlx::query_scalar(
+            "SELECT COUNT(*) FROM federation_blocked_actors WHERE local_user_id=$1 AND actor_url=$2"
+        ).bind(local_user_id).bind(actor_url).fetch_one(&self.pool).await.map_err(|e| anyhow!(e))?;
+        Ok(n > 0)
+    }
+}
+
+// ── PostgresApUserRepository ──────────────────────────────────────────────────
+
+pub struct PostgresApUserRepository {
+    pool: PgPool,
+    base_url: String,
+}
+
+impl PostgresApUserRepository {
+    pub fn new(pool: PgPool, base_url: String) -> Self {
+        Self { pool, base_url }
+    }
+
+    fn row_to_ap_user(
+        &self,
+        id: uuid::Uuid,
+        username: String,
+        bio: Option<String>,
+        avatar_url: Option<String>,
+    ) -> ApUser {
+        let profile_url = url::Url::parse(&format!("{}/users/{}", self.base_url, username)).ok();
+        let avatar_url = avatar_url.and_then(|u| url::Url::parse(&u).ok());
+        ApUser {
+            id,
+            username,
+            bio,
+            avatar_url,
+            banner_url: None,
+            also_known_as: None,
+            profile_url,
+            attachment: vec![],
+        }
+    }
+}
+
+#[async_trait]
+impl ApUserRepository for PostgresApUserRepository {
+    async fn find_by_id(&self, id: uuid::Uuid) -> Result<Option<ApUser>> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            id: uuid::Uuid,
+            username: String,
+            bio: Option<String>,
+            avatar_url: Option<String>,
+        }
+        let row = sqlx::query_as::<_, Row>(
+            "SELECT id,username,bio,avatar_url FROM users WHERE id=$1 AND local=true",
+        )
+        .bind(id)
+        .fetch_optional(&self.pool)
+        .await
+        .map_err(|e| anyhow!(e))?;
+        Ok(row.map(|r| self.row_to_ap_user(r.id, r.username, r.bio, r.avatar_url)))
+    }
+
+    async fn find_by_username(&self, username: &str) -> Result<Option<ApUser>> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            id: uuid::Uuid,
+            username: String,
+            bio: Option<String>,
+            avatar_url: Option<String>,
+        }
+        let row = sqlx::query_as::<_, Row>(
+            "SELECT id,username,bio,avatar_url FROM users WHERE username=$1 AND local=true",
+        )
+        .bind(username)
+        .fetch_optional(&self.pool)
+        .await
+        .map_err(|e| anyhow!(e))?;
+        Ok(row.map(|r| self.row_to_ap_user(r.id, r.username, r.bio, r.avatar_url)))
+    }
+
+    async fn count_users(&self) -> Result<usize> {
+        let n: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM users WHERE local=true")
+            .fetch_one(&self.pool)
+            .await
+            .map_err(|e| anyhow!(e))?;
+        Ok(n as usize)
+    }
+}

crates/adapters/postgres-search/Cargo.toml

@@ -0,0 +1,17 @@
+[package]
+name = "postgres-search"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+domain      = { workspace = true }
+postgres    = { workspace = true }
+sqlx        = { workspace = true }
+uuid        = { workspace = true }
+chrono      = { workspace = true }
+async-trait = { workspace = true }
+
+[dev-dependencies]
+tokio    = { workspace = true, features = ["full"] }
+sqlx     = { workspace = true, features = ["migrate"] }
+postgres = { workspace = true }

crates/adapters/postgres-search/src/lib.rs

@@ -0,0 +1,372 @@
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+
+use domain::{
+    errors::DomainError,
+    models::{
+        feed::{FeedEntry, PageParams, Paginated},
+        thought::{Thought, Visibility},
+        user::User,
+    },
+    ports::SearchPort,
+    value_objects::{Content, Email, PasswordHash, ThoughtId, UserId, Username},
+};
+use postgres::user::{UserRow, USER_SELECT};
+use sqlx::PgPool;
+
+pub struct PgSearchRepository {
+    pool: PgPool,
+}
+impl PgSearchRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[derive(sqlx::FromRow)]
+struct FeedRow {
+    thought_id: uuid::Uuid,
+    t_user_id: uuid::Uuid,
+    content: String,
+    in_reply_to_id: Option<uuid::Uuid>,
+    visibility: String,
+    content_warning: Option<String>,
+    sensitive: bool,
+    t_local: bool,
+    thought_created_at: DateTime<Utc>,
+    updated_at: Option<DateTime<Utc>>,
+    author_id: uuid::Uuid,
+    username: String,
+    email: String,
+    password_hash: String,
+    display_name: Option<String>,
+    bio: Option<String>,
+    avatar_url: Option<String>,
+    header_url: Option<String>,
+    custom_css: Option<String>,
+    author_local: bool,
+    author_created_at: DateTime<Utc>,
+    author_updated_at: DateTime<Utc>,
+    like_count: i64,
+    boost_count: i64,
+    reply_count: i64,
+    liked_by_viewer: bool,
+    boosted_by_viewer: bool,
+}
+
+fn feed_select(viewer: Option<uuid::Uuid>) -> String {
+    let viewer_checks = match viewer {
+        Some(uid) => format!(
+            "EXISTS(SELECT 1 FROM likes  WHERE user_id='{uid}' AND thought_id=t.id) AS liked_by_viewer,\n\
+             EXISTS(SELECT 1 FROM boosts WHERE user_id='{uid}' AND thought_id=t.id) AS boosted_by_viewer"
+        ),
+        None => "false AS liked_by_viewer, false AS boosted_by_viewer".to_string(),
+    };
+    format!(
+        "\n    SELECT\n\
+         t.id AS thought_id, t.user_id AS t_user_id, t.content,\n\
+         t.in_reply_to_id,\n\
+         t.visibility, t.content_warning, t.sensitive, t.local AS t_local,\n\
+         t.created_at AS thought_created_at, t.updated_at,\n\
+         u.id AS author_id, u.username, u.email, u.password_hash,\n\
+         u.display_name, u.bio, u.avatar_url, u.header_url, u.custom_css,\n\
+         u.local AS author_local,\n\
+         u.created_at AS author_created_at, u.updated_at AS author_updated_at,\n\
+         (SELECT COUNT(*) FROM likes  l WHERE l.thought_id=t.id) AS like_count,\n\
+         (SELECT COUNT(*) FROM boosts b WHERE b.thought_id=t.id) AS boost_count,\n\
+         (SELECT COUNT(*) FROM thoughts r WHERE r.in_reply_to_id=t.id) AS reply_count,\n\
+         {viewer_checks}\n\
+     FROM thoughts t JOIN users u ON u.id=t.user_id"
+    )
+}
+
+fn row_to_entry(r: FeedRow, viewer: Option<uuid::Uuid>) -> Result<FeedEntry, DomainError> {
+    let thought = Thought {
+        id: ThoughtId::from_uuid(r.thought_id),
+        user_id: UserId::from_uuid(r.t_user_id),
+        content: Content::new_remote(r.content),
+        in_reply_to_id: r.in_reply_to_id.map(ThoughtId::from_uuid),
+        visibility: Visibility::from_db_str(&r.visibility)?,
+        content_warning: r.content_warning,
+        sensitive: r.sensitive,
+        local: r.t_local,
+        created_at: r.thought_created_at,
+        updated_at: r.updated_at,
+    };
+    let author = User {
+        id: UserId::from_uuid(r.author_id),
+        username: Username::from_trusted(r.username),
+        email: Email::from_trusted(r.email),
+        password_hash: PasswordHash(r.password_hash),
+        display_name: r.display_name,
+        bio: r.bio,
+        avatar_url: r.avatar_url,
+        header_url: r.header_url,
+        custom_css: r.custom_css,
+        local: r.author_local,
+        created_at: r.author_created_at,
+        updated_at: r.author_updated_at,
+    };
+    Ok(FeedEntry {
+        thought,
+        author,
+        stats: domain::models::feed::EngagementStats {
+            like_count: r.like_count,
+            boost_count: r.boost_count,
+            reply_count: r.reply_count,
+        },
+        viewer: viewer.map(|_| domain::models::feed::ViewerContext {
+            liked: r.liked_by_viewer,
+            boosted: r.boosted_by_viewer,
+        }),
+    })
+}
+
+#[async_trait]
+impl SearchPort for PgSearchRepository {
+    async fn search_thoughts(
+        &self,
+        query: &str,
+        page: &PageParams,
+        viewer_id: Option<&UserId>,
+    ) -> Result<Paginated<FeedEntry>, DomainError> {
+        let viewer = viewer_id.map(|v| v.as_uuid());
+        let select = feed_select(viewer);
+
+        let total: i64 = sqlx::query_scalar(
+            "SELECT COUNT(*) FROM thoughts t
+             WHERE t.content % $1 AND t.visibility='public'",
+        )
+        .bind(query)
+        .fetch_one(&self.pool)
+        .await
+        .map_err(|e| DomainError::Internal(e.to_string()))?;
+
+        let sql = format!(
+            "{select}
+             WHERE t.content % $1 AND t.visibility='public'
+             ORDER BY similarity(t.content, $1) DESC
+             LIMIT $2 OFFSET $3"
+        );
+        let rows = sqlx::query_as::<_, FeedRow>(&sql)
+            .bind(query)
+            .bind(page.limit())
+            .bind(page.offset())
+            .fetch_all(&self.pool)
+            .await
+            .map_err(|e| DomainError::Internal(e.to_string()))?;
+
+        Ok(Paginated {
+            items: rows
+                .into_iter()
+                .map(|r| row_to_entry(r, viewer))
+                .collect::<Result<Vec<_>, _>>()?,
+            total,
+            page: page.page,
+            per_page: page.per_page,
+        })
+    }
+
+    async fn search_users(
+        &self,
+        query: &str,
+        page: &PageParams,
+    ) -> Result<Paginated<User>, DomainError> {
+        let total: i64 = sqlx::query_scalar(
+            "SELECT COUNT(*) FROM users u
+             WHERE u.local=true AND (u.username % $1 OR u.display_name % $1)",
+        )
+        .bind(query)
+        .fetch_one(&self.pool)
+        .await
+        .map_err(|e| DomainError::Internal(e.to_string()))?;
+
+        let sql = format!(
+            "{USER_SELECT}
+             WHERE local=true AND (username % $1 OR display_name % $1)
+             ORDER BY similarity(username || ' ' || COALESCE(display_name,''), $1) DESC
+             LIMIT $2 OFFSET $3"
+        );
+        let rows = sqlx::query_as::<_, UserRow>(&sql)
+            .bind(query)
+            .bind(page.limit())
+            .bind(page.offset())
+            .fetch_all(&self.pool)
+            .await
+            .map_err(|e| DomainError::Internal(e.to_string()))?;
+
+        Ok(Paginated {
+            items: rows.into_iter().map(User::from).collect(),
+            total,
+            page: page.page,
+            per_page: page.per_page,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use domain::{
+        models::{
+            thought::{Thought, Visibility},
+            user::User,
+        },
+        ports::{SearchPort, ThoughtRepository, UserWriter},
+        value_objects::*,
+    };
+
+    async fn seed_thought(pool: &sqlx::PgPool, username: &str, content: &str) -> (User, Thought) {
+        use postgres::{thought::PgThoughtRepository, user::PgUserRepository};
+        let urepo = PgUserRepository::new(pool.clone());
+        let trepo = PgThoughtRepository::new(pool.clone());
+        let u = User::new_local(
+            UserId::new(),
+            Username::new(username).unwrap(),
+            Email::new(format!("{username}@ex.com")).unwrap(),
+            PasswordHash("h".into()),
+        );
+        urepo.save(&u).await.unwrap();
+        let t = Thought::new_local(
+            ThoughtId::new(),
+            u.id.clone(),
+            Content::new_local(content).unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        );
+        trepo.save(&t).await.unwrap();
+        (u, t)
+    }
+
+    #[sqlx::test(migrations = "../postgres/migrations")]
+    async fn search_thoughts_finds_by_keyword(pool: sqlx::PgPool) {
+        seed_thought(&pool, "alice", "hello world").await;
+        seed_thought(&pool, "bob", "goodbye universe").await;
+        let repo = PgSearchRepository::new(pool);
+        let result = repo
+            .search_thoughts(
+                "hello world",
+                &PageParams {
+                    page: 1,
+                    per_page: 20,
+                },
+                None,
+            )
+            .await
+            .unwrap();
+        assert_eq!(result.total, 1);
+        assert_eq!(result.items[0].thought.content.as_str(), "hello world");
+    }
+
+    #[sqlx::test(migrations = "../postgres/migrations")]
+    async fn search_users_finds_by_username(pool: sqlx::PgPool) {
+        use postgres::user::PgUserRepository;
+        let urepo = PgUserRepository::new(pool.clone());
+        let alice = User::new_local(
+            UserId::new(),
+            Username::new("alice_search").unwrap(),
+            Email::new("alice@ex.com").unwrap(),
+            PasswordHash("h".into()),
+        );
+        urepo.save(&alice).await.unwrap();
+        let repo = PgSearchRepository::new(pool);
+        let result = repo
+            .search_users(
+                "alice",
+                &PageParams {
+                    page: 1,
+                    per_page: 20,
+                },
+            )
+            .await
+            .unwrap();
+        assert!(!result.items.is_empty());
+        assert!(result
+            .items
+            .iter()
+            .any(|u| u.username.as_str() == "alice_search"));
+    }
+
+    #[sqlx::test(migrations = "../postgres/migrations")]
+    async fn search_thoughts_returns_empty_for_no_match(pool: sqlx::PgPool) {
+        seed_thought(&pool, "alice", "hello world").await;
+        let repo = PgSearchRepository::new(pool);
+        let result = repo
+            .search_thoughts(
+                "zzzzzzzzz",
+                &PageParams {
+                    page: 1,
+                    per_page: 20,
+                },
+                None,
+            )
+            .await
+            .unwrap();
+        assert_eq!(result.total, 0);
+    }
+
+    #[sqlx::test(migrations = "../postgres/migrations")]
+    async fn search_thoughts_viewer_context(pool: sqlx::PgPool) {
+        use domain::models::social::Like;
+        use domain::ports::{LikeRepository, UserWriter};
+        use domain::value_objects::LikeId;
+        use postgres::{like::PgLikeRepository, user::PgUserRepository};
+
+        let (alice, thought) = seed_thought(&pool, "alice", "hello world").await;
+
+        // alice likes her own thought
+        let like_repo = PgLikeRepository::new(pool.clone());
+        like_repo
+            .save(&Like {
+                id: LikeId::new(),
+                user_id: alice.id.clone(),
+                thought_id: thought.id.clone(),
+                ap_id: None,
+                created_at: chrono::Utc::now(),
+            })
+            .await
+            .unwrap();
+
+        let repo = PgSearchRepository::new(pool);
+
+        // with viewer — should see liked = true
+        let authed = repo
+            .search_thoughts(
+                "hello",
+                &PageParams {
+                    page: 1,
+                    per_page: 20,
+                },
+                Some(&alice.id),
+            )
+            .await
+            .unwrap();
+        assert_eq!(authed.items.len(), 1);
+        let ctx = authed.items[0]
+            .viewer
+            .as_ref()
+            .expect("viewer context present");
+        assert!(ctx.liked, "alice should see the thought as liked");
+        assert!(!ctx.boosted);
+
+        // without viewer — viewer should be None
+        let anon = repo
+            .search_thoughts(
+                "hello",
+                &PageParams {
+                    page: 1,
+                    per_page: 20,
+                },
+                None,
+            )
+            .await
+            .unwrap();
+        assert_eq!(anon.items.len(), 1);
+        assert!(
+            anon.items[0].viewer.is_none(),
+            "anonymous request has no viewer context"
+        );
+    }
+}

crates/adapters/postgres/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "postgres"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+domain           = { workspace = true }
+activitypub-base = { workspace = true }
+event-payload    = { workspace = true }
+sqlx             = { workspace = true }
+uuid        = { workspace = true }
+serde_json  = { workspace = true }
+chrono      = { workspace = true }
+async-trait = { workspace = true }
+thiserror   = { workspace = true }
+tracing     = { workspace = true }
+url         = { workspace = true }
+
+[dev-dependencies]
+tokio = { workspace = true, features = ["full"] }
+sqlx  = { workspace = true, features = ["migrate"] }

crates/adapters/postgres/migrations/001_initial_schema.sql

@@ -0,0 +1,55 @@
+CREATE EXTENSION IF NOT EXISTS "pgcrypto";
+
+CREATE TABLE IF NOT EXISTS users (
+    id           UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    username     VARCHAR(32)  NOT NULL UNIQUE,
+    email        VARCHAR(255) NOT NULL UNIQUE,
+    password_hash TEXT        NOT NULL,
+    display_name VARCHAR(50),
+    bio          VARCHAR(160),
+    avatar_url   TEXT,
+    header_url   TEXT,
+    custom_css   TEXT,
+    created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    updated_at   TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE TABLE IF NOT EXISTS thoughts (
+    id         UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id    UUID        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    content    VARCHAR(128) NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE TABLE IF NOT EXISTS follows (
+    follower_id  UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    following_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    PRIMARY KEY (follower_id, following_id)
+);
+
+CREATE TABLE IF NOT EXISTS top_friends (
+    user_id   UUID     NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    friend_id UUID     NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    position  SMALLINT NOT NULL,
+    PRIMARY KEY (user_id, friend_id),
+    UNIQUE (user_id, position)
+);
+
+CREATE TABLE IF NOT EXISTS tags (
+    id   SERIAL PRIMARY KEY,
+    name VARCHAR(50) NOT NULL UNIQUE
+);
+
+CREATE TABLE IF NOT EXISTS thought_tags (
+    thought_id UUID    NOT NULL REFERENCES thoughts(id) ON DELETE CASCADE,
+    tag_id     INTEGER NOT NULL REFERENCES tags(id) ON DELETE CASCADE,
+    PRIMARY KEY (thought_id, tag_id)
+);
+
+CREATE TABLE IF NOT EXISTS api_keys (
+    id         UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id    UUID        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    key_hash   TEXT        NOT NULL UNIQUE,
+    name       VARCHAR(50) NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);

crates/adapters/postgres/migrations/002_federation_columns.sql

@@ -0,0 +1,21 @@
+ALTER TABLE users
+    ADD COLUMN IF NOT EXISTS ap_id        TEXT UNIQUE,
+    ADD COLUMN IF NOT EXISTS inbox_url    TEXT,
+    ADD COLUMN IF NOT EXISTS public_key   TEXT,
+    ADD COLUMN IF NOT EXISTS private_key  TEXT,
+    ADD COLUMN IF NOT EXISTS local        BOOLEAN NOT NULL DEFAULT true;
+
+ALTER TABLE thoughts
+    ADD COLUMN IF NOT EXISTS in_reply_to_id  UUID REFERENCES thoughts(id),
+    ADD COLUMN IF NOT EXISTS in_reply_to_url TEXT,
+    ADD COLUMN IF NOT EXISTS ap_id           TEXT UNIQUE,
+    ADD COLUMN IF NOT EXISTS visibility      TEXT NOT NULL DEFAULT 'public',
+    ADD COLUMN IF NOT EXISTS content_warning TEXT,
+    ADD COLUMN IF NOT EXISTS sensitive       BOOLEAN NOT NULL DEFAULT false,
+    ADD COLUMN IF NOT EXISTS local           BOOLEAN NOT NULL DEFAULT true,
+    ADD COLUMN IF NOT EXISTS updated_at      TIMESTAMPTZ;
+
+ALTER TABLE follows
+    ADD COLUMN IF NOT EXISTS state      TEXT        NOT NULL DEFAULT 'accepted',
+    ADD COLUMN IF NOT EXISTS ap_id      TEXT,
+    ADD COLUMN IF NOT EXISTS created_at TIMESTAMPTZ NOT NULL DEFAULT NOW();

crates/adapters/postgres/migrations/003_new_tables.sql

@@ -0,0 +1,49 @@
+CREATE TABLE IF NOT EXISTS likes (
+    id         UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id    UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    thought_id UUID NOT NULL REFERENCES thoughts(id) ON DELETE CASCADE,
+    ap_id      TEXT UNIQUE,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    UNIQUE (user_id, thought_id)
+);
+
+CREATE TABLE IF NOT EXISTS boosts (
+    id         UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id    UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    thought_id UUID NOT NULL REFERENCES thoughts(id) ON DELETE CASCADE,
+    ap_id      TEXT UNIQUE,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    UNIQUE (user_id, thought_id)
+);
+
+CREATE TABLE IF NOT EXISTS blocks (
+    blocker_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    blocked_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    PRIMARY KEY (blocker_id, blocked_id)
+);
+
+CREATE TABLE IF NOT EXISTS remote_actors (
+    url              TEXT PRIMARY KEY,
+    handle           TEXT NOT NULL,
+    display_name     TEXT,
+    inbox_url        TEXT NOT NULL,
+    shared_inbox_url TEXT,
+    public_key       TEXT NOT NULL,
+    last_fetched_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE TABLE IF NOT EXISTS notifications (
+    id           UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    user_id      UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    type         TEXT NOT NULL,
+    from_user_id UUID REFERENCES users(id) ON DELETE SET NULL,
+    thought_id   UUID REFERENCES thoughts(id) ON DELETE CASCADE,
+    read         BOOLEAN NOT NULL DEFAULT false,
+    created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE INDEX IF NOT EXISTS idx_thoughts_user_id ON thoughts(user_id);
+CREATE INDEX IF NOT EXISTS idx_thoughts_created_at ON thoughts(created_at DESC);
+CREATE INDEX IF NOT EXISTS idx_follows_following_id ON follows(following_id);
+CREATE INDEX IF NOT EXISTS idx_notifications_user_id ON notifications(user_id, read);

crates/adapters/postgres/migrations/004_search_indexes.sql

@@ -0,0 +1,11 @@
+CREATE EXTENSION IF NOT EXISTS pg_trgm;
+
+CREATE INDEX IF NOT EXISTS idx_thoughts_content_trgm
+    ON thoughts USING GIN(content gin_trgm_ops);
+
+CREATE INDEX IF NOT EXISTS idx_users_username_trgm
+    ON users USING GIN(username gin_trgm_ops);
+
+CREATE INDEX IF NOT EXISTS idx_users_display_name_trgm
+    ON users USING GIN(display_name gin_trgm_ops)
+    WHERE display_name IS NOT NULL;

