refactor: 5 architectural improvements (Tasks 2-5 + Task 6 fix)

- feat(domain): Hashtag value object with canonical extract() — unifies two divergent private implementations; fields pre-compute raw/normalized/url_slug/ap_name - feat(presentation): Deps<S: FromAppState> extractor — each handler now declares its exact dependency surface; AppState unchanged; handlers become unit-testable without mocking all 20 deps - refactor(feed): replace 5 flat FeedRepository methods with FeedQuery/FeedScope — single query() method; SQL shared logic lives once; adding feed types no longer requires 5 edits - refactor(activitypub): ActivityPubRepository + OutboundFederationPort moved out of domain::ports into activitypub-base::ap_ports — domain crate no longer knows about AP IDs, inboxes, or actor URLs - fix(outbox): OutboxRelay now opens a per-row transaction so FOR UPDATE SKIP LOCKED actually holds the lock during publish + mark_delivered
2026-05-15 18:54:20 +02:00
parent 6024a65060
commit 0592861edd
37 changed files with 1401 additions and 865 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -289,6 +289,7 @@ dependencies = [
 name = "application"
 version = "0.1.0"
 dependencies = [
+ "activitypub-base",
 "async-trait",
 "chrono",
 "domain",
@@ -2447,6 +2448,7 @@ checksum = "c33a9471896f1c69cecef8d20cbe2f7accd12527ce60845ff44c153bb2a21b49"
 name = "postgres"
 version = "0.1.0"
 dependencies = [
+ "activitypub-base",
 "async-trait",
 "chrono",
 "domain",
@@ -2516,6 +2518,7 @@ dependencies = [
 name = "presentation"
 version = "0.1.0"
 dependencies = [
+ "activitypub-base",
 "api-types",
 "application",
 "async-trait",
--- a/crates/adapters/activitypub-base/src/ap_ports.rs
+++ b/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<(), 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>;
+}
--- a/crates/adapters/activitypub-base/src/lib.rs
+++ b/crates/adapters/activitypub-base/src/lib.rs
@@ -1,6 +1,7 @@
 pub mod activities;
 pub mod actor_handler;
 pub mod actors;
+pub mod ap_ports;
 pub mod content;
 pub mod data;
 pub mod error;
@@ -17,6 +18,7 @@ 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;
--- a/crates/adapters/activitypub-base/src/service.rs
+++ b/crates/adapters/activitypub-base/src/service.rs
@@ -50,26 +50,6 @@ fn content_to_html(text: &str) -> String {
    }
 }

-fn extract_hashtag_tags(content: &str, base_url: &str) -> Vec<serde_json::Value> {
-    let mut seen = std::collections::HashSet::new();
-    let mut tags = Vec::new();
-    for word in content.split_whitespace() {
-        let tag = word.trim_matches(|c: char| !c.is_alphanumeric() && c != '#');
-        if let Some(name) = tag.strip_prefix('#')
-            && !name.is_empty()
-            && seen.insert(name.to_lowercase())
-        {
-            let lower = name.to_lowercase();
-            tags.push(serde_json::json!({
-                "type": "Hashtag",
-                "name": format!("#{}", lower),
-                "href": format!("{}/tags/{}", base_url, lower),
-            }));
-        }
-    }
-    tags
-}
-
 fn thought_note_json(
    thought: &domain::models::thought::Thought,
    local_actor: &crate::actors::DbActor,
@@ -114,9 +94,19 @@ fn thought_note_json(
    if let Some(updated_at) = thought.updated_at {
        note["updated"] = serde_json::json!(updated_at.to_rfc3339());
    }
-    let hashtag_tags = extract_hashtag_tags(thought.content.as_str(), base_url);
-    if !hashtag_tags.is_empty() {
-        note["tag"] = serde_json::json!(hashtag_tags);
+    let hashtags = domain::hashtag::extract(thought.content.as_str());
+    if !hashtags.is_empty() {
+        let ap_tags: Vec<serde_json::Value> = hashtags
+            .iter()
+            .map(|h| {
+                serde_json::json!({
+                    "type": "Hashtag",
+                    "name": h.ap_name,
+                    "href": format!("{}/{}", base_url, h.url_slug),
+                })
+            })
+            .collect();
+        note["tag"] = serde_json::json!(ap_tags);
    }
    Ok((ap_id, note))
 }
@@ -1405,7 +1395,7 @@ impl ActivityPubService {
 }