crates/adapters/postgres/migrations/005_federation_tables.sql

@@ -0,0 +1,54 @@
+-- Add avatar_url and outbox_url to remote_actors (FederationRepository::RemoteActor needs them)
+ALTER TABLE remote_actors
+    ADD COLUMN IF NOT EXISTS avatar_url  TEXT,
+    ADD COLUMN IF NOT EXISTS outbox_url  TEXT;
+
+-- Federation followers: remote actors following local users
+CREATE TABLE IF NOT EXISTS federation_followers (
+    id               UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    local_user_id    UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    remote_actor_url TEXT NOT NULL,
+    status           TEXT NOT NULL DEFAULT 'pending',
+    follow_activity_id TEXT NOT NULL,
+    created_at       TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    UNIQUE (local_user_id, remote_actor_url)
+);
+
+-- Federation following: local users following remote actors
+CREATE TABLE IF NOT EXISTS federation_following (
+    id               UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    local_user_id    UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    remote_actor_url TEXT NOT NULL,
+    follow_activity_id TEXT NOT NULL,
+    outbox_url       TEXT,
+    created_at       TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    UNIQUE (local_user_id, remote_actor_url)
+);
+
+-- Announces (boosts of remote objects via AP)
+CREATE TABLE IF NOT EXISTS federation_announces (
+    id           UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    activity_id  TEXT NOT NULL UNIQUE,
+    object_url   TEXT NOT NULL,
+    actor_url    TEXT NOT NULL,
+    announced_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Blocked domains (instance-level)
+CREATE TABLE IF NOT EXISTS federation_blocked_domains (
+    domain     TEXT PRIMARY KEY,
+    reason     TEXT,
+    blocked_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+-- Blocked actors (per local user)
+CREATE TABLE IF NOT EXISTS federation_blocked_actors (
+    local_user_id UUID NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+    actor_url     TEXT NOT NULL,
+    created_at    TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    PRIMARY KEY (local_user_id, actor_url)
+);
+
+CREATE INDEX IF NOT EXISTS idx_fed_followers_user   ON federation_followers(local_user_id);
+CREATE INDEX IF NOT EXISTS idx_fed_following_user   ON federation_following(local_user_id);
+CREATE INDEX IF NOT EXISTS idx_fed_announces_object ON federation_announces(object_url);

crates/adapters/postgres/migrations/006_remote_actor_connections.sql

@@ -0,0 +1,13 @@
+CREATE TABLE remote_actor_connections (
+    id                     UUID        PRIMARY KEY DEFAULT gen_random_uuid(),
+    actor_url              TEXT        NOT NULL,
+    connection_type        TEXT        NOT NULL,
+    page                   INT         NOT NULL,
+    connected_actor_url    TEXT        NOT NULL,
+    connected_handle       TEXT        NOT NULL,
+    connected_display_name TEXT,
+    connected_avatar_url   TEXT,
+    fetched_at             TIMESTAMPTZ NOT NULL DEFAULT NOW(),
+    UNIQUE(actor_url, connection_type, page, connected_actor_url)
+);
+CREATE INDEX ON remote_actor_connections(actor_url, connection_type, page, fetched_at);

crates/adapters/postgres/migrations/007_content_text.sql

@@ -0,0 +1,3 @@
+-- Remote ActivityPub posts can exceed 128 characters.
+-- The 128-char limit is enforced at the application layer for local posts only.
+ALTER TABLE thoughts ALTER COLUMN content TYPE TEXT;

crates/adapters/postgres/migrations/008_rename_notifications_type.sql

@@ -0,0 +1 @@
+ALTER TABLE notifications RENAME COLUMN "type" TO notification_type;

crates/adapters/postgres/migrations/009_failed_events.sql

@@ -0,0 +1,15 @@
+CREATE TABLE failed_events (
+    id           UUID        NOT NULL DEFAULT gen_random_uuid(),
+    event_type   TEXT        NOT NULL,
+    payload      JSONB       NOT NULL,
+    failed_at    TIMESTAMPTZ NOT NULL DEFAULT now(),
+    retry_at     TIMESTAMPTZ NOT NULL,
+    retry_count  INT         NOT NULL DEFAULT 0,
+    last_error   TEXT        NOT NULL,
+
+    CONSTRAINT failed_events_pkey PRIMARY KEY (id)
+);
+
+CREATE INDEX failed_events_due_idx
+    ON failed_events (retry_at)
+    WHERE retry_count < 3;

crates/adapters/postgres/migrations/010_fix_reply_fk_on_delete.sql

@@ -0,0 +1,11 @@
+-- Change in_reply_to_id FK from RESTRICT (default) to SET NULL.
+-- Previously, deleting a thought that had replies raised a FK violation.
+-- With SET NULL, deleting a thought orphans its replies (they survive but
+-- lose their parent reference), which is the correct semantic for a
+-- threaded social app.
+ALTER TABLE thoughts
+    DROP CONSTRAINT IF EXISTS thoughts_in_reply_to_id_fkey;
+
+ALTER TABLE thoughts
+    ADD CONSTRAINT thoughts_in_reply_to_id_fkey
+    FOREIGN KEY (in_reply_to_id) REFERENCES thoughts(id) ON DELETE SET NULL;

crates/adapters/postgres/migrations/011_outbox_events.sql

@@ -0,0 +1,10 @@
+CREATE TABLE outbox_events (
+    seq          BIGSERIAL   PRIMARY KEY,
+    aggregate_id UUID        NOT NULL,
+    event_type   TEXT        NOT NULL,
+    payload      JSONB       NOT NULL,
+    created_at   TIMESTAMPTZ NOT NULL DEFAULT now(),
+    delivered    BOOLEAN     NOT NULL DEFAULT false,
+    delivered_at TIMESTAMPTZ
+);
+CREATE INDEX outbox_events_pending_idx ON outbox_events (seq) WHERE delivered = false;

crates/adapters/postgres/src/activitypub.rs

@@ -0,0 +1,406 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+
+const MAX_REMOTE_CONTENT_CHARS: usize = 500;
+const THOUGHTS_PATH_PREFIX: &str = "/thoughts/";
+use chrono::{DateTime, Utc};
+use sqlx::PgPool;
+
+use activitypub_base::{ActivityPubRepository, ActorApUrls, OutboxEntry};
+use domain::{
+    errors::DomainError,
+    models::thought::{Thought, Visibility},
+    value_objects::{Content, ThoughtId, UserId, Username},
+};
+
+pub struct PgActivityPubRepository {
+    pool: PgPool,
+}
+
+impl PgActivityPubRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[async_trait]
+impl ActivityPubRepository for PgActivityPubRepository {
+    async fn outbox_entries_for_actor(
+        &self,
+        user_id: &UserId,
+    ) -> Result<Vec<OutboxEntry>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            id: uuid::Uuid,
+            user_id: uuid::Uuid,
+            content: String,
+            created_at: DateTime<Utc>,
+            in_reply_to_id: Option<uuid::Uuid>,
+            content_warning: Option<String>,
+            sensitive: bool,
+            username: String,
+            updated_at: Option<DateTime<Utc>>,
+        }
+        sqlx::query_as::<_, Row>(
+            "SELECT t.id, t.user_id, t.content, t.created_at, t.in_reply_to_id, t.content_warning, t.sensitive, u.username, t.updated_at
+             FROM thoughts t JOIN users u ON u.id=t.user_id
+             WHERE t.user_id=$1 AND t.local=true AND t.visibility='public'
+             ORDER BY t.created_at DESC",
+        )
+        .bind(user_id.as_uuid())
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()
+        .map(|rows| {
+            rows.into_iter()
+                .map(|r| OutboxEntry {
+                    thought: Thought {
+                        id: ThoughtId::from_uuid(r.id),
+                        user_id: UserId::from_uuid(r.user_id),
+                        content: Content::new_remote(r.content),
+                        in_reply_to_id: r.in_reply_to_id.map(ThoughtId::from_uuid),
+                        visibility: Visibility::Public,
+                        content_warning: r.content_warning,
+                        sensitive: r.sensitive,
+                        local: true,
+                        created_at: r.created_at,
+                        updated_at: r.updated_at,
+                    },
+                    author_username: Username::from_trusted(r.username),
+                })
+                .collect()
+        })
+    }
+
+    async fn outbox_page_for_actor(
+        &self,
+        user_id: &UserId,
+        before: Option<DateTime<Utc>>,
+        limit: usize,
+    ) -> Result<Vec<OutboxEntry>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            id: uuid::Uuid,
+            user_id: uuid::Uuid,
+            content: String,
+            created_at: DateTime<Utc>,
+            in_reply_to_id: Option<uuid::Uuid>,
+            content_warning: Option<String>,
+            sensitive: bool,
+            username: String,
+            updated_at: Option<DateTime<Utc>>,
+        }
+        let rows = if let Some(before) = before {
+            sqlx::query_as::<_, Row>(
+                "SELECT t.id, t.user_id, t.content, t.created_at, t.in_reply_to_id, t.content_warning, t.sensitive, u.username, t.updated_at
+                 FROM thoughts t JOIN users u ON u.id=t.user_id
+                 WHERE t.user_id=$1 AND t.local=true AND t.visibility='public' AND t.created_at < $2
+                 ORDER BY t.created_at DESC LIMIT $3",
+            )
+            .bind(user_id.as_uuid())
+            .bind(before)
+            .bind(limit as i64)
+            .fetch_all(&self.pool)
+            .await
+        } else {
+            sqlx::query_as::<_, Row>(
+                "SELECT t.id, t.user_id, t.content, t.created_at, t.in_reply_to_id, t.content_warning, t.sensitive, u.username, t.updated_at
+                 FROM thoughts t JOIN users u ON u.id=t.user_id
+                 WHERE t.user_id=$1 AND t.local=true AND t.visibility='public'
+                 ORDER BY t.created_at DESC LIMIT $2",
+            )
+            .bind(user_id.as_uuid())
+            .bind(limit as i64)
+            .fetch_all(&self.pool)
+            .await
+        }
+        .into_domain()?;
+
+        Ok(rows
+            .into_iter()
+            .map(|r| OutboxEntry {
+                thought: Thought {
+                    id: ThoughtId::from_uuid(r.id),
+                    user_id: UserId::from_uuid(r.user_id),
+                    content: Content::new_remote(r.content),
+                    in_reply_to_id: r.in_reply_to_id.map(ThoughtId::from_uuid),
+                    visibility: Visibility::Public,
+                    content_warning: r.content_warning,
+                    sensitive: r.sensitive,
+                    local: true,
+                    created_at: r.created_at,
+                    updated_at: r.updated_at,
+                },
+                author_username: Username::from_trusted(r.username),
+            })
+            .collect())
+    }
+
+    async fn find_remote_actor_id(
+        &self,
+        actor_ap_url: &str,
+    ) -> Result<Option<UserId>, DomainError> {
+        sqlx::query_scalar::<_, uuid::Uuid>("SELECT id FROM users WHERE ap_id=$1")
+            .bind(actor_ap_url)
+            .fetch_optional(&self.pool)
+            .await
+            .into_domain()
+            .map(|o| o.map(UserId::from_uuid))
+    }
+
+    async fn intern_remote_actor(&self, actor_ap_url: &str) -> Result<UserId, DomainError> {
+        if let Some(id) = self.find_remote_actor_id(actor_ap_url).await? {
+            return Ok(id);
+        }
+        let new_id = uuid::Uuid::new_v4();
+        // Use the last path segment as username (e.g. /users/alice → "alice").
+        // Falls back to a random short id for long segments (e.g. UUID-based actor URLs).
+        // username column is VARCHAR(32).
+        let last_seg = url::Url::parse(actor_ap_url)
+            .ok()
+            .and_then(|u| {
+                u.path_segments()
+                    .and_then(|mut s| s.next_back().map(|s| s.to_string()))
+            })
+            .unwrap_or_default();
+        let handle = if last_seg.is_empty() {
+            format!("remote_{}", &new_id.to_string()[..13])
+        } else if last_seg.len() <= 32 {
+            last_seg
+        } else {
+            format!("remote_{}", &new_id.to_string()[..13])
+        };
+        sqlx::query(
+            "INSERT INTO users(id,username,email,password_hash,local,ap_id,created_at,updated_at)
+             VALUES($1,$2,$3,'',false,$4,NOW(),NOW()) ON CONFLICT(ap_id) DO NOTHING",
+        )
+        .bind(new_id)
+        .bind(&handle)
+        .bind(format!("{}@remote", new_id))
+        .bind(actor_ap_url)
+        .execute(&self.pool)
+        .await
+        .into_domain()?;
+        // Re-fetch to get whichever id won the race
+        self.find_remote_actor_id(actor_ap_url)
+            .await?
+            .ok_or_else(|| {
+                DomainError::Internal(
+                    "intern_remote_actor: insert succeeded but row not found".into(),
+                )
+            })
+    }
+
+    async fn update_remote_actor_display(
+        &self,
+        user_id: &UserId,
+        display_name: Option<&str>,
+        avatar_url: Option<&str>,
+    ) -> Result<(), DomainError> {
+        sqlx::query(
+            "UPDATE users SET display_name=$1, avatar_url=$2, updated_at=NOW()
+             WHERE id=$3 AND local=false",
+        )
+        .bind(display_name)
+        .bind(avatar_url)
+        .bind(user_id.as_uuid())
+        .execute(&self.pool)
+        .await
+        .into_domain()
+        .map(|_| ())
+    }
+
+    async fn accept_note(
+        &self,
+        ap_id: &str,
+        author_id: &UserId,
+        content: &str,
+        published: DateTime<Utc>,
+        sensitive: bool,
+        content_warning: Option<String>,
+        visibility: &str,
+        in_reply_to: Option<&str>,
+    ) -> Result<ThoughtId, DomainError> {
+        let capped: String = content.chars().take(MAX_REMOTE_CONTENT_CHARS).collect();
+        let (in_reply_to_id, in_reply_to_url) = match in_reply_to {
+            Some(url) => {
+                // If the parent is a local thought, extract its UUID for in_reply_to_id.
+                let local_uuid = url::Url::parse(url).ok().and_then(|u| {
+                    u.path()
+                        .strip_prefix(THOUGHTS_PATH_PREFIX)
+                        .and_then(|s| s.split('/').next())
+                        .and_then(|s| uuid::Uuid::parse_str(s).ok())
+                });
+                (local_uuid, Some(url.to_string()))
+            }
+            None => (None, None),
+        };
+        sqlx::query(
+            "INSERT INTO thoughts(id,user_id,content,ap_id,visibility,sensitive,local,content_warning,created_at,in_reply_to_id,in_reply_to_url)
+             VALUES($1,$2,$3,$4,$8,$5,false,$6,$7,$9,$10) ON CONFLICT(ap_id) DO NOTHING",
+        )
+        .bind(uuid::Uuid::new_v4())
+        .bind(author_id.as_uuid())
+        .bind(&capped)
+        .bind(ap_id)
+        .bind(sensitive)
+        .bind(content_warning)
+        .bind(published)
+        .bind(visibility)
+        .bind(in_reply_to_id)
+        .bind(&in_reply_to_url)
+        .execute(&self.pool)
+        .await
+        .into_domain()?;
+
+        // SELECT the id — works whether the INSERT was a no-op or not (idempotent).
+        let row: (uuid::Uuid,) =
+            sqlx::query_as("SELECT id FROM thoughts WHERE ap_id=$1")
+                .bind(ap_id)
+                .fetch_one(&self.pool)
+                .await
+                .into_domain()?;
+        Ok(ThoughtId::from_uuid(row.0))
+    }
+
+    async fn apply_note_update(&self, ap_id: &str, new_content: &str) -> Result<(), DomainError> {
+        let capped: String = new_content.chars().take(MAX_REMOTE_CONTENT_CHARS).collect();
+        sqlx::query(
+            "UPDATE thoughts SET content=$2,updated_at=NOW() WHERE ap_id=$1 AND local=false",
+        )
+        .bind(ap_id)
+        .bind(&capped)
+        .execute(&self.pool)
+        .await
+        .into_domain()
+        .map(|_| ())
+    }
+
+    async fn retract_note(&self, ap_id: &str) -> Result<(), DomainError> {
+        sqlx::query("DELETE FROM thoughts WHERE ap_id=$1 AND local=false")
+            .bind(ap_id)
+            .execute(&self.pool)
+            .await
+            .into_domain()
+            .map(|_| ())
+    }
+
+    async fn retract_actor_notes(&self, actor_ap_url: &str) -> Result<(), DomainError> {
+        sqlx::query(
+            "DELETE FROM thoughts WHERE local=false AND user_id=(SELECT id FROM users WHERE ap_id=$1)",
+        )
+        .bind(actor_ap_url)
+        .execute(&self.pool)
+        .await
+        .into_domain()
+        .map(|_| ())
+    }
+
+    async fn count_local_notes(&self) -> Result<u64, DomainError> {
+        let n: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM thoughts WHERE local=true")
+            .fetch_one(&self.pool)
+            .await
+            .into_domain()?;
+        Ok(n as u64)
+    }
+
+    async fn get_thought_ap_id(
+        &self,
+        thought_id: &ThoughtId,
+    ) -> Result<Option<String>, DomainError> {
+        sqlx::query_scalar::<_, String>(
+            "SELECT ap_id FROM thoughts WHERE id = $1 AND ap_id IS NOT NULL",
+        )
+        .bind(thought_id.as_uuid())
+        .fetch_optional(&self.pool)
+        .await
+        .into_domain()
+    }
+
+    async fn get_actor_ap_urls(
+        &self,
+        user_id: &UserId,
+    ) -> Result<Option<ActorApUrls>, DomainError> {
+        sqlx::query_as::<_, (String, String)>(
+            "SELECT ap_id, inbox_url FROM users \
+             WHERE id = $1 AND ap_id IS NOT NULL AND inbox_url IS NOT NULL",
+        )
+        .bind(user_id.as_uuid())
+        .fetch_optional(&self.pool)
+        .await
+        .into_domain()
+        .map(|opt| opt.map(|(ap_id, inbox_url)| ActorApUrls { ap_id, inbox_url }))
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use activitypub_base::ActivityPubRepository;
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn intern_remote_actor_is_idempotent(pool: sqlx::PgPool) {
+        let repo = PgActivityPubRepository::new(pool);
+        let url = "https://mastodon.social/users/alice";
+        let id1 = repo.intern_remote_actor(url).await.unwrap();
+        let id2 = repo.intern_remote_actor(url).await.unwrap();
+        assert_eq!(id1, id2);
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn accept_and_retract_note(pool: sqlx::PgPool) {
+        let repo = PgActivityPubRepository::new(pool);
+        let actor_url = "https://remote.example/users/bob";
+        let ap_id = "https://remote.example/notes/1";
+        let author = repo.intern_remote_actor(actor_url).await.unwrap();
+        repo.accept_note(
+            ap_id,
+            &author,
+            "hello from remote",
+            chrono::Utc::now(),
+            false,
+            None,
+            "public",
+            None,
+        )
+        .await
+        .unwrap();
+        repo.retract_note(ap_id).await.unwrap();
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn count_local_notes_excludes_remote(pool: sqlx::PgPool) {
+        let repo = PgActivityPubRepository::new(pool);
+        assert_eq!(repo.count_local_notes().await.unwrap(), 0);
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn accept_note_returns_thought_id(pool: sqlx::PgPool) {
+        let repo = PgActivityPubRepository::new(pool.clone());
+        let actor_user_id = repo
+            .intern_remote_actor("https://remote.example/users/alice")
+            .await
+            .unwrap();
+
+        let thought_id = repo
+            .accept_note(
+                "https://remote.example/notes/1",
+                &actor_user_id,
+                "Hello #rust world",
+                chrono::Utc::now(),
+                false,
+                None,
+                "public",
+                None,
+            )
+            .await
+            .unwrap();
+
+        let row: (uuid::Uuid,) = sqlx::query_as("SELECT id FROM thoughts WHERE ap_id=$1")
+            .bind("https://remote.example/notes/1")
+            .fetch_one(&pool)
+            .await
+            .unwrap();
+        assert_eq!(thought_id.as_uuid(), row.0);
+    }
+}

crates/adapters/postgres/src/api_key.rs

@@ -0,0 +1,142 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+use domain::{
+    errors::DomainError,
+    models::api_key::ApiKey,
+    ports::ApiKeyRepository,
+    value_objects::{ApiKeyId, UserId},
+};
+use sqlx::PgPool;
+
+pub struct PgApiKeyRepository {
+    pool: PgPool,
+}
+impl PgApiKeyRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[async_trait]
+impl ApiKeyRepository for PgApiKeyRepository {
+    async fn save(&self, k: &ApiKey) -> Result<(), DomainError> {
+        sqlx::query(
+            "INSERT INTO api_keys(id,user_id,key_hash,name,created_at) VALUES($1,$2,$3,$4,$5)",
+        )
+        .bind(k.id.as_uuid())
+        .bind(k.user_id.as_uuid())
+        .bind(&k.key_hash)
+        .bind(&k.name)
+        .bind(k.created_at)
+        .execute(&self.pool)
+        .await
+        .into_domain()
+        .map(|_| ())
+    }
+
+    async fn find_by_hash(&self, hash: &str) -> Result<Option<ApiKey>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            id: uuid::Uuid,
+            user_id: uuid::Uuid,
+            key_hash: String,
+            name: String,
+            created_at: DateTime<Utc>,
+        }
+        sqlx::query_as::<_, Row>(
+            "SELECT id,user_id,key_hash,name,created_at FROM api_keys WHERE key_hash=$1",
+        )
+        .bind(hash)
+        .fetch_optional(&self.pool)
+        .await
+        .into_domain()
+        .map(|o| {
+            o.map(|r| ApiKey {
+                id: ApiKeyId::from_uuid(r.id),
+                user_id: UserId::from_uuid(r.user_id),
+                key_hash: r.key_hash,
+                name: r.name,
+                created_at: r.created_at,
+            })
+        })
+    }
+
+    async fn list_for_user(&self, user_id: &UserId) -> Result<Vec<ApiKey>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            id: uuid::Uuid,
+            user_id: uuid::Uuid,
+            key_hash: String,
+            name: String,
+            created_at: DateTime<Utc>,
+        }
+        sqlx::query_as::<_, Row>("SELECT id,user_id,key_hash,name,created_at FROM api_keys WHERE user_id=$1 ORDER BY created_at DESC")
+            .bind(user_id.as_uuid()).fetch_all(&self.pool).await
+            .into_domain()
+            .map(|rows| rows.into_iter().map(|r| ApiKey { id: ApiKeyId::from_uuid(r.id), user_id: UserId::from_uuid(r.user_id), key_hash: r.key_hash, name: r.name, created_at: r.created_at }).collect())
+    }
+
+    async fn delete(&self, id: &ApiKeyId, user_id: &UserId) -> Result<(), DomainError> {
+        sqlx::query("DELETE FROM api_keys WHERE id=$1 AND user_id=$2")
+            .bind(id.as_uuid())
+            .bind(user_id.as_uuid())
+            .execute(&self.pool)
+            .await
+            .into_domain()
+            .map(|_| ())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::user::PgUserRepository;
+    use chrono::Utc;
+    use domain::ports::UserWriter;
+    use domain::{models::user::User, value_objects::*};
+
+    async fn seed_user(pool: &sqlx::PgPool) -> User {
+        let repo = PgUserRepository::new(pool.clone());
+        let u = User::new_local(
+            UserId::new(),
+            Username::new("alice").unwrap(),
+            Email::new("alice@ex.com").unwrap(),
+            PasswordHash("h".into()),
+        );
+        repo.save(&u).await.unwrap();
+        u
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn save_and_find_by_hash(pool: sqlx::PgPool) {
+        let user = seed_user(&pool).await;
+        let repo = PgApiKeyRepository::new(pool);
+        let key = ApiKey {
+            id: ApiKeyId::new(),
+            user_id: user.id.clone(),
+            key_hash: "abc123".into(),
+            name: "test".into(),
+            created_at: Utc::now(),
+        };
+        repo.save(&key).await.unwrap();
+        let found = repo.find_by_hash("abc123").await.unwrap().unwrap();
+        assert_eq!(found.name, "test");
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn delete_key(pool: sqlx::PgPool) {
+        let user = seed_user(&pool).await;
+        let repo = PgApiKeyRepository::new(pool);
+        let key = ApiKey {
+            id: ApiKeyId::new(),
+            user_id: user.id.clone(),
+            key_hash: "def456".into(),
+            name: "key2".into(),
+            created_at: Utc::now(),
+        };
+        repo.save(&key).await.unwrap();
+        repo.delete(&key.id, &user.id).await.unwrap();
+        assert!(repo.find_by_hash("def456").await.unwrap().is_none());
+    }
+}

crates/adapters/postgres/src/block.rs

@@ -0,0 +1,90 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use domain::{
+    errors::DomainError, models::social::Block, ports::BlockRepository, value_objects::UserId,
+};
+use sqlx::PgPool;
+
+pub struct PgBlockRepository {
+    pool: PgPool,
+}
+impl PgBlockRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[async_trait]
+impl BlockRepository for PgBlockRepository {
+    async fn save(&self, b: &Block) -> Result<(), DomainError> {
+        sqlx::query(
+            "INSERT INTO blocks(blocker_id,blocked_id,created_at) VALUES($1,$2,$3) ON CONFLICT DO NOTHING"
+        )
+        .bind(b.blocker_id.as_uuid())
+        .bind(b.blocked_id.as_uuid())
+        .bind(b.created_at)
+        .execute(&self.pool)
+        .await
+        .into_domain()
+        .map(|_| ())
+    }
+
+    async fn delete(&self, blocker_id: &UserId, blocked_id: &UserId) -> Result<(), DomainError> {
+        sqlx::query("DELETE FROM blocks WHERE blocker_id=$1 AND blocked_id=$2")
+            .bind(blocker_id.as_uuid())
+            .bind(blocked_id.as_uuid())
+            .execute(&self.pool)
+            .await
+            .into_domain()
+            .map(|_| ())
+    }
+
+    async fn exists(&self, blocker_id: &UserId, blocked_id: &UserId) -> Result<bool, DomainError> {
+        let count: i64 =
+            sqlx::query_scalar("SELECT COUNT(*) FROM blocks WHERE blocker_id=$1 AND blocked_id=$2")
+                .bind(blocker_id.as_uuid())
+                .bind(blocked_id.as_uuid())
+                .fetch_one(&self.pool)
+                .await
+                .into_domain()?;
+        Ok(count > 0)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::test_helpers::seed_user;
+    use chrono::Utc;
+    use domain::value_objects::*;
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn block_exists(pool: sqlx::PgPool) {
+        let alice = seed_user(&pool, "alice", "alice@ex.com").await;
+        let bob = seed_user(&pool, "bob", "bob@ex.com").await;
+        let repo = PgBlockRepository::new(pool);
+        let block = Block {
+            blocker_id: alice.id.clone(),
+            blocked_id: bob.id.clone(),
+            created_at: Utc::now(),
+        };
+        repo.save(&block).await.unwrap();
+        assert!(repo.exists(&alice.id, &bob.id).await.unwrap());
+        assert!(!repo.exists(&bob.id, &alice.id).await.unwrap());
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn unblock(pool: sqlx::PgPool) {
+        let alice = seed_user(&pool, "alice", "alice@ex.com").await;
+        let bob = seed_user(&pool, "bob", "bob@ex.com").await;
+        let repo = PgBlockRepository::new(pool);
+        let block = Block {
+            blocker_id: alice.id.clone(),
+            blocked_id: bob.id.clone(),
+            created_at: Utc::now(),
+        };
+        repo.save(&block).await.unwrap();
+        repo.delete(&alice.id, &bob.id).await.unwrap();
+        assert!(!repo.exists(&alice.id, &bob.id).await.unwrap());
+    }
+}

crates/adapters/postgres/src/boost.rs

@@ -0,0 +1,110 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+use domain::{
+    errors::DomainError,
+    models::social::Boost,
+    ports::BoostRepository,
+    value_objects::{BoostId, ThoughtId, UserId},
+};
+use sqlx::PgPool;
+
+pub struct PgBoostRepository {
+    pool: PgPool,
+}
+impl PgBoostRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[async_trait]
+impl BoostRepository for PgBoostRepository {
+    async fn save(&self, b: &Boost) -> Result<(), DomainError> {
+        sqlx::query(
+            "INSERT INTO boosts(id,user_id,thought_id,ap_id,created_at) VALUES($1,$2,$3,$4,$5) ON CONFLICT(user_id,thought_id) DO NOTHING"
+        )
+        .bind(b.id.as_uuid()).bind(b.user_id.as_uuid()).bind(b.thought_id.as_uuid()).bind(&b.ap_id).bind(b.created_at)
+        .execute(&self.pool).await.into_domain().map(|_| ())
+    }
+
+    async fn delete(&self, user_id: &UserId, thought_id: &ThoughtId) -> Result<(), DomainError> {
+        let r = sqlx::query("DELETE FROM boosts WHERE user_id=$1 AND thought_id=$2")
+            .bind(user_id.as_uuid())
+            .bind(thought_id.as_uuid())
+            .execute(&self.pool)
+            .await
+            .into_domain()?;
+        if r.rows_affected() == 0 {
+            return Err(DomainError::NotFound);
+        }
+        Ok(())
+    }
+
+    async fn find(
+        &self,
+        user_id: &UserId,
+        thought_id: &ThoughtId,
+    ) -> Result<Option<Boost>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            id: uuid::Uuid,
+            user_id: uuid::Uuid,
+            thought_id: uuid::Uuid,
+            ap_id: Option<String>,
+            created_at: DateTime<Utc>,
+        }
+        sqlx::query_as::<_, Row>("SELECT id,user_id,thought_id,ap_id,created_at FROM boosts WHERE user_id=$1 AND thought_id=$2")
+            .bind(user_id.as_uuid()).bind(thought_id.as_uuid())
+            .fetch_optional(&self.pool).await
+            .into_domain()
+            .map(|o| o.map(|r| Boost { id: BoostId::from_uuid(r.id), user_id: UserId::from_uuid(r.user_id), thought_id: ThoughtId::from_uuid(r.thought_id), ap_id: r.ap_id, created_at: r.created_at }))
+    }
+
+    async fn count_for_thought(&self, thought_id: &ThoughtId) -> Result<i64, DomainError> {
+        sqlx::query_scalar("SELECT COUNT(*) FROM boosts WHERE thought_id=$1")
+            .bind(thought_id.as_uuid())
+            .fetch_one(&self.pool)
+            .await
+            .into_domain()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::test_helpers::seed_user_and_thought;
+    use chrono::Utc;
+    use domain::value_objects::*;
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn boost_and_count(pool: sqlx::PgPool) {
+        let (user, thought) = seed_user_and_thought(&pool).await;
+        let repo = PgBoostRepository::new(pool);
+        let boost = Boost {
+            id: BoostId::new(),
+            user_id: user.id.clone(),
+            thought_id: thought.id.clone(),
+            ap_id: None,
+            created_at: Utc::now(),
+        };
+        repo.save(&boost).await.unwrap();
+        assert_eq!(repo.count_for_thought(&thought.id).await.unwrap(), 1);
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn unboost(pool: sqlx::PgPool) {
+        let (user, thought) = seed_user_and_thought(&pool).await;
+        let repo = PgBoostRepository::new(pool);
+        let boost = Boost {
+            id: BoostId::new(),
+            user_id: user.id.clone(),
+            thought_id: thought.id.clone(),
+            ap_id: None,
+            created_at: Utc::now(),
+        };
+        repo.save(&boost).await.unwrap();
+        repo.delete(&user.id, &thought.id).await.unwrap();
+        assert_eq!(repo.count_for_thought(&thought.id).await.unwrap(), 0);
+    }
+}

crates/adapters/postgres/src/db_error.rs

@@ -0,0 +1,20 @@
+use domain::errors::DomainError;
+
+pub(crate) trait IntoDbResult<T> {
+    fn into_domain(self) -> Result<T, DomainError>;
+}
+
+impl<T> IntoDbResult<T> for Result<T, sqlx::Error> {
+    fn into_domain(self) -> Result<T, DomainError> {
+        self.map_err(|e| {
+            if let sqlx::Error::Database(ref db) = e {
+                if db.code().as_deref() == Some("23505") {
+                    return DomainError::Conflict(
+                        db.constraint().unwrap_or("conflict").to_string(),
+                    );
+                }
+            }
+            DomainError::Internal(e.to_string())
+        })
+    }
+}

crates/adapters/postgres/src/engagement.rs

@@ -0,0 +1,83 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use domain::{
+    errors::DomainError,
+    models::feed::{EngagementStats, ViewerContext},
+    ports::EngagementRepository,
+    value_objects::{ThoughtId, UserId},
+};
+use sqlx::PgPool;
+use std::collections::HashMap;
+
+pub struct PgEngagementRepository {
+    pool: PgPool,
+}
+
+impl PgEngagementRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[async_trait]
+impl EngagementRepository for PgEngagementRepository {
+    async fn get_for_thoughts(
+        &self,
+        thought_ids: &[ThoughtId],
+        viewer_id: Option<&UserId>,
+    ) -> Result<HashMap<ThoughtId, (EngagementStats, Option<ViewerContext>)>, DomainError> {
+        if thought_ids.is_empty() {
+            return Ok(HashMap::new());
+        }
+
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            thought_id: uuid::Uuid,
+            like_count: i64,
+            boost_count: i64,
+            reply_count: i64,
+            liked_by_viewer: bool,
+            boosted_by_viewer: bool,
+        }
+
+        let ids: Vec<uuid::Uuid> = thought_ids.iter().map(|t| t.as_uuid()).collect();
+        let viewer_uuid: Option<uuid::Uuid> = viewer_id.map(|v| v.as_uuid());
+
+        let rows = sqlx::query_as::<_, Row>(
+            "SELECT
+                t.id AS thought_id,
+                COUNT(DISTINCT l.user_id) AS like_count,
+                COUNT(DISTINCT b.user_id) AS boost_count,
+                COUNT(DISTINCT r.id) AS reply_count,
+                COALESCE(BOOL_OR(l.user_id = $2), false) AS liked_by_viewer,
+                COALESCE(BOOL_OR(b.user_id = $2), false) AS boosted_by_viewer
+             FROM thoughts t
+             LEFT JOIN likes l ON l.thought_id = t.id
+             LEFT JOIN boosts b ON b.thought_id = t.id
+             LEFT JOIN thoughts r ON r.in_reply_to_id = t.id
+             WHERE t.id = ANY($1)
+             GROUP BY t.id",
+        )
+        .bind(&ids[..])
+        .bind(viewer_uuid)
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()?;
+
+        let mut result = HashMap::new();
+        for row in rows {
+            let tid = ThoughtId::from_uuid(row.thought_id);
+            let stats = EngagementStats {
+                like_count: row.like_count,
+                boost_count: row.boost_count,
+                reply_count: row.reply_count,
+            };
+            let viewer = viewer_id.map(|_| ViewerContext {
+                liked: row.liked_by_viewer,
+                boosted: row.boosted_by_viewer,
+            });
+            result.insert(tid, (stats, viewer));
+        }
+        Ok(result)
+    }
+}

crates/adapters/postgres/src/failed_event.rs

@@ -0,0 +1,105 @@
+use chrono::{DateTime, Utc};
+use sqlx::PgPool;
+
+/// How many times a failed event is retried by the DLQ processor.
+pub const DLQ_MAX_RETRIES: i32 = 3;
+/// Quarantine period for the first DLQ retry (seconds). Doubles each retry.
+pub const DLQ_INITIAL_BACKOFF_SECS: i64 = 300; // 5 minutes
+/// How often the DLQ processor polls for due retries (seconds).
+pub const DLQ_POLL_INTERVAL_SECS: u64 = 60;
+
+#[derive(sqlx::FromRow)]
+pub struct FailedEvent {
+    pub id: uuid::Uuid,
+    pub event_type: String,
+    pub payload: serde_json::Value,
+    pub failed_at: DateTime<Utc>,
+    pub retry_at: DateTime<Utc>,
+    pub retry_count: i32,
+    pub last_error: String,
+}
+
+pub struct PgFailedEventStore {
+    pool: PgPool,
+}
+
+impl PgFailedEventStore {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+
+    /// Insert a newly exhausted event into the DLQ.
+    pub async fn insert(
+        &self,
+        event_type: &str,
+        payload: &serde_json::Value,
+        last_error: &str,
+    ) -> Result<(), sqlx::Error> {
+        let retry_at = Utc::now() + chrono::Duration::seconds(DLQ_INITIAL_BACKOFF_SECS);
+        sqlx::query(
+            "INSERT INTO failed_events \
+             (event_type, payload, retry_at, last_error) \
+             VALUES ($1, $2, $3, $4)",
+        )
+        .bind(event_type)
+        .bind(payload)
+        .bind(retry_at)
+        .bind(last_error)
+        .execute(&self.pool)
+        .await?;
+        Ok(())
+    }
+
+    /// Fetch all events due for retry (retry_at <= now, retry_count < DLQ_MAX_RETRIES).
+    pub async fn poll_due(&self) -> Result<Vec<FailedEvent>, sqlx::Error> {
+        sqlx::query_as::<_, FailedEvent>(
+            "SELECT id, event_type, payload, failed_at, retry_at, retry_count, last_error \
+             FROM failed_events \
+             WHERE retry_at <= now() AND retry_count < $1 \
+             ORDER BY retry_at \
+             LIMIT 100",
+        )
+        .bind(DLQ_MAX_RETRIES)
+        .fetch_all(&self.pool)
+        .await
+    }
+
+    /// Advance a row after a republish attempt using exponential backoff.
+    /// next_retry = now + initial * 2^retry_count
+    pub async fn advance(&self, id: uuid::Uuid, error: Option<&str>) -> Result<(), sqlx::Error> {
+        let current: i32 =
+            sqlx::query_scalar("SELECT retry_count FROM failed_events WHERE id = $1")
+                .bind(id)
+                .fetch_one(&self.pool)
+                .await?;
+
+        let new_count = current + 1;
+        let backoff_secs = DLQ_INITIAL_BACKOFF_SECS * (1_i64 << new_count.min(10));
+        let retry_at = Utc::now() + chrono::Duration::seconds(backoff_secs);
+        let last_error = error.unwrap_or("republish succeeded");
+
+        sqlx::query(
+            "UPDATE failed_events \
+             SET retry_count = $1, retry_at = $2, last_error = $3 \
+             WHERE id = $4",
+        )
+        .bind(new_count)
+        .bind(retry_at)
+        .bind(last_error)
+        .bind(id)
+        .execute(&self.pool)
+        .await?;
+        Ok(())
+    }
+
+    /// Park a permanently failed event (retry_count >= DLQ_MAX_RETRIES).
+    pub async fn park_permanently(&self, id: uuid::Uuid) -> Result<(), sqlx::Error> {
+        let far_future = Utc::now() + chrono::Duration::days(365);
+        sqlx::query("UPDATE failed_events SET retry_at = $1 WHERE id = $2")
+            .bind(far_future)
+            .bind(id)
+            .execute(&self.pool)
+            .await?;
+        Ok(())
+    }
+}

crates/adapters/postgres/src/feed.rs

@@ -0,0 +1,399 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+
+use domain::{
+    errors::DomainError,
+    models::{
+        feed::{FeedEntry, Paginated},
+        thought::{Thought, Visibility},
+        user::User,
+    },
+    ports::{FeedQuery, FeedRepository, FeedScope},
+    value_objects::{Content, Email, PasswordHash, ThoughtId, UserId, Username},
+};
+use sqlx::PgPool;
+
+pub struct PgFeedRepository {
+    pool: PgPool,
+}
+impl PgFeedRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[derive(sqlx::FromRow)]
+struct FeedRow {
+    thought_id: uuid::Uuid,
+    t_user_id: uuid::Uuid,
+    content: String,
+    in_reply_to_id: Option<uuid::Uuid>,
+    visibility: String,
+    content_warning: Option<String>,
+    sensitive: bool,
+    t_local: bool,
+    thought_created_at: DateTime<Utc>,
+    updated_at: Option<DateTime<Utc>>,
+    author_id: uuid::Uuid,
+    username: String,
+    email: String,
+    password_hash: String,
+    display_name: Option<String>,
+    bio: Option<String>,
+    avatar_url: Option<String>,
+    header_url: Option<String>,
+    custom_css: Option<String>,
+    author_local: bool,
+    author_created_at: DateTime<Utc>,
+    author_updated_at: DateTime<Utc>,
+    like_count: i64,
+    boost_count: i64,
+    reply_count: i64,
+    liked_by_viewer: bool,
+    boosted_by_viewer: bool,
+}
+
+fn federation_following_clause(follower: Option<uuid::Uuid>) -> String {
+    match follower {
+        Some(fid) => format!(
+            " OR t.user_id IN (
+                SELECT u2.id FROM users u2
+                JOIN federation_following ff ON u2.ap_id = ff.remote_actor_url
+                WHERE ff.local_user_id = '{fid}'
+            )"
+        ),
+        None => String::new(),
+    }
+}
+
+fn feed_select(viewer: Option<uuid::Uuid>) -> String {
+    let viewer_checks = match viewer {
+        Some(uid) => format!(
+            "EXISTS(SELECT 1 FROM likes WHERE user_id='{uid}' AND thought_id=t.id) AS liked_by_viewer,
+             EXISTS(SELECT 1 FROM boosts WHERE user_id='{uid}' AND thought_id=t.id) AS boosted_by_viewer"
+        ),
+        None => "false AS liked_by_viewer, false AS boosted_by_viewer".to_string(),
+    };
+    format!(
+        "
+    SELECT
+        t.id AS thought_id, t.user_id AS t_user_id, t.content,
+        t.in_reply_to_id,
+        t.visibility, t.content_warning, t.sensitive, t.local AS t_local,
+        t.created_at AS thought_created_at, t.updated_at,
+        u.id AS author_id,
+        CASE WHEN NOT u.local AND ra.handle IS NOT NULL AND ra.handle != ''
+             THEN '@' || ra.handle ||
+                  CASE WHEN ra.handle NOT LIKE '%@%'
+                       THEN '@' || SPLIT_PART(ra.url, '/', 3)
+                       ELSE '' END
+             ELSE u.username END AS username,
+        u.email, u.password_hash,
+        COALESCE(ra.display_name, u.display_name) AS display_name,
+        u.bio,
+        COALESCE(ra.avatar_url, u.avatar_url) AS avatar_url,
+        u.header_url, u.custom_css,
+        u.local AS author_local,
+        u.created_at AS author_created_at, u.updated_at AS author_updated_at,
+        (SELECT COUNT(*) FROM likes l WHERE l.thought_id=t.id) AS like_count,
+        (SELECT COUNT(*) FROM boosts b WHERE b.thought_id=t.id) AS boost_count,
+        (SELECT COUNT(*) FROM thoughts r WHERE r.in_reply_to_id=t.id) AS reply_count,
+        {viewer_checks}
+    FROM thoughts t
+    JOIN users u ON u.id=t.user_id
+    LEFT JOIN remote_actors ra ON u.ap_id = ra.url"
+    )
+}
+
+fn row_to_entry(r: FeedRow, viewer: Option<uuid::Uuid>) -> Result<FeedEntry, DomainError> {
+    let thought = Thought {
+        id: ThoughtId::from_uuid(r.thought_id),
+        user_id: UserId::from_uuid(r.t_user_id),
+        content: Content::new_remote(r.content),
+        in_reply_to_id: r.in_reply_to_id.map(ThoughtId::from_uuid),
+        visibility: Visibility::from_db_str(&r.visibility)?,
+        content_warning: r.content_warning,
+        sensitive: r.sensitive,
+        local: r.t_local,
+        created_at: r.thought_created_at,
+        updated_at: r.updated_at,
+    };
+    let author = User {
+        id: UserId::from_uuid(r.author_id),
+        username: Username::from_trusted(r.username),
+        email: Email::from_trusted(r.email),
+        password_hash: PasswordHash(r.password_hash),
+        display_name: r.display_name,
+        bio: r.bio,
+        avatar_url: r.avatar_url,
+        header_url: r.header_url,
+        custom_css: r.custom_css,
+        local: r.author_local,
+        created_at: r.author_created_at,
+        updated_at: r.author_updated_at,
+    };
+    Ok(FeedEntry {
+        thought,
+        author,
+        stats: domain::models::feed::EngagementStats {
+            like_count: r.like_count,
+            boost_count: r.boost_count,
+            reply_count: r.reply_count,
+        },
+        viewer: viewer.map(|_| domain::models::feed::ViewerContext {
+            liked: r.liked_by_viewer,
+            boosted: r.boosted_by_viewer,
+        }),
+    })
+}
+
+#[async_trait]
+impl FeedRepository for PgFeedRepository {
+    async fn query(&self, q: &FeedQuery) -> Result<Paginated<FeedEntry>, DomainError> {
+        let viewer = q.viewer_id.as_ref().map(|v| v.as_uuid());
+        let page = &q.page;
+
+        match &q.scope {
+            FeedScope::Home { following_ids } => {
+                let ids: Vec<uuid::Uuid> = following_ids.iter().map(|id| id.as_uuid()).collect();
+                let fed_clause = federation_following_clause(viewer);
+                let count_sql = format!(
+                    "SELECT COUNT(*) FROM thoughts t WHERE (t.user_id=ANY($1){}) AND t.visibility != 'direct'",
+                    fed_clause
+                );
+                let total: i64 = sqlx::query_scalar(&count_sql)
+                    .bind(&ids)
+                    .fetch_one(&self.pool)
+                    .await
+                    .into_domain()?;
+
+                let sel = feed_select(viewer);
+                let sql = format!("{sel} WHERE (t.user_id=ANY($1){}) AND t.visibility != 'direct' ORDER BY t.created_at DESC LIMIT $2 OFFSET $3", fed_clause);
+                let rows = sqlx::query_as::<_, FeedRow>(&sql)
+                    .bind(&ids)
+                    .bind(page.limit())
+                    .bind(page.offset())
+                    .fetch_all(&self.pool)
+                    .await
+                    .into_domain()?;
+
+                Ok(Paginated {
+                    items: rows
+                        .into_iter()
+                        .map(|r| row_to_entry(r, viewer))
+                        .collect::<Result<Vec<_>, _>>()?,
+                    total,
+                    page: page.page,
+                    per_page: page.per_page,
+                })
+            }
+
+            FeedScope::Public => {
+                let total: i64 = sqlx::query_scalar(
+                    "SELECT COUNT(*) FROM thoughts t WHERE t.local=true AND t.visibility='public'",
+                )
+                .fetch_one(&self.pool)
+                .await
+                .into_domain()?;
+
+                let sel = feed_select(viewer);
+                let sql = format!("{sel} WHERE t.local=true AND t.visibility='public' ORDER BY t.created_at DESC LIMIT $1 OFFSET $2");
+                let rows = sqlx::query_as::<_, FeedRow>(&sql)
+                    .bind(page.limit())
+                    .bind(page.offset())
+                    .fetch_all(&self.pool)
+                    .await
+                    .into_domain()?;
+
+                Ok(Paginated {
+                    items: rows
+                        .into_iter()
+                        .map(|r| row_to_entry(r, viewer))
+                        .collect::<Result<Vec<_>, _>>()?,
+                    total,
+                    page: page.page,
+                    per_page: page.per_page,
+                })
+            }
+
+            FeedScope::Search { query } => {
+                let total: i64 = sqlx::query_scalar(
+                    "SELECT COUNT(*) FROM thoughts t WHERE t.content % $1 AND t.visibility='public'",
+                )
+                .bind(query)
+                .fetch_one(&self.pool)
+                .await
+                .into_domain()?;
+
+                let sel = feed_select(viewer);
+                let sql = format!("{sel} WHERE t.content % $1 AND t.visibility='public' ORDER BY similarity(t.content, $1) DESC LIMIT $2 OFFSET $3");
+                let rows = sqlx::query_as::<_, FeedRow>(&sql)
+                    .bind(query)
+                    .bind(page.limit())
+                    .bind(page.offset())
+                    .fetch_all(&self.pool)
+                    .await
+                    .into_domain()?;
+
+                Ok(Paginated {
+                    items: rows
+                        .into_iter()
+                        .map(|r| row_to_entry(r, viewer))
+                        .collect::<Result<Vec<_>, _>>()?,
+                    total,
+                    page: page.page,
+                    per_page: page.per_page,
+                })
+            }
+
+            FeedScope::Tag { tag_name } => {
+                let total: i64 = sqlx::query_scalar(
+                    "SELECT COUNT(*) FROM thoughts t
+                     JOIN thought_tags tt ON tt.thought_id = t.id
+                     JOIN tags tg ON tg.id = tt.tag_id
+                     WHERE tg.name = $1 AND t.visibility = 'public'",
+                )
+                .bind(tag_name)
+                .fetch_one(&self.pool)
+                .await
+                .into_domain()?;
+
+                let sel = feed_select(viewer);
+                let sql = format!(
+                    "{sel}
+                     JOIN thought_tags tt ON tt.thought_id = t.id
+                     JOIN tags tg ON tg.id = tt.tag_id
+                     WHERE tg.name = $1 AND t.visibility = 'public'
+                     ORDER BY t.created_at DESC LIMIT $2 OFFSET $3"
+                );
+                let rows = sqlx::query_as::<_, FeedRow>(&sql)
+                    .bind(tag_name)
+                    .bind(page.limit())
+                    .bind(page.offset())
+                    .fetch_all(&self.pool)
+                    .await
+                    .into_domain()?;
+
+                Ok(Paginated {
+                    items: rows
+                        .into_iter()
+                        .map(|r| row_to_entry(r, viewer))
+                        .collect::<Result<Vec<_>, _>>()?,
+                    total,
+                    page: page.page,
+                    per_page: page.per_page,
+                })
+            }
+
+            FeedScope::User { user_id } => {
+                let uid = user_id.as_uuid();
+                // Use nil UUID for unauthenticated viewers — won't match owner or follower checks.
+                let viewer_uuid = viewer.unwrap_or(uuid::Uuid::nil());
+
+                let total: i64 = sqlx::query_scalar(
+                    "SELECT COUNT(*) FROM thoughts t WHERE t.user_id = $1 AND ($2::uuid = $1 OR (t.visibility != 'direct' AND (t.visibility IN ('public', 'unlisted') OR (t.visibility = 'followers' AND EXISTS(SELECT 1 FROM follows WHERE follower_id = $2 AND following_id = $1 AND state = 'accepted')))))",
+                )
+                .bind(uid)
+                .bind(viewer_uuid)
+                .fetch_one(&self.pool)
+                .await
+                .into_domain()?;
+
+                let sel = feed_select(viewer);
+                let sql = format!("{sel} WHERE t.user_id = $1 AND ($4::uuid = $1 OR (t.visibility != 'direct' AND (t.visibility IN ('public', 'unlisted') OR (t.visibility = 'followers' AND EXISTS(SELECT 1 FROM follows WHERE follower_id = $4 AND following_id = $1 AND state = 'accepted'))))) ORDER BY t.created_at DESC LIMIT $2 OFFSET $3");
+                let rows = sqlx::query_as::<_, FeedRow>(&sql)
+                    .bind(uid)
+                    .bind(page.limit())
+                    .bind(page.offset())
+                    .bind(viewer_uuid)
+                    .fetch_all(&self.pool)
+                    .await
+                    .into_domain()?;
+
+                Ok(Paginated {
+                    items: rows
+                        .into_iter()
+                        .map(|r| row_to_entry(r, viewer))
+                        .collect::<Result<Vec<_>, _>>()?,
+                    total,
+                    page: page.page,
+                    per_page: page.per_page,
+                })
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{thought::PgThoughtRepository, user::PgUserRepository};
+    use domain::{
+        models::{
+            feed::PageParams,
+            thought::{Thought, Visibility},
+            user::User,
+        },
+        ports::{FeedQuery, ThoughtRepository, UserWriter},
+        value_objects::*,
+    };
+
+    async fn seed(pool: &sqlx::PgPool, username: &str, content: &str) -> (User, Thought) {
+        let urepo = PgUserRepository::new(pool.clone());
+        let trepo = PgThoughtRepository::new(pool.clone());
+        let u = User::new_local(
+            UserId::new(),
+            Username::new(username).unwrap(),
+            Email::new(format!("{username}@ex.com")).unwrap(),
+            PasswordHash("h".into()),
+        );
+        urepo.save(&u).await.unwrap();
+        let t = Thought::new_local(
+            ThoughtId::new(),
+            u.id.clone(),
+            Content::new_local(content).unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        );
+        trepo.save(&t).await.unwrap();
+        (u, t)
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn public_feed_returns_local_thoughts(pool: sqlx::PgPool) {
+        let (_, _) = seed(&pool, "alice", "hello").await;
+        let repo = PgFeedRepository::new(pool);
+        let result = repo
+            .query(&FeedQuery::public(
+                PageParams { page: 1, per_page: 20 },
+                None,
+            ))
+            .await
+            .unwrap();
+        assert_eq!(result.total, 1);
+        assert_eq!(result.items[0].thought.content.as_str(), "hello");
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn search_returns_matching_thoughts(pool: sqlx::PgPool) {
+        let (_, _) = seed(&pool, "alice", "hello world").await;
+        let (_, _) = seed(&pool, "bob", "goodbye world").await;
+        let repo = PgFeedRepository::new(pool);
+        let result = repo
+            .query(&FeedQuery::search(
+                "hello world",
+                PageParams { page: 1, per_page: 20 },
+                None,
+            ))
+            .await
+            .unwrap();
+        assert!(result.total >= 1);
+        assert!(result
+            .items
+            .iter()
+            .any(|e| e.thought.content.as_str() == "hello world"));
+    }
+}

crates/adapters/postgres/src/follow.rs

@@ -0,0 +1,252 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+
+use domain::{
+    errors::DomainError,
+    models::{
+        feed::{PageParams, Paginated},
+        social::{Follow, FollowState},
+        user::User,
+    },
+    ports::FollowRepository,
+    value_objects::UserId,
+};
+use sqlx::PgPool;
+
+pub struct PgFollowRepository {
+    pool: PgPool,
+}
+impl PgFollowRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[async_trait]
+impl FollowRepository for PgFollowRepository {
+    async fn save(&self, f: &Follow) -> Result<(), DomainError> {
+        sqlx::query(
+            "INSERT INTO follows(follower_id,following_id,state,ap_id,created_at)
+             VALUES($1,$2,$3,$4,$5)
+             ON CONFLICT(follower_id,following_id) DO UPDATE SET state=EXCLUDED.state,ap_id=EXCLUDED.ap_id"
+        )
+        .bind(f.follower_id.as_uuid())
+        .bind(f.following_id.as_uuid())
+        .bind(f.state.as_str())
+        .bind(&f.ap_id)
+        .bind(f.created_at)
+        .execute(&self.pool)
+        .await
+        .into_domain()
+        .map(|_| ())
+    }
+
+    async fn delete(&self, follower_id: &UserId, following_id: &UserId) -> Result<(), DomainError> {
+        let r = sqlx::query("DELETE FROM follows WHERE follower_id=$1 AND following_id=$2")
+            .bind(follower_id.as_uuid())
+            .bind(following_id.as_uuid())
+            .execute(&self.pool)
+            .await
+            .into_domain()?;
+        if r.rows_affected() == 0 {
+            return Err(DomainError::NotFound);
+        }
+        Ok(())
+    }
+
+    async fn find(
+        &self,
+        follower_id: &UserId,
+        following_id: &UserId,
+    ) -> Result<Option<Follow>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            follower_id: uuid::Uuid,
+            following_id: uuid::Uuid,
+            state: String,
+            ap_id: Option<String>,
+            created_at: DateTime<Utc>,
+        }
+        sqlx::query_as::<_, Row>(
+            "SELECT follower_id,following_id,state,ap_id,created_at FROM follows WHERE follower_id=$1 AND following_id=$2"
+        )
+        .bind(follower_id.as_uuid())
+        .bind(following_id.as_uuid())
+        .fetch_optional(&self.pool)
+        .await
+        .into_domain()
+        .and_then(|o| {
+            o.map(|r| {
+                Ok(Follow {
+                    follower_id: UserId::from_uuid(r.follower_id),
+                    following_id: UserId::from_uuid(r.following_id),
+                    state: FollowState::from_db_str(&r.state)?,
+                    ap_id: r.ap_id,
+                    created_at: r.created_at,
+                })
+            })
+            .transpose()
+        })
+    }
+
+    async fn update_state(
+        &self,
+        follower_id: &UserId,
+        following_id: &UserId,
+        state: &FollowState,
+    ) -> Result<(), DomainError> {
+        sqlx::query("UPDATE follows SET state=$3 WHERE follower_id=$1 AND following_id=$2")
+            .bind(follower_id.as_uuid())
+            .bind(following_id.as_uuid())
+            .bind(state.as_str())
+            .execute(&self.pool)
+            .await
+            .into_domain()
+            .map(|_| ())
+    }
+
+    async fn list_followers(
+        &self,
+        user_id: &UserId,
+        page: &PageParams,
+    ) -> Result<Paginated<User>, DomainError> {
+        let total: i64 = sqlx::query_scalar(
+            "SELECT COUNT(*) FROM follows WHERE following_id=$1 AND state='accepted'",
+        )
+        .bind(user_id.as_uuid())
+        .fetch_one(&self.pool)
+        .await
+        .into_domain()?;
+
+        let rows = sqlx::query_as::<_, crate::user::UserRow>(
+            "SELECT u.id,u.username,u.email,u.password_hash,u.display_name,u.bio,u.avatar_url,u.header_url,u.custom_css,u.local,u.ap_id,u.inbox_url,u.created_at,u.updated_at
+             FROM users u JOIN follows f ON f.follower_id=u.id
+             WHERE f.following_id=$1 AND f.state='accepted'
+             ORDER BY f.created_at DESC LIMIT $2 OFFSET $3"
+        )
+        .bind(user_id.as_uuid())
+        .bind(page.limit())
+        .bind(page.offset())
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()?;
+
+        Ok(Paginated {
+            items: rows.into_iter().map(User::from).collect(),
+            total,
+            page: page.page,
+            per_page: page.per_page,
+        })
+    }
+
+    async fn list_following(
+        &self,
+        user_id: &UserId,
+        page: &PageParams,
+    ) -> Result<Paginated<User>, DomainError> {
+        let total: i64 = sqlx::query_scalar(
+            "SELECT COUNT(*) FROM follows WHERE follower_id=$1 AND state='accepted'",
+        )
+        .bind(user_id.as_uuid())
+        .fetch_one(&self.pool)
+        .await
+        .into_domain()?;
+
+        let rows = sqlx::query_as::<_, crate::user::UserRow>(
+            "SELECT u.id,u.username,u.email,u.password_hash,u.display_name,u.bio,u.avatar_url,u.header_url,u.custom_css,u.local,u.ap_id,u.inbox_url,u.created_at,u.updated_at
+             FROM users u JOIN follows f ON f.following_id=u.id
+             WHERE f.follower_id=$1 AND f.state='accepted'
+             ORDER BY f.created_at DESC LIMIT $2 OFFSET $3"
+        )
+        .bind(user_id.as_uuid())
+        .bind(page.limit())
+        .bind(page.offset())
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()?;
+
+        Ok(Paginated {
+            items: rows.into_iter().map(User::from).collect(),
+            total,
+            page: page.page,
+            per_page: page.per_page,
+        })
+    }
+
+    async fn get_accepted_following_ids(
+        &self,
+        user_id: &UserId,
+    ) -> Result<Vec<UserId>, DomainError> {
+        let ids: Vec<uuid::Uuid> = sqlx::query_scalar(
+            "SELECT following_id FROM follows WHERE follower_id=$1 AND state='accepted'",
+        )
+        .bind(user_id.as_uuid())
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()?;
+        Ok(ids.into_iter().map(UserId::from_uuid).collect())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::test_helpers::seed_user;
+    use chrono::Utc;
+    use domain::value_objects::*;
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn save_and_find_follow(pool: sqlx::PgPool) {
+        let alice = seed_user(&pool, "alice", "alice@ex.com").await;
+        let bob = seed_user(&pool, "bob", "bob@ex.com").await;
+        let repo = PgFollowRepository::new(pool);
+        let follow = Follow {
+            follower_id: alice.id.clone(),
+            following_id: bob.id.clone(),
+            state: FollowState::Accepted,
+            ap_id: None,
+            created_at: Utc::now(),
+        };
+        repo.save(&follow).await.unwrap();
+        let found = repo.find(&alice.id, &bob.id).await.unwrap().unwrap();
+        assert_eq!(found.state, FollowState::Accepted);
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn update_state(pool: sqlx::PgPool) {
+        let alice = seed_user(&pool, "alice", "alice@ex.com").await;
+        let bob = seed_user(&pool, "bob", "bob@ex.com").await;
+        let repo = PgFollowRepository::new(pool);
+        let follow = Follow {
+            follower_id: alice.id.clone(),
+            following_id: bob.id.clone(),
+            state: FollowState::Pending,
+            ap_id: None,
+            created_at: Utc::now(),
+        };
+        repo.save(&follow).await.unwrap();
+        repo.update_state(&alice.id, &bob.id, &FollowState::Accepted)
+            .await
+            .unwrap();
+        let found = repo.find(&alice.id, &bob.id).await.unwrap().unwrap();
+        assert_eq!(found.state, FollowState::Accepted);
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn get_accepted_following_ids(pool: sqlx::PgPool) {
+        let alice = seed_user(&pool, "alice", "alice@ex.com").await;
+        let bob = seed_user(&pool, "bob", "bob@ex.com").await;
+        let repo = PgFollowRepository::new(pool);
+        let follow = Follow {
+            follower_id: alice.id.clone(),
+            following_id: bob.id.clone(),
+            state: FollowState::Accepted,
+            ap_id: None,
+            created_at: Utc::now(),
+        };
+        repo.save(&follow).await.unwrap();
+        let ids = repo.get_accepted_following_ids(&alice.id).await.unwrap();
+        assert_eq!(ids, vec![bob.id]);
+    }
+}

crates/adapters/postgres/src/lib.rs

@@ -0,0 +1,20 @@
+pub mod activitypub;
+pub mod engagement;
+pub mod api_key;
+pub mod block;
+pub mod boost;
+mod db_error;
+pub mod failed_event;
+pub mod outbox;
+pub mod feed;
+pub mod follow;
+pub mod like;
+pub mod notification;
+pub mod remote_actor;
+pub mod remote_actor_connections;
+pub mod tag;
+#[cfg(test)]
+pub(crate) mod test_helpers;
+pub mod thought;
+pub mod top_friend;
+pub mod user;

crates/adapters/postgres/src/like.rs

@@ -0,0 +1,110 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+use domain::{
+    errors::DomainError,
+    models::social::Like,
+    ports::LikeRepository,
+    value_objects::{LikeId, ThoughtId, UserId},
+};
+use sqlx::PgPool;
+
+pub struct PgLikeRepository {
+    pool: PgPool,
+}
+impl PgLikeRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[async_trait]
+impl LikeRepository for PgLikeRepository {
+    async fn save(&self, l: &Like) -> Result<(), DomainError> {
+        sqlx::query(
+            "INSERT INTO likes(id,user_id,thought_id,ap_id,created_at) VALUES($1,$2,$3,$4,$5) ON CONFLICT(user_id,thought_id) DO NOTHING"
+        )
+        .bind(l.id.as_uuid()).bind(l.user_id.as_uuid()).bind(l.thought_id.as_uuid()).bind(&l.ap_id).bind(l.created_at)
+        .execute(&self.pool).await.into_domain().map(|_| ())
+    }
+
+    async fn delete(&self, user_id: &UserId, thought_id: &ThoughtId) -> Result<(), DomainError> {
+        let r = sqlx::query("DELETE FROM likes WHERE user_id=$1 AND thought_id=$2")
+            .bind(user_id.as_uuid())
+            .bind(thought_id.as_uuid())
+            .execute(&self.pool)
+            .await
+            .into_domain()?;
+        if r.rows_affected() == 0 {
+            return Err(DomainError::NotFound);
+        }
+        Ok(())
+    }
+
+    async fn find(
+        &self,
+        user_id: &UserId,
+        thought_id: &ThoughtId,
+    ) -> Result<Option<Like>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            id: uuid::Uuid,
+            user_id: uuid::Uuid,
+            thought_id: uuid::Uuid,
+            ap_id: Option<String>,
+            created_at: DateTime<Utc>,
+        }
+        sqlx::query_as::<_, Row>("SELECT id,user_id,thought_id,ap_id,created_at FROM likes WHERE user_id=$1 AND thought_id=$2")
+            .bind(user_id.as_uuid()).bind(thought_id.as_uuid())
+            .fetch_optional(&self.pool).await
+            .into_domain()
+            .map(|o| o.map(|r| Like { id: LikeId::from_uuid(r.id), user_id: UserId::from_uuid(r.user_id), thought_id: ThoughtId::from_uuid(r.thought_id), ap_id: r.ap_id, created_at: r.created_at }))
+    }
+
+    async fn count_for_thought(&self, thought_id: &ThoughtId) -> Result<i64, DomainError> {
+        sqlx::query_scalar("SELECT COUNT(*) FROM likes WHERE thought_id=$1")
+            .bind(thought_id.as_uuid())
+            .fetch_one(&self.pool)
+            .await
+            .into_domain()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::test_helpers::seed_user_and_thought;
+    use chrono::Utc;
+    use domain::value_objects::*;
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn like_and_count(pool: sqlx::PgPool) {
+        let (user, thought) = seed_user_and_thought(&pool).await;
+        let repo = PgLikeRepository::new(pool);
+        let like = Like {
+            id: LikeId::new(),
+            user_id: user.id.clone(),
+            thought_id: thought.id.clone(),
+            ap_id: None,
+            created_at: Utc::now(),
+        };
+        repo.save(&like).await.unwrap();
+        assert_eq!(repo.count_for_thought(&thought.id).await.unwrap(), 1);
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn unlike(pool: sqlx::PgPool) {
+        let (user, thought) = seed_user_and_thought(&pool).await;
+        let repo = PgLikeRepository::new(pool);
+        let like = Like {
+            id: LikeId::new(),
+            user_id: user.id.clone(),
+            thought_id: thought.id.clone(),
+            ap_id: None,
+            created_at: Utc::now(),
+        };
+        repo.save(&like).await.unwrap();
+        repo.delete(&user.id, &thought.id).await.unwrap();
+        assert_eq!(repo.count_for_thought(&thought.id).await.unwrap(), 0);
+    }
+}

crates/adapters/postgres/src/notification.rs

@@ -0,0 +1,230 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+
+use domain::{
+    errors::DomainError,
+    models::{
+        feed::{PageParams, Paginated},
+        notification::{Notification, NotificationKind},
+    },
+    ports::NotificationRepository,
+    value_objects::{NotificationId, ThoughtId, UserId},
+};
+use sqlx::PgPool;
+
+pub struct PgNotificationRepository {
+    pool: PgPool,
+}
+impl PgNotificationRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[derive(sqlx::FromRow)]
+struct NotificationRow {
+    id: uuid::Uuid,
+    user_id: uuid::Uuid,
+    notification_type: String,
+    from_user_id: Option<uuid::Uuid>,
+    thought_id: Option<uuid::Uuid>,
+    read: bool,
+    created_at: DateTime<Utc>,
+}
+
+fn row_to_notification(r: NotificationRow) -> Result<Notification, DomainError> {
+    let from_user_id = r
+        .from_user_id
+        .map(UserId::from_uuid)
+        .ok_or_else(|| DomainError::Internal("notification missing from_user_id".into()))?;
+
+    let kind = match r.notification_type.as_str() {
+        "follow" => NotificationKind::Follow { from_user_id },
+        other => {
+            let thought_id = r.thought_id.map(ThoughtId::from_uuid).ok_or_else(|| {
+                DomainError::Internal(format!("notification type '{other}' missing thought_id"))
+            })?;
+            match other {
+                "like" => NotificationKind::Like {
+                    thought_id,
+                    from_user_id,
+                },
+                "boost" => NotificationKind::Boost {
+                    thought_id,
+                    from_user_id,
+                },
+                "reply" => NotificationKind::Reply {
+                    thought_id,
+                    from_user_id,
+                },
+                "mention" => NotificationKind::Mention {
+                    thought_id,
+                    from_user_id,
+                },
+                _ => {
+                    return Err(DomainError::Internal(format!(
+                        "unknown notification type: {other}"
+                    )))
+                }
+            }
+        }
+    };
+
+    Ok(Notification {
+        id: NotificationId::from_uuid(r.id),
+        user_id: UserId::from_uuid(r.user_id),
+        kind,
+        read: r.read,
+        created_at: r.created_at,
+    })
+}
+
+#[async_trait]
+impl NotificationRepository for PgNotificationRepository {
+    async fn save(&self, n: &Notification) -> Result<(), DomainError> {
+        sqlx::query(
+            "INSERT INTO notifications(id,user_id,notification_type,from_user_id,thought_id,read,created_at)
+             VALUES($1,$2,$3,$4,$5,$6,$7)
+             ON CONFLICT(id) DO NOTHING"
+        )
+        .bind(n.id.as_uuid())
+        .bind(n.user_id.as_uuid())
+        .bind(n.kind.kind_str())
+        .bind(n.kind.from_user_id().as_uuid())
+        .bind(n.kind.thought_id().map(|t| t.as_uuid()))
+        .bind(n.read)
+        .bind(n.created_at)
+        .execute(&self.pool)
+        .await
+        .into_domain()
+        .map(|_| ())
+    }
+
+    async fn list_for_user(
+        &self,
+        user_id: &UserId,
+        page: &PageParams,
+    ) -> Result<Paginated<Notification>, DomainError> {
+        let total: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM notifications WHERE user_id=$1")
+            .bind(user_id.as_uuid())
+            .fetch_one(&self.pool)
+            .await
+            .into_domain()?;
+        let rows = sqlx::query_as::<_, NotificationRow>(
+            "SELECT id,user_id,notification_type,from_user_id,thought_id,read,created_at FROM notifications WHERE user_id=$1 ORDER BY created_at DESC LIMIT $2 OFFSET $3"
+        ).bind(user_id.as_uuid()).bind(page.limit()).bind(page.offset())
+        .fetch_all(&self.pool).await.into_domain()?;
+        let items = rows
+            .into_iter()
+            .map(row_to_notification)
+            .collect::<Result<Vec<_>, _>>()?;
+        Ok(Paginated {
+            items,
+            total,
+            page: page.page,
+            per_page: page.per_page,
+        })
+    }
+
+    async fn count_unread(&self, user_id: &UserId) -> Result<u64, DomainError> {
+        let count: i64 = sqlx::query_scalar(
+            "SELECT COUNT(*) FROM notifications WHERE user_id=$1 AND read=false",
+        )
+        .bind(user_id.as_uuid())
+        .fetch_one(&self.pool)
+        .await
+        .into_domain()?;
+        Ok(count as u64)
+    }
+
+    async fn mark_read(&self, id: &NotificationId, user_id: &UserId) -> Result<(), DomainError> {
+        sqlx::query("UPDATE notifications SET read=true WHERE id=$1 AND user_id=$2")
+            .bind(id.as_uuid())
+            .bind(user_id.as_uuid())
+            .execute(&self.pool)
+            .await
+            .into_domain()
+            .map(|_| ())
+    }
+
+    async fn mark_all_read(&self, user_id: &UserId) -> Result<(), DomainError> {
+        sqlx::query("UPDATE notifications SET read=true WHERE user_id=$1")
+            .bind(user_id.as_uuid())
+            .execute(&self.pool)
+            .await
+            .into_domain()
+            .map(|_| ())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::test_helpers;
+    use chrono::Utc;
+    use domain::{
+        models::{notification::NotificationKind, user::User},
+        value_objects::*,
+    };
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn save_and_list(pool: sqlx::PgPool) {
+        let user = test_helpers::seed_user(&pool, "alice", "alice@ex.com").await;
+        let from_user = test_helpers::seed_user(&pool, "bob", "bob@ex.com").await;
+        let repo = PgNotificationRepository::new(pool);
+        use domain::models::feed::PageParams;
+        let n = Notification {
+            id: NotificationId::new(),
+            user_id: user.id.clone(),
+            kind: NotificationKind::Follow {
+                from_user_id: from_user.id.clone(),
+            },
+            read: false,
+            created_at: Utc::now(),
+        };
+        repo.save(&n).await.unwrap();
+        let page = repo
+            .list_for_user(
+                &user.id,
+                &PageParams {
+                    page: 1,
+                    per_page: 20,
+                },
+            )
+            .await
+            .unwrap();
+        assert_eq!(page.total, 1);
+        assert!(!page.items[0].read);
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn mark_all_read(pool: sqlx::PgPool) {
+        let user = test_helpers::seed_user(&pool, "alice", "alice@ex.com").await;
+        let from_user = test_helpers::seed_user(&pool, "bob", "bob@ex.com").await;
+        let repo = PgNotificationRepository::new(pool);
+        use domain::models::feed::PageParams;
+        let n = Notification {
+            id: NotificationId::new(),
+            user_id: user.id.clone(),
+            kind: NotificationKind::Follow {
+                from_user_id: from_user.id.clone(),
+            },
+            read: false,
+            created_at: Utc::now(),
+        };
+        repo.save(&n).await.unwrap();
+        repo.mark_all_read(&user.id).await.unwrap();
+        let page = repo
+            .list_for_user(
+                &user.id,
+                &PageParams {
+                    page: 1,
+                    per_page: 20,
+                },
+            )
+            .await
+            .unwrap();
+        assert!(page.items[0].read);
+    }
+}

crates/adapters/postgres/src/outbox.rs

@@ -0,0 +1,61 @@
+use async_trait::async_trait;
+use domain::{errors::DomainError, events::DomainEvent, ports::OutboxWriter};
+use event_payload::EventPayload;
+use sqlx::PgPool;
+use uuid::Uuid;
+
+pub struct PgOutboxWriter {
+    pool: PgPool,
+}
+
+impl PgOutboxWriter {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+/// Primary aggregate UUID for an event — used to populate `aggregate_id`.
+fn aggregate_id(event: &DomainEvent) -> Uuid {
+    match event {
+        DomainEvent::ThoughtCreated { thought_id, .. } => thought_id.as_uuid(),
+        DomainEvent::ThoughtDeleted { thought_id, .. } => thought_id.as_uuid(),
+        DomainEvent::ThoughtUpdated { thought_id, .. } => thought_id.as_uuid(),
+        DomainEvent::LikeAdded { thought_id, .. } => thought_id.as_uuid(),
+        DomainEvent::LikeRemoved { thought_id, .. } => thought_id.as_uuid(),
+        DomainEvent::BoostAdded { thought_id, .. } => thought_id.as_uuid(),
+        DomainEvent::BoostRemoved { thought_id, .. } => thought_id.as_uuid(),
+        DomainEvent::FollowRequested { follower_id, .. } => follower_id.as_uuid(),
+        DomainEvent::FollowAccepted { follower_id, .. } => follower_id.as_uuid(),
+        DomainEvent::FollowRejected { follower_id, .. } => follower_id.as_uuid(),
+        DomainEvent::Unfollowed { follower_id, .. } => follower_id.as_uuid(),
+        DomainEvent::UserBlocked { blocker_id, .. } => blocker_id.as_uuid(),
+        DomainEvent::UserUnblocked { blocker_id, .. } => blocker_id.as_uuid(),
+        DomainEvent::UserRegistered { user_id } => user_id.as_uuid(),
+        DomainEvent::ProfileUpdated { user_id } => user_id.as_uuid(),
+        DomainEvent::MentionReceived { thought_id, .. } => thought_id.as_uuid(),
+    }
+}
+
+#[async_trait]
+impl OutboxWriter for PgOutboxWriter {
+    async fn append(&self, event: &DomainEvent) -> Result<(), DomainError> {
+        let payload = EventPayload::from(event);
+        let event_type = payload.subject();
+        let payload_json =
+            serde_json::to_value(&payload).map_err(|e| DomainError::Internal(e.to_string()))?;
+        let agg_id = aggregate_id(event);
+
+        sqlx::query(
+            "INSERT INTO outbox_events (aggregate_id, event_type, payload) \
+             VALUES ($1, $2, $3)",
+        )
+        .bind(agg_id)
+        .bind(event_type)
+        .bind(payload_json)
+        .execute(&self.pool)
+        .await
+        .map_err(|e| DomainError::Internal(e.to_string()))?;
+
+        Ok(())
+    }
+}

crates/adapters/postgres/src/remote_actor.rs

@@ -0,0 +1,59 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+use domain::{
+    errors::DomainError, models::remote_actor::RemoteActor, ports::RemoteActorRepository,
+};
+use sqlx::PgPool;
+
+pub struct PgRemoteActorRepository {
+    pool: PgPool,
+}
+impl PgRemoteActorRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[async_trait]
+impl RemoteActorRepository for PgRemoteActorRepository {
+    async fn upsert(&self, a: &RemoteActor) -> Result<(), DomainError> {
+        sqlx::query(
+            "INSERT INTO remote_actors(url,handle,display_name,avatar_url,last_fetched_at)
+             VALUES($1,$2,$3,$4,$5)
+             ON CONFLICT(url) DO UPDATE SET handle=EXCLUDED.handle,display_name=EXCLUDED.display_name,
+             avatar_url=EXCLUDED.avatar_url,last_fetched_at=EXCLUDED.last_fetched_at"
+        )
+        .bind(&a.url).bind(&a.handle).bind(&a.display_name).bind(&a.avatar_url).bind(a.last_fetched_at)
+        .execute(&self.pool).await.into_domain().map(|_| ())
+    }
+
+    async fn find_by_url(&self, url: &str) -> Result<Option<RemoteActor>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            url: String,
+            handle: String,
+            display_name: Option<String>,
+            avatar_url: Option<String>,
+            last_fetched_at: DateTime<Utc>,
+        }
+        sqlx::query_as::<_, Row>(
+            "SELECT url,handle,display_name,avatar_url,last_fetched_at FROM remote_actors WHERE url=$1"
+        ).bind(url).fetch_optional(&self.pool).await
+        .into_domain()
+        .map(|o| o.map(|r| RemoteActor {
+            url: r.url,
+            handle: r.handle,
+            display_name: r.display_name,
+            avatar_url: r.avatar_url,
+            last_fetched_at: r.last_fetched_at,
+            bio: None,
+            banner_url: None,
+            also_known_as: None,
+            outbox_url: None,
+            followers_url: None,
+            following_url: None,
+            attachment: vec![],
+        }))
+    }
+}

crates/adapters/postgres/src/remote_actor_connections.rs

@@ -0,0 +1,111 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use domain::{
+    errors::DomainError, models::actor_connection_summary::ActorConnectionSummary,
+    ports::RemoteActorConnectionRepository,
+};
+use sqlx::PgPool;
+
+pub struct PgRemoteActorConnectionRepository {
+    pool: PgPool,
+}
+
+impl PgRemoteActorConnectionRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[async_trait]
+impl RemoteActorConnectionRepository for PgRemoteActorConnectionRepository {
+    async fn upsert_connections(
+        &self,
+        actor_url: &str,
+        connection_type: &str,
+        page: u32,
+        actors: &[ActorConnectionSummary],
+    ) -> Result<(), DomainError> {
+        for actor in actors {
+            sqlx::query(
+                "INSERT INTO remote_actor_connections
+                    (actor_url, connection_type, page, connected_actor_url,
+                     connected_handle, connected_display_name, connected_avatar_url, fetched_at)
+                 VALUES ($1, $2, $3, $4, $5, $6, $7, NOW())
+                 ON CONFLICT(actor_url, connection_type, page, connected_actor_url)
+                 DO UPDATE SET
+                     connected_handle       = EXCLUDED.connected_handle,
+                     connected_display_name = EXCLUDED.connected_display_name,
+                     connected_avatar_url   = EXCLUDED.connected_avatar_url,
+                     fetched_at             = NOW()",
+            )
+            .bind(actor_url)
+            .bind(connection_type)
+            .bind(page as i32)
+            .bind(&actor.url)
+            .bind(&actor.handle)
+            .bind(&actor.display_name)
+            .bind(&actor.avatar_url)
+            .execute(&self.pool)
+            .await
+            .into_domain()?;
+        }
+        Ok(())
+    }
+
+    async fn list_connections(
+        &self,
+        actor_url: &str,
+        connection_type: &str,
+        page: u32,
+    ) -> Result<Vec<ActorConnectionSummary>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            connected_actor_url: String,
+            connected_handle: String,
+            connected_display_name: Option<String>,
+            connected_avatar_url: Option<String>,
+        }
+        let rows = sqlx::query_as::<_, Row>(
+            "SELECT connected_actor_url, connected_handle, connected_display_name, connected_avatar_url
+             FROM remote_actor_connections
+             WHERE actor_url = $1 AND connection_type = $2 AND page = $3
+             ORDER BY connected_handle",
+        )
+        .bind(actor_url)
+        .bind(connection_type)
+        .bind(page as i32)
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()?;
+
+        Ok(rows
+            .into_iter()
+            .map(|r| ActorConnectionSummary {
+                url: r.connected_actor_url,
+                handle: r.connected_handle,
+                display_name: r.connected_display_name,
+                avatar_url: r.connected_avatar_url,
+            })
+            .collect())
+    }
+
+    async fn connection_page_age(
+        &self,
+        actor_url: &str,
+        connection_type: &str,
+        page: u32,
+    ) -> Result<Option<chrono::DateTime<chrono::Utc>>, DomainError> {
+        let row: Option<(Option<chrono::DateTime<chrono::Utc>>,)> = sqlx::query_as(
+            "SELECT MAX(fetched_at) FROM remote_actor_connections
+             WHERE actor_url = $1 AND connection_type = $2 AND page = $3",
+        )
+        .bind(actor_url)
+        .bind(connection_type)
+        .bind(page as i32)
+        .fetch_optional(&self.pool)
+        .await
+        .into_domain()?;
+
+        Ok(row.and_then(|(ts,)| ts))
+    }
+}

crates/adapters/postgres/src/tag.rs

@@ -0,0 +1,184 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use domain::{
+    errors::DomainError,
+    models::{
+        feed::{PageParams, Paginated},
+        tag::Tag,
+        thought::Thought,
+    },
+    ports::TagRepository,
+    value_objects::ThoughtId,
+};
+use sqlx::PgPool;
+
+pub struct PgTagRepository {
+    pool: PgPool,
+}
+impl PgTagRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[async_trait]
+impl TagRepository for PgTagRepository {
+    async fn find_or_create(&self, name: &str) -> Result<Tag, DomainError> {
+        let name = name.to_lowercase();
+        sqlx::query("INSERT INTO tags(name) VALUES($1) ON CONFLICT(name) DO NOTHING")
+            .bind(&name)
+            .execute(&self.pool)
+            .await
+            .into_domain()?;
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            id: i32,
+            name: String,
+        }
+        let row = sqlx::query_as::<_, Row>("SELECT id,name FROM tags WHERE name=$1")
+            .bind(&name)
+            .fetch_one(&self.pool)
+            .await
+            .into_domain()?;
+        Ok(Tag {
+            id: row.id,
+            name: row.name,
+        })
+    }
+
+    async fn attach_to_thought(
+        &self,
+        thought_id: &ThoughtId,
+        tag_id: i32,
+    ) -> Result<(), DomainError> {
+        sqlx::query(
+            "INSERT INTO thought_tags(thought_id,tag_id) VALUES($1,$2) ON CONFLICT DO NOTHING",
+        )
+        .bind(thought_id.as_uuid())
+        .bind(tag_id)
+        .execute(&self.pool)
+        .await
+        .into_domain()
+        .map(|_| ())
+    }
+
+    async fn detach_from_thought(&self, thought_id: &ThoughtId) -> Result<(), DomainError> {
+        sqlx::query("DELETE FROM thought_tags WHERE thought_id=$1")
+            .bind(thought_id.as_uuid())
+            .execute(&self.pool)
+            .await
+            .into_domain()
+            .map(|_| ())
+    }
+
+    async fn list_for_thought(&self, thought_id: &ThoughtId) -> Result<Vec<Tag>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            id: i32,
+            name: String,
+        }
+        sqlx::query_as::<_, Row>(
+            "SELECT t.id,t.name FROM tags t JOIN thought_tags tt ON tt.tag_id=t.id WHERE tt.thought_id=$1"
+        ).bind(thought_id.as_uuid()).fetch_all(&self.pool).await
+        .into_domain()
+        .map(|rows| rows.into_iter().map(|r| Tag { id: r.id, name: r.name }).collect())
+    }
+
+    async fn list_thoughts_by_tag(
+        &self,
+        tag_name: &str,
+        page: &PageParams,
+    ) -> Result<Paginated<Thought>, DomainError> {
+        let total: i64 = sqlx::query_scalar(
+            "SELECT COUNT(*) FROM thought_tags tt JOIN tags t ON t.id=tt.tag_id WHERE t.name=$1",
+        )
+        .bind(tag_name)
+        .fetch_one(&self.pool)
+        .await
+        .into_domain()?;
+
+        let rows = sqlx::query_as::<_, crate::thought::ThoughtRow>(
+            "SELECT th.id,th.user_id,th.content,th.in_reply_to_id,th.in_reply_to_url,th.ap_id,th.visibility,th.content_warning,th.sensitive,th.local,th.created_at,th.updated_at
+             FROM thoughts th JOIN thought_tags tt ON tt.thought_id=th.id JOIN tags t ON t.id=tt.tag_id
+             WHERE t.name=$1 ORDER BY th.created_at DESC LIMIT $2 OFFSET $3"
+        ).bind(tag_name).bind(page.limit()).bind(page.offset())
+        .fetch_all(&self.pool).await.into_domain()?;
+
+        Ok(Paginated {
+            items: rows
+                .into_iter()
+                .map(Thought::try_from)
+                .collect::<Result<Vec<_>, _>>()?,
+            total,
+            page: page.page,
+            per_page: page.per_page,
+        })
+    }
+
+    async fn popular_tags(&self, limit: usize) -> Result<Vec<(String, i64)>, DomainError> {
+        sqlx::query_as::<_, (String, i64)>(
+            "SELECT t.name, COUNT(tt.thought_id) AS thought_count
+             FROM tags t
+             JOIN thought_tags tt ON t.id = tt.tag_id
+             GROUP BY t.id, t.name
+             ORDER BY thought_count DESC
+             LIMIT $1",
+        )
+        .bind(limit as i64)
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::{thought::PgThoughtRepository, user::PgUserRepository};
+    use domain::ports::{ThoughtRepository, UserWriter};
+    use domain::{
+        models::{
+            thought::{Thought, Visibility},
+            user::User,
+        },
+        value_objects::*,
+    };
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn find_or_create_tag(pool: sqlx::PgPool) {
+        let repo = PgTagRepository::new(pool);
+        let t1 = repo.find_or_create("rust").await.unwrap();
+        let t2 = repo.find_or_create("rust").await.unwrap();
+        assert_eq!(t1.id, t2.id);
+        assert_eq!(t1.name, "rust");
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn attach_and_list(pool: sqlx::PgPool) {
+        let urepo = PgUserRepository::new(pool.clone());
+        let trepo = PgThoughtRepository::new(pool.clone());
+        let u = User::new_local(
+            UserId::new(),
+            Username::new("alice").unwrap(),
+            Email::new("alice@ex.com").unwrap(),
+            PasswordHash("h".into()),
+        );
+        urepo.save(&u).await.unwrap();
+        let t = Thought::new_local(
+            ThoughtId::new(),
+            u.id.clone(),
+            Content::new_local("hi").unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        );
+        trepo.save(&t).await.unwrap();
+        let repo = PgTagRepository::new(pool);
+        let tag = repo.find_or_create("greetings").await.unwrap();
+        repo.attach_to_thought(&t.id, tag.id).await.unwrap();
+        let tags = repo.list_for_thought(&t.id).await.unwrap();
+        assert_eq!(tags.len(), 1);
+        assert_eq!(tags[0].name, "greetings");
+    }
+}

crates/adapters/postgres/src/test_helpers.rs

@@ -0,0 +1,37 @@
+use crate::{thought::PgThoughtRepository, user::PgUserRepository};
+use domain::{
+    models::{
+        thought::{Thought, Visibility},
+        user::User,
+    },
+    ports::{ThoughtRepository, UserWriter},
+    value_objects::{Content, Email, PasswordHash, ThoughtId, UserId, Username},
+};
+
+pub async fn seed_user(pool: &sqlx::PgPool, username: &str, email: &str) -> User {
+    let repo = PgUserRepository::new(pool.clone());
+    let u = User::new_local(
+        UserId::new(),
+        Username::new(username).unwrap(),
+        Email::new(email).unwrap(),
+        PasswordHash("h".into()),
+    );
+    repo.save(&u).await.unwrap();
+    u
+}
+
+pub async fn seed_user_and_thought(pool: &sqlx::PgPool) -> (User, Thought) {
+    let user = seed_user(pool, "alice", "alice@ex.com").await;
+    let trepo = PgThoughtRepository::new(pool.clone());
+    let t = Thought::new_local(
+        ThoughtId::new(),
+        user.id.clone(),
+        Content::new_local("hi").unwrap(),
+        None,
+        Visibility::Public,
+        None,
+        false,
+    );
+    trepo.save(&t).await.unwrap();
+    (user, t)
+}

crates/adapters/postgres/src/thought.rs

@@ -0,0 +1,262 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+
+use domain::{
+    errors::DomainError,
+    models::{
+        feed::{PageParams, Paginated},
+        thought::{Thought, Visibility},
+    },
+    ports::ThoughtRepository,
+    value_objects::{Content, ThoughtId, UserId},
+};
+use sqlx::PgPool;
+
+pub struct PgThoughtRepository {
+    pool: PgPool,
+}
+impl PgThoughtRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[derive(sqlx::FromRow)]
+pub(crate) struct ThoughtRow {
+    pub id: uuid::Uuid,
+    pub user_id: uuid::Uuid,
+    pub content: String,
+    pub in_reply_to_id: Option<uuid::Uuid>,
+    pub visibility: String,
+    pub content_warning: Option<String>,
+    pub sensitive: bool,
+    pub local: bool,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: Option<DateTime<Utc>>,
+}
+
+impl TryFrom<ThoughtRow> for Thought {
+    type Error = DomainError;
+    fn try_from(r: ThoughtRow) -> Result<Self, DomainError> {
+        Ok(Thought {
+            id: ThoughtId::from_uuid(r.id),
+            user_id: UserId::from_uuid(r.user_id),
+            content: Content::new_remote(r.content),
+            in_reply_to_id: r.in_reply_to_id.map(ThoughtId::from_uuid),
+            visibility: Visibility::from_db_str(&r.visibility)?,
+            content_warning: r.content_warning,
+            sensitive: r.sensitive,
+            local: r.local,
+            created_at: r.created_at,
+            updated_at: r.updated_at,
+        })
+    }
+}
+
+const THOUGHT_SELECT: &str =
+    "SELECT id,user_id,content,in_reply_to_id,visibility,content_warning,sensitive,local,created_at,updated_at FROM thoughts";
+
+#[async_trait]
+impl ThoughtRepository for PgThoughtRepository {
+    async fn save(&self, t: &Thought) -> Result<(), DomainError> {
+        sqlx::query(
+            "INSERT INTO thoughts(id,user_id,content,in_reply_to_id,visibility,content_warning,sensitive,local,created_at)
+             VALUES($1,$2,$3,$4,$5,$6,$7,$8,$9)
+             ON CONFLICT(id) DO UPDATE SET content=EXCLUDED.content,updated_at=NOW()"
+        )
+        .bind(t.id.as_uuid())
+        .bind(t.user_id.as_uuid())
+        .bind(t.content.as_str())
+        .bind(t.in_reply_to_id.as_ref().map(|x| x.as_uuid()))
+        .bind(t.visibility.as_str())
+        .bind(&t.content_warning)
+        .bind(t.sensitive)
+        .bind(t.local)
+        .bind(t.created_at)
+        .execute(&self.pool)
+        .await
+        .into_domain()
+        .map(|_| ())
+    }
+
+    async fn find_by_id(&self, id: &ThoughtId) -> Result<Option<Thought>, DomainError> {
+        sqlx::query_as::<_, ThoughtRow>(&format!("{THOUGHT_SELECT} WHERE id=$1"))
+            .bind(id.as_uuid())
+            .fetch_optional(&self.pool)
+            .await
+            .into_domain()
+            .and_then(|o| o.map(Thought::try_from).transpose())
+    }
+
+    async fn delete(&self, id: &ThoughtId, user_id: &UserId) -> Result<(), DomainError> {
+        let r = sqlx::query("DELETE FROM thoughts WHERE id=$1 AND user_id=$2")
+            .bind(id.as_uuid())
+            .bind(user_id.as_uuid())
+            .execute(&self.pool)
+            .await
+            .into_domain()?;
+        if r.rows_affected() == 0 {
+            return Err(DomainError::NotFound);
+        }
+        Ok(())
+    }
+
+    async fn update_content(&self, id: &ThoughtId, content: &Content) -> Result<(), DomainError> {
+        sqlx::query("UPDATE thoughts SET content=$2,updated_at=NOW() WHERE id=$1")
+            .bind(id.as_uuid())
+            .bind(content.as_str())
+            .execute(&self.pool)
+            .await
+            .into_domain()
+            .map(|_| ())
+    }
+
+    async fn get_thread(&self, id: &ThoughtId) -> Result<Vec<Thought>, DomainError> {
+        // Recursive CTE: fetches the root thought and all nested replies at any depth.
+        sqlx::query_as::<_, ThoughtRow>(
+            "WITH RECURSIVE thread AS (
+                SELECT id,user_id,content,in_reply_to_id,
+                       visibility,content_warning,sensitive,local,created_at,updated_at
+                FROM thoughts WHERE id = $1
+                UNION ALL
+                SELECT t.id,t.user_id,t.content,t.in_reply_to_id,
+                       t.visibility,t.content_warning,t.sensitive,t.local,t.created_at,t.updated_at
+                FROM thoughts t JOIN thread ON t.in_reply_to_id = thread.id
+            )
+            SELECT * FROM thread ORDER BY created_at ASC",
+        )
+        .bind(id.as_uuid())
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()
+        .and_then(|rows| rows.into_iter().map(Thought::try_from).collect())
+    }
+
+    async fn list_by_user(
+        &self,
+        user_id: &UserId,
+        page: &PageParams,
+    ) -> Result<Paginated<Thought>, DomainError> {
+        let uid = user_id.as_uuid();
+        let total: i64 = sqlx::query_scalar("SELECT COUNT(*) FROM thoughts WHERE user_id = $1")
+            .bind(uid)
+            .fetch_one(&self.pool)
+            .await
+            .into_domain()?;
+
+        let rows = sqlx::query_as::<_, ThoughtRow>(&format!(
+            "{THOUGHT_SELECT} WHERE user_id=$1 ORDER BY created_at DESC LIMIT $2 OFFSET $3"
+        ))
+        .bind(uid)
+        .bind(page.limit())
+        .bind(page.offset())
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()?;
+
+        Ok(Paginated {
+            items: rows
+                .into_iter()
+                .map(Thought::try_from)
+                .collect::<Result<Vec<_>, _>>()?,
+            total,
+            page: page.page,
+            per_page: page.per_page,
+        })
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::test_helpers::seed_user;
+    use domain::{
+        models::thought::{Thought, Visibility},
+        value_objects::*,
+    };
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn save_and_find_thought(pool: sqlx::PgPool) {
+        let user = seed_user(&pool, "alice", "alice@ex.com").await;
+        let repo = PgThoughtRepository::new(pool);
+        let t = Thought::new_local(
+            ThoughtId::new(),
+            user.id.clone(),
+            Content::new_local("hello world").unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        );
+        repo.save(&t).await.unwrap();
+        let found = repo.find_by_id(&t.id).await.unwrap().unwrap();
+        assert_eq!(found.content.as_str(), "hello world");
+        assert!(found.local);
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn delete_thought(pool: sqlx::PgPool) {
+        let user = seed_user(&pool, "bob", "bob@ex.com").await;
+        let repo = PgThoughtRepository::new(pool);
+        let t = Thought::new_local(
+            ThoughtId::new(),
+            user.id.clone(),
+            Content::new_local("bye").unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        );
+        repo.save(&t).await.unwrap();
+        repo.delete(&t.id, &user.id).await.unwrap();
+        assert!(repo.find_by_id(&t.id).await.unwrap().is_none());
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn delete_wrong_owner_returns_not_found(pool: sqlx::PgPool) {
+        let alice = seed_user(&pool, "alice", "alice@ex.com").await;
+        let bob = seed_user(&pool, "bob", "bob@ex.com").await;
+        let repo = PgThoughtRepository::new(pool);
+        let t = Thought::new_local(
+            ThoughtId::new(),
+            alice.id.clone(),
+            Content::new_local("secret").unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        );
+        repo.save(&t).await.unwrap();
+        let err = repo.delete(&t.id, &bob.id).await.unwrap_err();
+        assert!(matches!(err, DomainError::NotFound));
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn get_thread_returns_root_and_replies(pool: sqlx::PgPool) {
+        let user = seed_user(&pool, "charlie", "charlie@ex.com").await;
+        let repo = PgThoughtRepository::new(pool);
+        let root = Thought::new_local(
+            ThoughtId::new(),
+            user.id.clone(),
+            Content::new_local("root").unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        );
+        let reply = Thought::new_local(
+            ThoughtId::new(),
+            user.id.clone(),
+            Content::new_local("reply").unwrap(),
+            Some(root.id.clone()),
+            Visibility::Public,
+            None,
+            false,
+        );
+        repo.save(&root).await.unwrap();
+        repo.save(&reply).await.unwrap();
+        let thread = repo.get_thread(&root.id).await.unwrap();
+        assert_eq!(thread.len(), 2);
+    }
+}

crates/adapters/postgres/src/top_friend.rs

@@ -0,0 +1,155 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use domain::{
+    errors::DomainError,
+    models::{top_friend::TopFriend, user::User},
+    ports::TopFriendRepository,
+    value_objects::UserId,
+};
+use sqlx::PgPool;
+
+pub struct PgTopFriendRepository {
+    pool: PgPool,
+}
+impl PgTopFriendRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[async_trait]
+impl TopFriendRepository for PgTopFriendRepository {
+    async fn set_top_friends(
+        &self,
+        user_id: &UserId,
+        friends: Vec<(UserId, i16)>,
+    ) -> Result<(), DomainError> {
+        let mut tx = self.pool.begin().await.into_domain()?;
+        sqlx::query("DELETE FROM top_friends WHERE user_id=$1")
+            .bind(user_id.as_uuid())
+            .execute(&mut *tx)
+            .await
+            .into_domain()?;
+        for (friend_id, pos) in friends {
+            sqlx::query("INSERT INTO top_friends(user_id,friend_id,position) VALUES($1,$2,$3)")
+                .bind(user_id.as_uuid())
+                .bind(friend_id.as_uuid())
+                .bind(pos)
+                .execute(&mut *tx)
+                .await
+                .into_domain()?;
+        }
+        tx.commit().await.into_domain()
+    }
+
+    async fn list_for_user(&self, user_id: &UserId) -> Result<Vec<(TopFriend, User)>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            tf_user_id: uuid::Uuid,
+            friend_id: uuid::Uuid,
+            position: i16,
+            id: uuid::Uuid,
+            username: String,
+            email: String,
+            password_hash: String,
+            display_name: Option<String>,
+            bio: Option<String>,
+            avatar_url: Option<String>,
+            header_url: Option<String>,
+            custom_css: Option<String>,
+            local: bool,
+            created_at: chrono::DateTime<chrono::Utc>,
+            updated_at: chrono::DateTime<chrono::Utc>,
+        }
+        let rows = sqlx::query_as::<_, Row>(
+            "SELECT tf.user_id AS tf_user_id, tf.friend_id, tf.position,
+             u.id, u.username, u.email, u.password_hash, u.display_name, u.bio,
+             u.avatar_url, u.header_url, u.custom_css, u.local,
+             u.created_at, u.updated_at
+             FROM top_friends tf JOIN users u ON u.id=tf.friend_id
+             WHERE tf.user_id=$1 ORDER BY tf.position",
+        )
+        .bind(user_id.as_uuid())
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()?;
+
+        Ok(rows
+            .into_iter()
+            .map(|r| {
+                use domain::value_objects::{Email, PasswordHash, Username};
+                let tf = TopFriend {
+                    user_id: UserId::from_uuid(r.tf_user_id),
+                    friend_id: UserId::from_uuid(r.friend_id),
+                    position: r.position,
+                };
+                let u = User {
+                    id: UserId::from_uuid(r.id),
+                    username: Username::from_trusted(r.username),
+                    email: Email::from_trusted(r.email),
+                    password_hash: PasswordHash(r.password_hash),
+                    display_name: r.display_name,
+                    bio: r.bio,
+                    avatar_url: r.avatar_url,
+                    header_url: r.header_url,
+                    custom_css: r.custom_css,
+                    local: r.local,
+                    created_at: r.created_at,
+                    updated_at: r.updated_at,
+                };
+                (tf, u)
+            })
+            .collect())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use crate::user::PgUserRepository;
+    use domain::ports::UserWriter;
+    use domain::{models::user::User, value_objects::*};
+
+    async fn seed_user(pool: &sqlx::PgPool, username: &str, email: &str) -> User {
+        let repo = PgUserRepository::new(pool.clone());
+        let u = User::new_local(
+            UserId::new(),
+            Username::new(username).unwrap(),
+            Email::new(email).unwrap(),
+            PasswordHash("h".into()),
+        );
+        repo.save(&u).await.unwrap();
+        u
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn set_and_list_top_friends(pool: sqlx::PgPool) {
+        let alice = seed_user(&pool, "alice", "alice@ex.com").await;
+        let bob = seed_user(&pool, "bob", "bob@ex.com").await;
+        let repo = PgTopFriendRepository::new(pool);
+        repo.set_top_friends(&alice.id, vec![(bob.id.clone(), 1)])
+            .await
+            .unwrap();
+        let friends = repo.list_for_user(&alice.id).await.unwrap();
+        assert_eq!(friends.len(), 1);
+        assert_eq!(friends[0].0.position, 1);
+        assert_eq!(friends[0].1.username.as_str(), "bob");
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn replace_top_friends(pool: sqlx::PgPool) {
+        let alice = seed_user(&pool, "alice", "alice@ex.com").await;
+        let bob = seed_user(&pool, "bob", "bob@ex.com").await;
+        let carol = seed_user(&pool, "carol", "carol@ex.com").await;
+        let repo = PgTopFriendRepository::new(pool);
+        repo.set_top_friends(&alice.id, vec![(bob.id.clone(), 1)])
+            .await
+            .unwrap();
+        repo.set_top_friends(&alice.id, vec![(carol.id.clone(), 1)])
+            .await
+            .unwrap();
+        let friends = repo.list_for_user(&alice.id).await.unwrap();
+        assert_eq!(friends.len(), 1);
+        assert_eq!(friends[0].1.username.as_str(), "carol");
+    }
+}

crates/adapters/postgres/src/user.rs

@@ -0,0 +1,352 @@
+use crate::db_error::IntoDbResult;
+use async_trait::async_trait;
+use chrono::{DateTime, Utc};
+use domain::{
+    errors::DomainError,
+    models::feed::{PageParams, Paginated, UserSummary},
+    models::user::User,
+    ports::{UserReader, UserWriter},
+    value_objects::{Email, PasswordHash, UserId, Username},
+};
+use sqlx::PgPool;
+use std::collections::HashMap;
+
+pub struct PgUserRepository {
+    pool: PgPool,
+}
+impl PgUserRepository {
+    pub fn new(pool: PgPool) -> Self {
+        Self { pool }
+    }
+}
+
+#[derive(sqlx::FromRow)]
+pub struct UserRow {
+    pub id: uuid::Uuid,
+    pub username: String,
+    pub email: String,
+    pub password_hash: String,
+    pub display_name: Option<String>,
+    pub bio: Option<String>,
+    pub avatar_url: Option<String>,
+    pub header_url: Option<String>,
+    pub custom_css: Option<String>,
+    pub local: bool,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: DateTime<Utc>,
+}
+
+impl From<UserRow> for User {
+    fn from(r: UserRow) -> Self {
+        User {
+            id: UserId::from_uuid(r.id),
+            username: Username::from_trusted(r.username),
+            email: Email::from_trusted(r.email),
+            password_hash: PasswordHash(r.password_hash),
+            display_name: r.display_name,
+            bio: r.bio,
+            avatar_url: r.avatar_url,
+            header_url: r.header_url,
+            custom_css: r.custom_css,
+            local: r.local,
+            created_at: r.created_at,
+            updated_at: r.updated_at,
+        }
+    }
+}
+
+pub const USER_SELECT: &str =
+    "SELECT id,username,email,password_hash,display_name,bio,avatar_url,header_url,\
+     custom_css,local,created_at,updated_at FROM users";
+
+#[async_trait]
+impl UserReader for PgUserRepository {
+    async fn find_by_id(&self, id: &UserId) -> Result<Option<User>, DomainError> {
+        sqlx::query_as::<_, UserRow>(&format!("{USER_SELECT} WHERE id=$1"))
+            .bind(id.as_uuid())
+            .fetch_optional(&self.pool)
+            .await
+            .into_domain()
+            .map(|o| o.map(User::from))
+    }
+
+    async fn find_by_username(&self, username: &Username) -> Result<Option<User>, DomainError> {
+        sqlx::query_as::<_, UserRow>(&format!("{USER_SELECT} WHERE username=$1"))
+            .bind(username.as_str())
+            .fetch_optional(&self.pool)
+            .await
+            .into_domain()
+            .map(|o| o.map(User::from))
+    }
+
+    async fn find_by_email(&self, email: &Email) -> Result<Option<User>, DomainError> {
+        sqlx::query_as::<_, UserRow>(&format!("{USER_SELECT} WHERE email=$1"))
+            .bind(email.as_str())
+            .fetch_optional(&self.pool)
+            .await
+            .into_domain()
+            .map(|o| o.map(User::from))
+    }
+
+    async fn list_with_stats(&self) -> Result<Vec<UserSummary>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            id: uuid::Uuid,
+            username: String,
+            display_name: Option<String>,
+            avatar_url: Option<String>,
+            bio: Option<String>,
+            thought_count: i64,
+            follower_count: i64,
+            following_count: i64,
+        }
+        let rows = sqlx::query_as::<_, Row>(
+            "SELECT u.id, u.username, u.display_name, u.avatar_url, u.bio,
+             COUNT(DISTINCT t.id) AS thought_count,
+             COUNT(DISTINCT f1.follower_id) AS follower_count,
+             COUNT(DISTINCT f2.following_id) AS following_count
+             FROM users u
+             LEFT JOIN thoughts t ON t.user_id=u.id AND t.local=true
+             LEFT JOIN follows f1 ON f1.following_id=u.id AND f1.state='accepted'
+             LEFT JOIN follows f2 ON f2.follower_id=u.id AND f2.state='accepted'
+             WHERE u.local=true
+             GROUP BY u.id
+             ORDER BY u.username",
+        )
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()?;
+
+        Ok(rows
+            .into_iter()
+            .map(|r| UserSummary {
+                id: UserId::from_uuid(r.id),
+                username: r.username,
+                display_name: r.display_name,
+                avatar_url: r.avatar_url,
+                bio: r.bio,
+                thought_count: r.thought_count,
+                follower_count: r.follower_count,
+                following_count: r.following_count,
+            })
+            .collect())
+    }
+
+    async fn count(&self) -> Result<i64, DomainError> {
+        sqlx::query_scalar::<_, i64>("SELECT COUNT(*) FROM users WHERE local = true")
+            .fetch_one(&self.pool)
+            .await
+            .into_domain()
+    }
+
+    async fn list_paginated(&self, page: PageParams) -> Result<Paginated<UserSummary>, DomainError> {
+        #[derive(sqlx::FromRow)]
+        struct Row {
+            id: uuid::Uuid,
+            username: String,
+            display_name: Option<String>,
+            avatar_url: Option<String>,
+            bio: Option<String>,
+            thought_count: i64,
+            follower_count: i64,
+            following_count: i64,
+            total: i64,
+        }
+        let rows = sqlx::query_as::<_, Row>(
+            "SELECT u.id, u.username, u.display_name, u.avatar_url, u.bio,
+             COUNT(DISTINCT t.id) AS thought_count,
+             COUNT(DISTINCT f1.follower_id) AS follower_count,
+             COUNT(DISTINCT f2.following_id) AS following_count,
+             COUNT(*) OVER() AS total
+             FROM users u
+             LEFT JOIN thoughts t ON t.user_id=u.id AND t.local=true
+             LEFT JOIN follows f1 ON f1.following_id=u.id AND f1.state='accepted'
+             LEFT JOIN follows f2 ON f2.follower_id=u.id AND f2.state='accepted'
+             WHERE u.local=true
+             GROUP BY u.id
+             ORDER BY u.username
+             LIMIT $1 OFFSET $2",
+        )
+        .bind(page.limit())
+        .bind(page.offset())
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()?;
+
+        let total = rows.first().map(|r| r.total).unwrap_or(0);
+        let items = rows
+            .into_iter()
+            .map(|r| UserSummary {
+                id: UserId::from_uuid(r.id),
+                username: r.username,
+                display_name: r.display_name,
+                avatar_url: r.avatar_url,
+                bio: r.bio,
+                thought_count: r.thought_count,
+                follower_count: r.follower_count,
+                following_count: r.following_count,
+            })
+            .collect();
+        Ok(Paginated { items, total, page: page.page, per_page: page.per_page })
+    }
+
+    async fn find_by_ids(&self, ids: &[UserId]) -> Result<HashMap<UserId, User>, DomainError> {
+        if ids.is_empty() {
+            return Ok(HashMap::new());
+        }
+        let uuids: Vec<uuid::Uuid> = ids.iter().map(|id| id.as_uuid()).collect();
+        let rows = sqlx::query_as::<_, UserRow>(
+            &format!("{USER_SELECT} WHERE id = ANY($1)")
+        )
+        .bind(&uuids[..])
+        .fetch_all(&self.pool)
+        .await
+        .into_domain()?;
+
+        Ok(rows.into_iter().map(|r| {
+            let user = User::from(r);
+            (user.id.clone(), user)
+        }).collect())
+    }
+}
+
+#[async_trait]
+impl UserWriter for PgUserRepository {
+    async fn save(&self, user: &User) -> Result<(), DomainError> {
+        sqlx::query(
+            "INSERT INTO users (id,username,email,password_hash,display_name,bio,avatar_url,header_url,custom_css,local,created_at,updated_at)
+             VALUES ($1,$2,$3,$4,$5,$6,$7,$8,$9,$10,$11,$12)
+             ON CONFLICT(id) DO UPDATE SET
+               username=EXCLUDED.username, email=EXCLUDED.email,
+               password_hash=EXCLUDED.password_hash, display_name=EXCLUDED.display_name,
+               bio=EXCLUDED.bio, avatar_url=EXCLUDED.avatar_url,
+               header_url=EXCLUDED.header_url, custom_css=EXCLUDED.custom_css,
+               local=EXCLUDED.local,
+               updated_at=NOW()"
+        )
+        .bind(user.id.as_uuid())
+        .bind(user.username.as_str())
+        .bind(user.email.as_str())
+        .bind(&user.password_hash.0)
+        .bind(&user.display_name)
+        .bind(&user.bio)
+        .bind(&user.avatar_url)
+        .bind(&user.header_url)
+        .bind(&user.custom_css)
+        .bind(user.local)
+        .bind(user.created_at)
+        .bind(user.updated_at)
+        .execute(&self.pool)
+        .await
+        .map_err(|e| {
+            if let sqlx::Error::Database(ref db) = e {
+                if db.code().as_deref() == Some("23505") {
+                    return match db.constraint().unwrap_or("") {
+                        "users_username_key" => DomainError::UniqueViolation { field: "username" },
+                        "users_email_key"    => DomainError::UniqueViolation { field: "email" },
+                        _                   => DomainError::UniqueViolation { field: "unknown" },
+                    };
+                }
+            }
+            DomainError::Internal(e.to_string())
+        })
+        .map(|_| ())
+    }
+
+    async fn update_profile(
+        &self,
+        user_id: &UserId,
+        display_name: Option<String>,
+        bio: Option<String>,
+        avatar_url: Option<String>,
+        header_url: Option<String>,
+        custom_css: Option<String>,
+    ) -> Result<(), DomainError> {
+        sqlx::query(
+            "UPDATE users SET display_name=$2,bio=$3,avatar_url=$4,header_url=$5,custom_css=$6,updated_at=NOW() WHERE id=$1"
+        )
+        .bind(user_id.as_uuid())
+        .bind(display_name)
+        .bind(bio)
+        .bind(avatar_url)
+        .bind(header_url)
+        .bind(custom_css)
+        .execute(&self.pool)
+        .await
+        .into_domain()
+        .map(|_| ())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use domain::{models::user::User, value_objects::*};
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn save_and_find_by_id(pool: sqlx::PgPool) {
+        let repo = PgUserRepository::new(pool);
+        let user = User::new_local(
+            UserId::new(),
+            Username::new("alice").unwrap(),
+            Email::new("alice@ex.com").unwrap(),
+            PasswordHash("hash".into()),
+        );
+        repo.save(&user).await.unwrap();
+        let found = repo.find_by_id(&user.id).await.unwrap().unwrap();
+        assert_eq!(found.username.as_str(), "alice");
+        assert_eq!(found.email.as_str(), "alice@ex.com");
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn find_by_username_returns_none_when_missing(pool: sqlx::PgPool) {
+        let repo = PgUserRepository::new(pool);
+        let result = repo
+            .find_by_username(&Username::new("ghost").unwrap())
+            .await
+            .unwrap();
+        assert!(result.is_none());
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn find_by_email(pool: sqlx::PgPool) {
+        let repo = PgUserRepository::new(pool);
+        let user = User::new_local(
+            UserId::new(),
+            Username::new("bob").unwrap(),
+            Email::new("bob@ex.com").unwrap(),
+            PasswordHash("hash".into()),
+        );
+        repo.save(&user).await.unwrap();
+        let found = repo
+            .find_by_email(&Email::new("bob@ex.com").unwrap())
+            .await
+            .unwrap();
+        assert!(found.is_some());
+    }
+
+    #[sqlx::test(migrations = "./migrations")]
+    async fn update_profile_changes_fields(pool: sqlx::PgPool) {
+        let repo = PgUserRepository::new(pool);
+        let user = User::new_local(
+            UserId::new(),
+            Username::new("charlie").unwrap(),
+            Email::new("charlie@ex.com").unwrap(),
+            PasswordHash("hash".into()),
+        );
+        repo.save(&user).await.unwrap();
+        repo.update_profile(
+            &user.id,
+            Some("Charlie".into()),
+            Some("bio".into()),
+            None,
+            None,
+            None,
+        )
+        .await
+        .unwrap();
+        let found = repo.find_by_id(&user.id).await.unwrap().unwrap();
+        assert_eq!(found.display_name.as_deref(), Some("Charlie"));
+        assert_eq!(found.bio.as_deref(), Some("bio"));
+    }
+}

crates/api-types/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "api-types"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+serde  = { workspace = true }
+uuid   = { workspace = true }
+chrono = { workspace = true }
+utoipa = { version = "5.5.0", features = ["uuid", "chrono"] }

crates/api-types/src/lib.rs

@@ -0,0 +1,2 @@
+pub mod requests;
+pub mod responses;

crates/api-types/src/requests.rs

@@ -0,0 +1,92 @@
+use serde::Deserialize;
+use uuid::Uuid;
+
+pub const DEFAULT_PAGE: u64 = 1;
+pub const DEFAULT_PER_PAGE: u64 = 20;
+pub const MAX_PER_PAGE: u64 = 100;
+
+#[derive(Deserialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct RegisterRequest {
+    /// Username (1-32 chars, alphanumeric + underscore)
+    pub username: String,
+    pub email: String,
+    pub password: String,
+}
+
+#[derive(Deserialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct LoginRequest {
+    pub email: String,
+    pub password: String,
+}
+
+#[derive(Deserialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct CreateThoughtRequest {
+    /// Up to 128 characters
+    pub content: String,
+    pub in_reply_to_id: Option<Uuid>,
+    /// One of: "public", "followers", "unlisted", "direct"
+    pub visibility: Option<String>,
+    pub content_warning: Option<String>,
+    pub sensitive: Option<bool>,
+}
+
+#[derive(Deserialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct EditThoughtRequest {
+    pub content: String,
+}
+
+#[derive(Deserialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct UpdateProfileRequest {
+    pub display_name: Option<String>,
+    pub bio: Option<String>,
+    pub avatar_url: Option<String>,
+    pub header_url: Option<String>,
+    pub custom_css: Option<String>,
+}
+
+#[derive(Deserialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct SetTopFriendsRequest {
+    /// Ordered list of user UUIDs, max 8
+    pub friend_ids: Vec<Uuid>,
+}
+
+#[derive(Deserialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct CreateApiKeyRequest {
+    pub name: String,
+}
+
+#[derive(Deserialize, utoipa::IntoParams)]
+pub struct PaginationQuery {
+    pub page: Option<u64>,
+    pub per_page: Option<u64>,
+}
+
+impl PaginationQuery {
+    pub fn page(&self) -> u64 {
+        self.page.unwrap_or(DEFAULT_PAGE).max(DEFAULT_PAGE)
+    }
+
+    pub fn per_page(&self) -> u64 {
+        self.per_page.unwrap_or(DEFAULT_PER_PAGE).min(MAX_PER_PAGE)
+    }
+}
+
+#[derive(Deserialize, utoipa::IntoParams)]
+pub struct SearchQuery {
+    pub q: String,
+    pub page: Option<u64>,
+    pub per_page: Option<u64>,
+}
+
+#[derive(serde::Deserialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct NotificationUpdateRequest {
+    pub read: bool,
+}

crates/api-types/src/responses.rs

@@ -0,0 +1,137 @@
+use chrono::{DateTime, Utc};
+use serde::Serialize;
+use uuid::Uuid;
+
+#[derive(Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct AuthResponse {
+    pub token: String,
+    pub user: UserResponse,
+}
+
+#[derive(Serialize, Clone, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct UserResponse {
+    pub id: Uuid,
+    pub username: String,
+    pub display_name: Option<String>,
+    pub bio: Option<String>,
+    pub avatar_url: Option<String>,
+    pub header_url: Option<String>,
+    pub custom_css: Option<String>,
+    pub local: bool,
+    pub is_followed_by_viewer: bool,
+    #[serde(rename = "joinedAt")]
+    pub created_at: DateTime<Utc>,
+}
+
+#[derive(Serialize, Clone, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct ThoughtResponse {
+    pub id: Uuid,
+    pub content: String,
+    pub author: UserResponse,
+    #[serde(rename = "replyToId")]
+    pub in_reply_to_id: Option<Uuid>,
+    #[serde(rename = "replyToUrl", skip_serializing_if = "Option::is_none")]
+    pub in_reply_to_url: Option<String>,
+    pub visibility: String,
+    pub content_warning: Option<String>,
+    pub sensitive: bool,
+    pub like_count: i64,
+    pub boost_count: i64,
+    pub reply_count: i64,
+    pub liked_by_viewer: bool,
+    pub boosted_by_viewer: bool,
+    pub created_at: DateTime<Utc>,
+    pub updated_at: Option<DateTime<Utc>>,
+}
+
+#[derive(Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct PagedResponse<T: Serialize + utoipa::ToSchema> {
+    pub items: Vec<T>,
+    pub total: i64,
+    pub page: u64,
+    pub per_page: u64,
+}
+
+#[derive(Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct ApiKeyResponse {
+    pub id: Uuid,
+    pub name: String,
+    pub created_at: DateTime<Utc>,
+}
+
+#[derive(Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct NotificationResponse {
+    pub id: Uuid,
+    pub notification_type: String,
+    pub from_user: Option<UserResponse>,
+    pub thought_id: Option<Uuid>,
+    pub read: bool,
+    pub created_at: DateTime<Utc>,
+}
+
+#[derive(Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct TopFriendsResponse {
+    pub top_friends: Vec<UserResponse>,
+}
+
+#[derive(Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct ErrorResponse {
+    pub error: String,
+}
+
+#[derive(Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct CreatedApiKeyResponse {
+    pub id: Uuid,
+    pub name: String,
+    /// Raw API key — shown only once at creation
+    pub key: String,
+}
+
+#[derive(Serialize, Clone, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct ProfileField {
+    pub name: String,
+    pub value: String,
+}
+
+#[derive(Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct RemoteActorResponse {
+    pub handle: String,
+    pub display_name: Option<String>,
+    pub avatar_url: Option<String>,
+    pub url: String,
+    pub bio: Option<String>,
+    pub banner_url: Option<String>,
+    pub also_known_as: Option<String>,
+    pub outbox_url: Option<String>,
+    pub followers_url: Option<String>,
+    pub following_url: Option<String>,
+    pub attachment: Vec<ProfileField>,
+}
+
+#[derive(Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct ActorConnectionResponse {
+    pub handle: String,
+    pub display_name: Option<String>,
+    pub avatar_url: Option<String>,
+    pub url: String,
+}
+
+#[derive(Serialize, utoipa::ToSchema)]
+#[serde(rename_all = "camelCase")]
+pub struct ActorConnectionPageResponse {
+    pub items: Vec<ActorConnectionResponse>,
+    pub page: u32,
+    pub has_more: bool,
+}

crates/application/Cargo.toml

@@ -0,0 +1,21 @@
+[package]
+name = "application"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]
+domain           = { workspace = true }
+activitypub-base = { workspace = true }
+async-trait      = { workspace = true }
+thiserror   = { workspace = true }
+uuid        = { workspace = true }
+chrono      = { workspace = true }
+sha2        = "0.10"
+hex         = "0.4"
+tracing     = { workspace = true }
+url         = { workspace = true }
+tokio       = { workspace = true }
+
+[dev-dependencies]
+tokio  = { workspace = true, features = ["full"] }
+domain = { workspace = true, features = ["test-helpers"] }

crates/application/src/lib.rs

@@ -0,0 +1,5 @@
+pub mod services;
+pub mod use_cases;
+
+#[cfg(test)]
+pub mod testing;

crates/application/src/services/federation_event.rs

@@ -0,0 +1,787 @@
+use activitypub_base::{ActivityPubRepository, OutboundFederationPort};
+use domain::{
+    errors::DomainError,
+    events::DomainEvent,
+    models::thought::Visibility,
+    ports::{ThoughtRepository, UserReader},
+    value_objects::ThoughtId,
+};
+use std::sync::Arc;
+
+pub struct FederationEventService {
+    pub thoughts: Arc<dyn ThoughtRepository>,
+    pub users: Arc<dyn UserReader>,
+    pub ap: Arc<dyn OutboundFederationPort>,
+    pub base_url: String,
+    pub ap_repo: Arc<dyn ActivityPubRepository>,
+}
+
+impl FederationEventService {
+    async fn object_ap_id(&self, thought_id: &ThoughtId) -> Result<String, DomainError> {
+        if let Some(ap_id) = self.ap_repo.get_thought_ap_id(thought_id).await? {
+            return Ok(ap_id);
+        }
+        Ok(format!("{}/thoughts/{}", self.base_url, thought_id))
+    }
+
+    pub async fn process(&self, event: &DomainEvent) -> Result<(), DomainError> {
+        match event {
+            DomainEvent::ThoughtCreated {
+                thought_id,
+                user_id,
+                ..
+            } => {
+                let thought = match self.thoughts.find_by_id(thought_id).await? {
+                    Some(t)
+                        if t.local
+                            && matches!(
+                                t.visibility,
+                                Visibility::Public | Visibility::Unlisted
+                            ) =>
+                    {
+                        t
+                    }
+                    _ => return Ok(()),
+                };
+                let user = match self.users.find_by_id(user_id).await? {
+                    Some(u) => u,
+                    None => return Ok(()),
+                };
+                // Resolve in_reply_to_url for the parent thought via AP repo.
+                let in_reply_to_url = if let Some(ref reply_id) = thought.in_reply_to_id {
+                    let ap_id = self
+                        .ap_repo
+                        .get_thought_ap_id(reply_id)
+                        .await?
+                        .unwrap_or_else(|| format!("{}/thoughts/{}", self.base_url, reply_id));
+                    Some(ap_id)
+                } else {
+                    None
+                };
+                self.ap
+                    .broadcast_create(
+                        user_id,
+                        &thought,
+                        user.username.as_str(),
+                        in_reply_to_url.as_deref(),
+                    )
+                    .await
+            }
+
+            DomainEvent::ThoughtDeleted {
+                thought_id,
+                user_id,
+            } => {
+                // No DB lookup — thought is already deleted when this event fires.
+                // No locality guard: delete commands only reach local thoughts via the use case.
+                let ap_id = format!("{}/thoughts/{}", self.base_url, thought_id);
+                self.ap.broadcast_delete(user_id, &ap_id).await
+            }
+
+            DomainEvent::ThoughtUpdated {
+                thought_id,
+                user_id,
+            } => {
+                let thought = match self.thoughts.find_by_id(thought_id).await? {
+                    Some(t)
+                        if t.local
+                            && matches!(
+                                t.visibility,
+                                Visibility::Public | Visibility::Unlisted
+                            ) =>
+                    {
+                        t
+                    }
+                    _ => return Ok(()),
+                };
+                let user = match self.users.find_by_id(user_id).await? {
+                    Some(u) => u,
+                    None => return Ok(()),
+                };
+                let in_reply_to_url = if let Some(ref reply_id) = thought.in_reply_to_id {
+                    self.ap_repo
+                        .get_thought_ap_id(reply_id)
+                        .await?
+                        .or_else(|| Some(format!("{}/thoughts/{}", self.base_url, reply_id)))
+                } else {
+                    None
+                };
+                self.ap
+                    .broadcast_update(
+                        user_id,
+                        &thought,
+                        user.username.as_str(),
+                        in_reply_to_url.as_deref(),
+                    )
+                    .await
+            }
+
+            DomainEvent::BoostAdded {
+                boost_id: _,
+                user_id,
+                thought_id,
+            } => {
+                // Only fan-out if the booster is a local user. Remote boosts must not be re-broadcast.
+                let booster = match self.users.find_by_id(user_id).await? {
+                    Some(u) if u.local => u,
+                    _ => return Ok(()),
+                };
+                let _ = booster;
+                if self.thoughts.find_by_id(thought_id).await?.is_none() {
+                    return Ok(());
+                }
+                let object_ap_id = self.object_ap_id(thought_id).await?;
+                self.ap.broadcast_announce(user_id, &object_ap_id).await
+            }
+
+            DomainEvent::BoostRemoved {
+                user_id,
+                thought_id,
+            } => {
+                if self.thoughts.find_by_id(thought_id).await?.is_none() {
+                    return Ok(());
+                }
+                let object_ap_id = self.object_ap_id(thought_id).await?;
+                self.ap
+                    .broadcast_undo_announce(user_id, &object_ap_id)
+                    .await
+            }
+
+            DomainEvent::LikeAdded {
+                like_id: _,
+                user_id,
+                thought_id,
+            } => {
+                // Only federate: local liker + remote thought (has ap_id) + author has inbox.
+                let liker = match self.users.find_by_id(user_id).await? {
+                    Some(u) if u.local => u,
+                    _ => return Ok(()),
+                };
+                let _ = liker;
+                let thought = match self.thoughts.find_by_id(thought_id).await? {
+                    Some(t) => t,
+                    _ => return Ok(()),
+                };
+                let thought_ap_id = match self.ap_repo.get_thought_ap_id(thought_id).await? {
+                    Some(id) => id,
+                    None => return Ok(()), // local thought — no federation needed
+                };
+                let actor_urls = match self.ap_repo.get_actor_ap_urls(&thought.user_id).await? {
+                    Some(u) => u,
+                    None => return Ok(()),
+                };
+                self.ap
+                    .broadcast_like(user_id, &thought_ap_id, &actor_urls.inbox_url)
+                    .await
+            }
+
+            DomainEvent::LikeRemoved {
+                user_id,
+                thought_id,
+            } => {
+                let liker = match self.users.find_by_id(user_id).await? {
+                    Some(u) if u.local => u,
+                    _ => return Ok(()),
+                };
+                let _ = liker;
+                let thought = match self.thoughts.find_by_id(thought_id).await? {
+                    Some(t) => t,
+                    _ => return Ok(()),
+                };
+                let thought_ap_id = match self.ap_repo.get_thought_ap_id(thought_id).await? {
+                    Some(id) => id,
+                    None => return Ok(()),
+                };
+                let actor_urls = match self.ap_repo.get_actor_ap_urls(&thought.user_id).await? {
+                    Some(u) => u,
+                    None => return Ok(()),
+                };
+                self.ap
+                    .broadcast_undo_like(user_id, &thought_ap_id, &actor_urls.inbox_url)
+                    .await
+            }
+
+            DomainEvent::ProfileUpdated { user_id } => {
+                self.ap.broadcast_actor_update(user_id).await
+            }
+
+            _ => Ok(()),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use activitypub_base::{ActorApUrls, OutboundFederationPort};
+    use async_trait::async_trait;
+    use crate::testing::TestApRepo;
+    use domain::{
+        errors::DomainError,
+        events::DomainEvent,
+        models::thought::{Thought, Visibility},
+        models::user::User,
+        testing::TestStore,
+        value_objects::*,
+    };
+    use std::sync::{Arc, Mutex};
+
+    // ── Spy port ─────────────────────────────────────────────────────────────
+
+    #[derive(Default)]
+    struct SpyPort {
+        created: Mutex<Vec<ThoughtId>>,
+        deleted: Mutex<Vec<String>>,
+        updated: Mutex<Vec<ThoughtId>>,
+        announced: Mutex<Vec<String>>,
+        undo_announced: Mutex<Vec<String>>,
+        liked: Mutex<Vec<String>>,
+        undo_liked: Mutex<Vec<String>>,
+        actor_updated: Mutex<Vec<UserId>>,
+    }
+
+    #[async_trait]
+    impl OutboundFederationPort for SpyPort {
+        async fn broadcast_create(
+            &self,
+            _: &UserId,
+            thought: &Thought,
+            _: &str,
+            _in_reply_to_url: Option<&str>,
+        ) -> Result<(), DomainError> {
+            self.created.lock().unwrap().push(thought.id.clone());
+            Ok(())
+        }
+        async fn broadcast_delete(&self, _: &UserId, ap_id: &str) -> Result<(), DomainError> {
+            self.deleted.lock().unwrap().push(ap_id.to_string());
+            Ok(())
+        }
+        async fn broadcast_update(
+            &self,
+            _: &UserId,
+            thought: &Thought,
+            _: &str,
+            _in_reply_to_url: Option<&str>,
+        ) -> Result<(), DomainError> {
+            self.updated.lock().unwrap().push(thought.id.clone());
+            Ok(())
+        }
+        async fn broadcast_announce(&self, _: &UserId, ap_id: &str) -> Result<(), DomainError> {
+            self.announced.lock().unwrap().push(ap_id.to_string());
+            Ok(())
+        }
+        async fn broadcast_undo_announce(
+            &self,
+            _: &UserId,
+            ap_id: &str,
+        ) -> Result<(), DomainError> {
+            self.undo_announced.lock().unwrap().push(ap_id.to_string());
+            Ok(())
+        }
+
+        async fn broadcast_like(
+            &self,
+            _: &UserId,
+            ap_id: &str,
+            _: &str,
+        ) -> Result<(), DomainError> {
+            self.liked.lock().unwrap().push(ap_id.to_string());
+            Ok(())
+        }
+
+        async fn broadcast_undo_like(
+            &self,
+            _: &UserId,
+            ap_id: &str,
+            _: &str,
+        ) -> Result<(), DomainError> {
+            self.undo_liked.lock().unwrap().push(ap_id.to_string());
+            Ok(())
+        }
+
+        async fn broadcast_actor_update(&self, user_id: &UserId) -> Result<(), DomainError> {
+            self.actor_updated.lock().unwrap().push(user_id.clone());
+            Ok(())
+        }
+    }
+
+    fn alice() -> User {
+        User::new_local(
+            UserId::new(),
+            Username::new("alice").unwrap(),
+            Email::new("alice@ex.com").unwrap(),
+            PasswordHash("h".into()),
+        )
+    }
+
+    fn local_thought(author_id: UserId) -> Thought {
+        Thought::new_local(
+            ThoughtId::new(),
+            author_id,
+            Content::new_local("hello").unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        )
+    }
+
+    fn svc(store: &TestStore, spy: Arc<SpyPort>) -> FederationEventService {
+        let ap_repo = TestApRepo::new(store.clone());
+        FederationEventService {
+            thoughts: Arc::new(store.clone()),
+            users: Arc::new(store.clone()),
+            ap: spy,
+            base_url: "https://example.com".to_string(),
+            ap_repo: Arc::new(ap_repo),
+        }
+    }
+
+    fn svc_with_ap(store: &TestStore, ap_repo: TestApRepo, spy: Arc<SpyPort>) -> FederationEventService {
+        FederationEventService {
+            thoughts: Arc::new(store.clone()),
+            users: Arc::new(store.clone()),
+            ap: spy,
+            base_url: "https://example.com".to_string(),
+            ap_repo: Arc::new(ap_repo),
+        }
+    }
+
+    #[tokio::test]
+    async fn thought_created_broadcasts_create() {
+        let store = TestStore::default();
+        let alice = alice();
+        let thought = local_thought(alice.id.clone());
+        store.users.lock().unwrap().push(alice.clone());
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::ThoughtCreated {
+                thought_id: thought.id.clone(),
+                user_id: alice.id.clone(),
+                in_reply_to_id: None,
+            })
+            .await
+            .unwrap();
+
+        assert_eq!(spy.created.lock().unwrap().len(), 1);
+        assert_eq!(spy.created.lock().unwrap()[0], thought.id);
+    }
+
+    #[tokio::test]
+    async fn remote_thought_created_does_not_broadcast() {
+        let store = TestStore::default();
+        let alice = alice();
+        // Remote thought: local = false
+        let mut thought = local_thought(alice.id.clone());
+        thought.local = false;
+        store.users.lock().unwrap().push(alice.clone());
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::ThoughtCreated {
+                thought_id: thought.id.clone(),
+                user_id: alice.id.clone(),
+                in_reply_to_id: None,
+            })
+            .await
+            .unwrap();
+
+        assert!(spy.created.lock().unwrap().is_empty());
+    }
+
+    #[tokio::test]
+    async fn thought_deleted_broadcasts_delete_with_constructed_ap_id() {
+        let store = TestStore::default();
+        let alice = alice();
+        let tid = ThoughtId::new();
+
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::ThoughtDeleted {
+                thought_id: tid.clone(),
+                user_id: alice.id.clone(),
+            })
+            .await
+            .unwrap();
+
+        let deleted = spy.deleted.lock().unwrap();
+        assert_eq!(deleted.len(), 1);
+        assert_eq!(deleted[0], format!("https://example.com/thoughts/{}", tid));
+    }
+
+    #[tokio::test]
+    async fn thought_updated_broadcasts_update() {
+        let store = TestStore::default();
+        let alice = alice();
+        let thought = local_thought(alice.id.clone());
+        store.users.lock().unwrap().push(alice.clone());
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::ThoughtUpdated {
+                thought_id: thought.id.clone(),
+                user_id: alice.id.clone(),
+            })
+            .await
+            .unwrap();
+
+        assert_eq!(spy.updated.lock().unwrap().len(), 1);
+        assert_eq!(spy.updated.lock().unwrap()[0], thought.id);
+    }
+
+    #[tokio::test]
+    async fn boost_of_local_thought_announces_constructed_url() {
+        let store = TestStore::default();
+        let alice = alice();
+        let thought = local_thought(alice.id.clone()); // ap_id = None
+        store.users.lock().unwrap().push(alice.clone());
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::BoostAdded {
+                boost_id: BoostId::new(),
+                user_id: alice.id.clone(),
+                thought_id: thought.id.clone(),
+            })
+            .await
+            .unwrap();
+
+        let announced = spy.announced.lock().unwrap();
+        assert_eq!(announced.len(), 1);
+        assert_eq!(
+            announced[0],
+            format!("https://example.com/thoughts/{}", thought.id)
+        );
+    }
+
+    #[tokio::test]
+    async fn boost_of_remote_thought_announces_remote_ap_id() {
+        let store = TestStore::default();
+        let alice = alice();
+        let mut thought = local_thought(alice.id.clone());
+        thought.local = false;
+        let ap_repo = TestApRepo::new(store.clone());
+        ap_repo.inner.thought_ap_ids.lock().unwrap().insert(
+            thought.id.clone(),
+            "https://mastodon.social/users/bob/statuses/123".into(),
+        );
+        store.users.lock().unwrap().push(alice.clone());
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc_with_ap(&store, ap_repo, spy.clone())
+            .process(&DomainEvent::BoostAdded {
+                boost_id: BoostId::new(),
+                user_id: alice.id.clone(),
+                thought_id: thought.id.clone(),
+            })
+            .await
+            .unwrap();
+
+        let announced = spy.announced.lock().unwrap();
+        assert_eq!(
+            announced[0],
+            "https://mastodon.social/users/bob/statuses/123"
+        );
+    }
+
+    #[tokio::test]
+    async fn direct_thought_created_does_not_broadcast() {
+        let store = TestStore::default();
+        let alice = alice();
+        let thought = Thought::new_local(
+            ThoughtId::new(),
+            alice.id.clone(),
+            Content::new_local("private").unwrap(),
+            None,
+            Visibility::Direct,
+            None,
+            false,
+        );
+        store.users.lock().unwrap().push(alice.clone());
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::ThoughtCreated {
+                thought_id: thought.id.clone(),
+                user_id: alice.id.clone(),
+                in_reply_to_id: None,
+            })
+            .await
+            .unwrap();
+
+        assert!(spy.created.lock().unwrap().is_empty());
+    }
+
+    #[tokio::test]
+    async fn followers_only_thought_does_not_broadcast_publicly() {
+        let store = TestStore::default();
+        let alice = alice();
+        let thought = Thought::new_local(
+            ThoughtId::new(),
+            alice.id.clone(),
+            Content::new_local("for followers").unwrap(),
+            None,
+            Visibility::Followers,
+            None,
+            false,
+        );
+        store.users.lock().unwrap().push(alice.clone());
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::ThoughtCreated {
+                thought_id: thought.id.clone(),
+                user_id: alice.id.clone(),
+                in_reply_to_id: None,
+            })
+            .await
+            .unwrap();
+
+        assert!(spy.created.lock().unwrap().is_empty());
+    }
+
+    #[tokio::test]
+    async fn unrelated_events_are_noop() {
+        let store = TestStore::default();
+        let spy = Arc::new(SpyPort::default());
+        let svc = svc(&store, spy.clone());
+
+        svc.process(&DomainEvent::UserBlocked {
+            blocker_id: UserId::new(),
+            blocked_id: UserId::new(),
+        })
+        .await
+        .unwrap();
+
+        assert!(spy.created.lock().unwrap().is_empty());
+        assert!(spy.deleted.lock().unwrap().is_empty());
+        assert!(spy.updated.lock().unwrap().is_empty());
+        assert!(spy.announced.lock().unwrap().is_empty());
+    }
+
+    #[tokio::test]
+    async fn thought_created_does_not_broadcast_if_user_missing() {
+        let store = TestStore::default();
+        let alice = alice();
+        let thought = local_thought(alice.id.clone());
+        // Don't push alice into users — simulates user deleted before handler runs
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::ThoughtCreated {
+                thought_id: thought.id.clone(),
+                user_id: alice.id.clone(),
+                in_reply_to_id: None,
+            })
+            .await
+            .unwrap();
+
+        assert!(spy.created.lock().unwrap().is_empty());
+    }
+
+    #[tokio::test]
+    async fn boost_removed_sends_undo_announce_for_local_thought() {
+        let store = TestStore::default();
+        let alice = alice();
+        let thought = local_thought(alice.id.clone()); // ap_id = None → constructed URL
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::BoostRemoved {
+                user_id: alice.id.clone(),
+                thought_id: thought.id.clone(),
+            })
+            .await
+            .unwrap();
+
+        let undo_announced = spy.undo_announced.lock().unwrap();
+        assert_eq!(undo_announced.len(), 1);
+        assert_eq!(
+            undo_announced[0],
+            format!("https://example.com/thoughts/{}", thought.id)
+        );
+    }
+
+    #[tokio::test]
+    async fn boost_removed_sends_undo_announce_for_remote_thought() {
+        let store = TestStore::default();
+        let alice = alice();
+        let mut thought = local_thought(alice.id.clone());
+        thought.local = false;
+        let ap_repo = TestApRepo::new(store.clone());
+        ap_repo.inner.thought_ap_ids.lock().unwrap().insert(
+            thought.id.clone(),
+            "https://mastodon.social/users/bob/statuses/456".into(),
+        );
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc_with_ap(&store, ap_repo, spy.clone())
+            .process(&DomainEvent::BoostRemoved {
+                user_id: alice.id.clone(),
+                thought_id: thought.id.clone(),
+            })
+            .await
+            .unwrap();
+
+        let undo_announced = spy.undo_announced.lock().unwrap();
+        assert_eq!(undo_announced.len(), 1);
+        assert_eq!(
+            undo_announced[0],
+            "https://mastodon.social/users/bob/statuses/456"
+        );
+    }
+
+    #[tokio::test]
+    async fn boost_removed_does_not_broadcast_if_thought_missing() {
+        let store = TestStore::default();
+        let alice = alice();
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::BoostRemoved {
+                user_id: alice.id.clone(),
+                thought_id: ThoughtId::new(), // doesn't exist in store
+            })
+            .await
+            .unwrap();
+        assert!(spy.undo_announced.lock().unwrap().is_empty());
+    }
+
+    #[tokio::test]
+    async fn thought_updated_does_not_broadcast_if_user_missing() {
+        let store = TestStore::default();
+        let alice = alice();
+        let thought = local_thought(alice.id.clone());
+        // Don't push alice into users
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::ThoughtUpdated {
+                thought_id: thought.id.clone(),
+                user_id: alice.id.clone(),
+            })
+            .await
+            .unwrap();
+
+        assert!(spy.updated.lock().unwrap().is_empty());
+    }
+
+    #[tokio::test]
+    async fn like_added_local_user_remote_thought_broadcasts_like() {
+        let store = TestStore::default();
+
+        let mut author = User::new_local(
+            UserId::new(),
+            Username::new("remote_author").unwrap(),
+            Email::new("r@remote.example").unwrap(),
+            PasswordHash("h".into()),
+        );
+        author.local = false;
+        let thought = local_thought(author.id.clone());
+        let liker = alice();
+
+        store.users.lock().unwrap().push(author.clone());
+        store.users.lock().unwrap().push(liker.clone());
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let ap_repo = TestApRepo::new(store.clone());
+        ap_repo.actor_ap_urls.lock().unwrap().insert(
+            author.id.clone(),
+            ActorApUrls {
+                ap_id: "https://mastodon.social/users/author".into(),
+                inbox_url: "https://mastodon.social/users/author/inbox".into(),
+            },
+        );
+        ap_repo.inner.thought_ap_ids.lock().unwrap().insert(
+            thought.id.clone(),
+            "https://mastodon.social/posts/123".into(),
+        );
+
+        let spy = Arc::new(SpyPort::default());
+        svc_with_ap(&store, ap_repo, spy.clone())
+            .process(&DomainEvent::LikeAdded {
+                like_id: LikeId::new(),
+                user_id: liker.id,
+                thought_id: thought.id,
+            })
+            .await
+            .unwrap();
+
+        assert_eq!(spy.liked.lock().unwrap().len(), 1);
+    }
+
+    #[tokio::test]
+    async fn like_added_remote_user_skips_broadcast() {
+        let store = TestStore::default();
+
+        let author = alice();
+        let thought = local_thought(author.id.clone()); // local thought — no ap_id
+
+        let mut remote_liker = User::new_local(
+            UserId::new(),
+            Username::new("bob").unwrap(),
+            Email::new("bob@remote").unwrap(),
+            PasswordHash("h".into()),
+        );
+        remote_liker.local = false;
+
+        store.users.lock().unwrap().push(author);
+        store.users.lock().unwrap().push(remote_liker.clone());
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::LikeAdded {
+                like_id: LikeId::new(),
+                user_id: remote_liker.id,
+                thought_id: thought.id,
+            })
+            .await
+            .unwrap();
+
+        assert!(spy.liked.lock().unwrap().is_empty());
+    }
+
+    #[tokio::test]
+    async fn boost_added_remote_user_skips_broadcast() {
+        let store = TestStore::default();
+
+        let author = alice();
+        let thought = local_thought(author.id.clone());
+
+        let mut remote_booster = User::new_local(
+            UserId::new(),
+            Username::new("bob").unwrap(),
+            Email::new("bob@remote").unwrap(),
+            PasswordHash("h".into()),
+        );
+        remote_booster.local = false;
+
+        store.users.lock().unwrap().push(author);
+        store.users.lock().unwrap().push(remote_booster.clone());
+        store.thoughts.lock().unwrap().push(thought.clone());
+
+        let spy = Arc::new(SpyPort::default());
+        svc(&store, spy.clone())
+            .process(&DomainEvent::BoostAdded {
+                boost_id: BoostId::new(),
+                user_id: remote_booster.id,
+                thought_id: thought.id,
+            })
+            .await
+            .unwrap();
+
+        assert!(spy.announced.lock().unwrap().is_empty());
+    }
+}

crates/application/src/services/mod.rs

@@ -0,0 +1,5 @@
+pub mod federation_event;
+pub mod notification_event;
+
+pub use federation_event::FederationEventService;
+pub use notification_event::NotificationEventService;

crates/application/src/services/notification_event.rs

@@ -0,0 +1,332 @@
+use chrono::Utc;
+use domain::{
+    errors::DomainError,
+    events::DomainEvent,
+    models::notification::{Notification, NotificationKind},
+    ports::{NotificationRepository, ThoughtRepository},
+    value_objects::NotificationId,
+};
+use std::sync::Arc;
+
+pub struct NotificationEventService {
+    pub thoughts: Arc<dyn ThoughtRepository>,
+    pub notifications: Arc<dyn NotificationRepository>,
+}
+
+fn is_self_action(
+    thought_author: &domain::value_objects::UserId,
+    actor: &domain::value_objects::UserId,
+) -> bool {
+    thought_author == actor
+}
+
+impl NotificationEventService {
+    pub async fn process(&self, event: &DomainEvent) -> Result<(), DomainError> {
+        match event {
+            DomainEvent::LikeAdded {
+                like_id: _,
+                user_id,
+                thought_id,
+            } => {
+                let thought = match self.thoughts.find_by_id(thought_id).await? {
+                    Some(t) => t,
+                    None => return Ok(()),
+                };
+                if is_self_action(&thought.user_id, user_id) {
+                    return Ok(());
+                }
+                self.notifications
+                    .save(&Notification {
+                        id: NotificationId::new(),
+                        user_id: thought.user_id,
+                        kind: NotificationKind::Like {
+                            thought_id: thought_id.clone(),
+                            from_user_id: user_id.clone(),
+                        },
+                        read: false,
+                        created_at: Utc::now(),
+                    })
+                    .await
+            }
+            DomainEvent::BoostAdded {
+                boost_id: _,
+                user_id,
+                thought_id,
+            } => {
+                let thought = match self.thoughts.find_by_id(thought_id).await? {
+                    Some(t) => t,
+                    None => return Ok(()),
+                };
+                if is_self_action(&thought.user_id, user_id) {
+                    return Ok(());
+                }
+                self.notifications
+                    .save(&Notification {
+                        id: NotificationId::new(),
+                        user_id: thought.user_id,
+                        kind: NotificationKind::Boost {
+                            thought_id: thought_id.clone(),
+                            from_user_id: user_id.clone(),
+                        },
+                        read: false,
+                        created_at: Utc::now(),
+                    })
+                    .await
+            }
+            DomainEvent::FollowAccepted {
+                follower_id,
+                following_id,
+            } => {
+                self.notifications
+                    .save(&Notification {
+                        id: NotificationId::new(),
+                        user_id: following_id.clone(),
+                        kind: NotificationKind::Follow {
+                            from_user_id: follower_id.clone(),
+                        },
+                        read: false,
+                        created_at: Utc::now(),
+                    })
+                    .await
+            }
+            DomainEvent::ThoughtCreated {
+                thought_id,
+                user_id,
+                in_reply_to_id,
+            } => {
+                let reply_to_id = match in_reply_to_id {
+                    Some(id) => id,
+                    None => return Ok(()),
+                };
+                let original = match self.thoughts.find_by_id(reply_to_id).await? {
+                    Some(t) => t,
+                    None => return Ok(()),
+                };
+                if is_self_action(&original.user_id, user_id) {
+                    return Ok(());
+                }
+                self.notifications
+                    .save(&Notification {
+                        id: NotificationId::new(),
+                        user_id: original.user_id,
+                        kind: NotificationKind::Reply {
+                            thought_id: thought_id.clone(),
+                            from_user_id: user_id.clone(),
+                        },
+                        read: false,
+                        created_at: Utc::now(),
+                    })
+                    .await
+            }
+            DomainEvent::MentionReceived {
+                thought_id,
+                mentioned_user_id,
+                author_user_id,
+            } => {
+                self.notifications
+                    .save(&Notification {
+                        id: NotificationId::new(),
+                        user_id: mentioned_user_id.clone(),
+                        kind: NotificationKind::Mention {
+                            thought_id: thought_id.clone(),
+                            from_user_id: author_user_id.clone(),
+                        },
+                        read: false,
+                        created_at: Utc::now(),
+                    })
+                    .await
+            }
+            _ => Ok(()),
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use domain::{
+        models::{
+            notification::NotificationKind,
+            thought::{Thought, Visibility},
+            user::User,
+        },
+        testing::TestStore,
+        value_objects::*,
+    };
+    use std::sync::Arc;
+
+    fn alice() -> User {
+        User::new_local(
+            UserId::new(),
+            Username::new("alice").unwrap(),
+            Email::new("alice@ex.com").unwrap(),
+            PasswordHash("h".into()),
+        )
+    }
+
+    #[tokio::test]
+    async fn like_creates_notification_for_thought_author() {
+        let store = TestStore::default();
+        let alice = alice();
+        let bob_id = UserId::new();
+        let thought = Thought::new_local(
+            ThoughtId::new(),
+            alice.id.clone(),
+            Content::new_local("hello").unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        );
+        store.thoughts.lock().unwrap().push(thought.clone());
+        let svc = NotificationEventService {
+            thoughts: Arc::new(store.clone()),
+            notifications: Arc::new(store.clone()),
+        };
+        svc.process(&DomainEvent::LikeAdded {
+            like_id: LikeId::new(),
+            user_id: bob_id,
+            thought_id: thought.id.clone(),
+        })
+        .await
+        .unwrap();
+        let notifs = store.notifications.lock().unwrap();
+        assert_eq!(notifs.len(), 1);
+        assert!(matches!(notifs[0].kind, NotificationKind::Like { .. }));
+    }
+
+    #[tokio::test]
+    async fn self_like_creates_no_notification() {
+        let store = TestStore::default();
+        let alice = alice();
+        let thought = Thought::new_local(
+            ThoughtId::new(),
+            alice.id.clone(),
+            Content::new_local("hello").unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        );
+        store.thoughts.lock().unwrap().push(thought.clone());
+        let svc = NotificationEventService {
+            thoughts: Arc::new(store.clone()),
+            notifications: Arc::new(store.clone()),
+        };
+        svc.process(&DomainEvent::LikeAdded {
+            like_id: LikeId::new(),
+            user_id: alice.id.clone(),
+            thought_id: thought.id.clone(),
+        })
+        .await
+        .unwrap();
+        assert!(store.notifications.lock().unwrap().is_empty());
+    }
+
+    #[tokio::test]
+    async fn follow_accepted_creates_notification() {
+        let store = TestStore::default();
+        let alice = alice();
+        let bob_id = UserId::new();
+        let svc = NotificationEventService {
+            thoughts: Arc::new(store.clone()),
+            notifications: Arc::new(store.clone()),
+        };
+        svc.process(&DomainEvent::FollowAccepted {
+            follower_id: bob_id,
+            following_id: alice.id.clone(),
+        })
+        .await
+        .unwrap();
+        let notifs = store.notifications.lock().unwrap();
+        assert_eq!(notifs.len(), 1);
+        assert!(matches!(notifs[0].kind, NotificationKind::Follow { .. }));
+    }
+
+    #[tokio::test]
+    async fn reply_creates_notification_for_original_author() {
+        let store = TestStore::default();
+        let alice = alice();
+        let bob_id = UserId::new();
+        let original = Thought::new_local(
+            ThoughtId::new(),
+            alice.id.clone(),
+            Content::new_local("original").unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        );
+        store.thoughts.lock().unwrap().push(original.clone());
+        let svc = NotificationEventService {
+            thoughts: Arc::new(store.clone()),
+            notifications: Arc::new(store.clone()),
+        };
+        svc.process(&DomainEvent::ThoughtCreated {
+            thought_id: ThoughtId::new(),
+            user_id: bob_id,
+            in_reply_to_id: Some(original.id.clone()),
+        })
+        .await
+        .unwrap();
+        let notifs = store.notifications.lock().unwrap();
+        assert_eq!(notifs.len(), 1);
+        assert!(matches!(notifs[0].kind, NotificationKind::Reply { .. }));
+    }
+
+    #[tokio::test]
+    async fn self_reply_creates_no_notification() {
+        let store = TestStore::default();
+        let alice = alice();
+        let original = Thought::new_local(
+            ThoughtId::new(),
+            alice.id.clone(),
+            Content::new_local("original").unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        );
+        store.thoughts.lock().unwrap().push(original.clone());
+        let svc = NotificationEventService {
+            thoughts: Arc::new(store.clone()),
+            notifications: Arc::new(store.clone()),
+        };
+        svc.process(&DomainEvent::ThoughtCreated {
+            thought_id: ThoughtId::new(),
+            user_id: alice.id.clone(),
+            in_reply_to_id: Some(original.id.clone()),
+        })
+        .await
+        .unwrap();
+        assert!(store.notifications.lock().unwrap().is_empty());
+    }
+
+    #[tokio::test]
+    async fn self_boost_creates_no_notification() {
+        let store = TestStore::default();
+        let alice = alice();
+        let thought = Thought::new_local(
+            ThoughtId::new(),
+            alice.id.clone(),
+            Content::new_local("hello").unwrap(),
+            None,
+            Visibility::Public,
+            None,
+            false,
+        );
+        store.thoughts.lock().unwrap().push(thought.clone());
+        let svc = NotificationEventService {
+            thoughts: Arc::new(store.clone()),
+            notifications: Arc::new(store.clone()),
+        };
+        svc.process(&DomainEvent::BoostAdded {
+            boost_id: BoostId::new(),
+            user_id: alice.id.clone(),
+            thought_id: thought.id.clone(),
+        })
+        .await
+        .unwrap();
+        assert!(store.notifications.lock().unwrap().is_empty());
+    }
+}

crates/application/src/testing.rs

@@ -0,0 +1,150 @@
+/// Test helpers for application-layer tests that need activitypub_base traits.
+use activitypub_base::{ActivityPubRepository, ActorApUrls, OutboxEntry};
+use async_trait::async_trait;
+use domain::{
+    errors::DomainError,
+    models::user::User,
+    testing::TestStore,
+    value_objects::{Email, PasswordHash, ThoughtId, UserId, Username},
+};
+use std::collections::HashMap;
+use std::sync::{Arc, Mutex};
+
+/// Extends `TestStore` with AP-specific lookup maps.
+#[derive(Default, Clone)]
+pub struct TestApRepo {
+    pub inner: TestStore,
+    /// UserId → ActorApUrls (for get_actor_ap_urls)
+    pub actor_ap_urls: Arc<Mutex<HashMap<UserId, ActorApUrls>>>,
+}
+
+impl TestApRepo {
+    pub fn new(inner: TestStore) -> Self {
+        Self {
+            inner,
+            actor_ap_urls: Default::default(),
+        }
+    }
+}
+
+#[async_trait]
+impl ActivityPubRepository for TestApRepo {
+    async fn outbox_entries_for_actor(
+        &self,
+        _uid: &UserId,
+    ) -> Result<Vec<OutboxEntry>, DomainError> {
+        Ok(vec![])
+    }
+    async fn outbox_page_for_actor(
+        &self,
+        _uid: &UserId,
+        _before: Option<chrono::DateTime<chrono::Utc>>,
+        _limit: usize,
+    ) -> Result<Vec<OutboxEntry>, DomainError> {
+        Ok(vec![])
+    }
+    async fn find_remote_actor_id(
+        &self,
+        actor_ap_url: &str,
+    ) -> Result<Option<UserId>, DomainError> {
+        Ok(self
+            .inner
+            .actor_ap_ids
+            .lock()
+            .unwrap()
+            .get(actor_ap_url)
+            .cloned())
+    }
+    async fn intern_remote_actor(&self, actor_ap_url: &str) -> Result<UserId, DomainError> {
+        if let Some(uid) = self.find_remote_actor_id(actor_ap_url).await? {
+            return Ok(uid);
+        }
+        let uid = UserId::new();
+        let handle = url::Url::parse(actor_ap_url)
+            .map(|u| u.path().trim_start_matches('/').replace('/', "_"))
+            .unwrap_or_else(|_| format!("remote_{}", &uid.to_string()[..8]));
+        let user = User {
+            id: uid.clone(),
+            username: Username::from_trusted(handle),
+            email: Email::from_trusted(format!("{}@remote", uid)),
+            password_hash: PasswordHash("".into()),
+            display_name: None,
+            bio: None,
+            avatar_url: None,
+            header_url: None,
+            custom_css: None,
+            local: false,
+            created_at: chrono::Utc::now(),
+            updated_at: chrono::Utc::now(),
+        };
+        self.inner.users.lock().unwrap().push(user);
+        self.inner
+            .actor_ap_ids
+            .lock()
+            .unwrap()
+            .insert(actor_ap_url.to_string(), uid.clone());
+        Ok(uid)
+    }
+    async fn update_remote_actor_display(
+        &self,
+        _user_id: &UserId,
+        _display_name: Option<&str>,
+        _avatar_url: Option<&str>,
+    ) -> Result<(), DomainError> {
+        Ok(())
+    }
+    async fn accept_note(
+        &self,
+        _ap_id: &str,
+        _author_id: &UserId,
+        _content: &str,
+        _published: chrono::DateTime<chrono::Utc>,
+        _sensitive: bool,
+        _content_warning: Option<String>,
+        _visibility: &str,
+        _in_reply_to: Option<&str>,
+    ) -> Result<ThoughtId, DomainError> {
+        Ok(ThoughtId::from_uuid(uuid::Uuid::new_v4()))
+    }
+    async fn apply_note_update(
+        &self,
+        _ap_id: &str,
+        _new_content: &str,
+    ) -> Result<(), DomainError> {
+        Ok(())
+    }
+    async fn retract_note(&self, _ap_id: &str) -> Result<(), DomainError> {
+        Ok(())
+    }
+    async fn retract_actor_notes(&self, _actor_ap_url: &str) -> Result<(), DomainError> {
+        Ok(())
+    }
+    async fn count_local_notes(&self) -> Result<u64, DomainError> {
+        Ok(self
+            .inner
+            .thoughts
+            .lock()
+            .unwrap()
+            .iter()
+            .filter(|t| t.local)
+            .count() as u64)
+    }
+    async fn get_thought_ap_id(
+        &self,
+        thought_id: &ThoughtId,
+    ) -> Result<Option<String>, DomainError> {
+        Ok(self
+            .inner
+            .thought_ap_ids
+            .lock()
+            .unwrap()
+            .get(thought_id)
+            .cloned())
+    }
+    async fn get_actor_ap_urls(
+        &self,
+        user_id: &UserId,
+    ) -> Result<Option<ActorApUrls>, DomainError> {
+        Ok(self.actor_ap_urls.lock().unwrap().get(user_id).cloned())
+    }
+}

crates/application/src/use_cases/api_keys.rs

@@ -0,0 +1,101 @@
+use chrono::Utc;
+use domain::{
+    errors::DomainError,
+    models::api_key::ApiKey,
+    ports::ApiKeyRepository,
+    value_objects::{ApiKeyId, UserId},
+};
+
+pub async fn list_api_keys(
+    keys: &dyn ApiKeyRepository,
+    user_id: &UserId,
+) -> Result<Vec<ApiKey>, DomainError> {
+    keys.list_for_user(user_id).await
+}
+
+pub async fn create_api_key(
+    keys: &dyn ApiKeyRepository,
+    user_id: &UserId,
+    name: String,
+) -> Result<(ApiKey, String), DomainError> {
+    let raw_key = uuid::Uuid::new_v4().to_string().replace('-', "");
+    let key_hash = sha256_hex(&raw_key);
+    let key = ApiKey {
+        id: ApiKeyId::new(),
+        user_id: user_id.clone(),
+        key_hash,
+        name,
+        created_at: Utc::now(),
+    };
+    keys.save(&key).await?;
+    Ok((key, raw_key))
+}
+
+pub async fn delete_api_key(
+    keys: &dyn ApiKeyRepository,
+    user_id: &UserId,
+    key_id: &ApiKeyId,
+) -> Result<(), DomainError> {
+    keys.delete(key_id, user_id).await
+}
+
+fn sha256_hex(s: &str) -> String {
+    use sha2::{Digest, Sha256};
+    let hash = Sha256::digest(s.as_bytes());
+    hex::encode(hash)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use domain::{testing::TestStore, value_objects::UserId};
+
+    #[tokio::test]
+    async fn create_key_saves_hashed_not_raw() {
+        let store = TestStore::default();
+        let uid = UserId::new();
+        let (key, raw) = create_api_key(&store, &uid, "my-key".to_string())
+            .await
+            .unwrap();
+        assert_ne!(key.key_hash, raw, "stored hash must differ from raw key");
+        assert!(!key.key_hash.is_empty());
+        assert_eq!(key.name, "my-key");
+        assert_eq!(key.user_id, uid);
+        assert_eq!(store.api_keys.lock().unwrap().len(), 1);
+    }
+
+    #[tokio::test]
+    async fn raw_key_verifies_against_stored_hash() {
+        use sha2::{Digest, Sha256};
+        let store = TestStore::default();
+        let uid = UserId::new();
+        let (key, raw) = create_api_key(&store, &uid, "test".to_string())
+            .await
+            .unwrap();
+        let expected_hash = hex::encode(Sha256::digest(raw.as_bytes()));
+        assert_eq!(key.key_hash, expected_hash);
+    }
+
+    #[tokio::test]
+    async fn delete_key_removes_it() {
+        let store = TestStore::default();
+        let uid = UserId::new();
+        let (key, _) = create_api_key(&store, &uid, "k".to_string()).await.unwrap();
+        delete_api_key(&store, &uid, &key.id).await.unwrap();
+        assert!(store.api_keys.lock().unwrap().is_empty());
+    }
+
+    #[tokio::test]
+    async fn list_keys_returns_only_own_keys() {
+        let store = TestStore::default();
+        let alice = UserId::new();
+        let bob = UserId::new();
+        create_api_key(&store, &alice, "a".to_string())
+            .await
+            .unwrap();
+        create_api_key(&store, &bob, "b".to_string()).await.unwrap();
+        let alice_keys = list_api_keys(&store, &alice).await.unwrap();
+        assert_eq!(alice_keys.len(), 1);
+        assert_eq!(alice_keys[0].user_id, alice);
+    }
+}