 #[async_trait::async_trait]
-impl domain::ports::OutboundFederationPort for ActivityPubService {
+impl crate::ap_ports::OutboundFederationPort for ActivityPubService {
    // Actor identity (ap_id, followers_url) comes from federation config via get_local_actor.
    // author_username is provided by the caller but not needed here.
    async fn broadcast_create(
--- a/crates/adapters/activitypub/src/handler.rs
+++ b/crates/adapters/activitypub/src/handler.rs
@@ -9,8 +9,8 @@ use url::Url;

 use crate::note::ThoughtNote;
 use crate::urls::ThoughtsUrls;
-use activitypub_base::ApObjectHandler;
-use domain::ports::{ActivityPubRepository, EventPublisher};
+use activitypub_base::{ActivityPubRepository, ApObjectHandler};
+use domain::ports::EventPublisher;
 use domain::value_objects::UserId;

 pub struct ThoughtsObjectHandler {
--- a/crates/adapters/postgres/Cargo.toml
+++ b/crates/adapters/postgres/Cargo.toml
@@ -4,9 +4,10 @@ version = "0.1.0"
 edition = "2021"

 [dependencies]
-domain        = { workspace = true }
-event-payload = { workspace = true }
-sqlx          = { workspace = true }
+domain           = { workspace = true }
+activitypub-base = { workspace = true }
+event-payload    = { workspace = true }
+sqlx             = { workspace = true }
 uuid        = { workspace = true }
 serde_json  = { workspace = true }
 chrono      = { workspace = true }
--- a/crates/adapters/postgres/src/activitypub.rs
+++ b/crates/adapters/postgres/src/activitypub.rs
@@ -6,10 +6,10 @@ 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},
-    ports::{ActivityPubRepository, ActorApUrls, OutboxEntry},
    value_objects::{Content, ThoughtId, UserId, Username},
 };

@@ -328,7 +328,7 @@ impl ActivityPubRepository for PgActivityPubRepository {
 #[cfg(test)]
 mod tests {
    use super::*;
-    use domain::ports::ActivityPubRepository;
+    use activitypub_base::ActivityPubRepository;

    #[sqlx::test(migrations = "./migrations")]
    async fn intern_remote_actor_is_idempotent(pool: sqlx::PgPool) {
--- a/crates/adapters/postgres/src/feed.rs
+++ b/crates/adapters/postgres/src/feed.rs
@@ -5,11 +5,11 @@ use chrono::{DateTime, Utc};
 use domain::{
    errors::DomainError,
    models::{
-        feed::{FeedEntry, PageParams, Paginated},
+        feed::{FeedEntry, Paginated},
        thought::{Thought, Visibility},
        user::User,
    },
-    ports::FeedRepository,
+    ports::{FeedQuery, FeedRepository, FeedScope},
    value_objects::{Content, Email, PasswordHash, ThoughtId, UserId, Username},
 };
 use sqlx::PgPool;
@@ -150,201 +150,178 @@ fn row_to_entry(r: FeedRow, viewer: Option<uuid::Uuid>) -> Result<FeedEntry, Dom

 #[async_trait]
 impl FeedRepository for PgFeedRepository {
-    async fn home_feed(
-        &self,
-        following_ids: &[UserId],
-        page: &PageParams,
-        viewer_id: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError> {
-        let ids: Vec<uuid::Uuid> = following_ids.iter().map(|id| id.as_uuid()).collect();
-        let viewer = viewer_id.map(|v| v.as_uuid());
-        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()?;
+    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;

-        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()?;
+        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()?;

-        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,
-        })
-    }
+                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()?;

-    async fn public_feed(
-        &self,
-        page: &PageParams,
-        viewer_id: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError> {
-        let viewer = viewer_id.map(|v| v.as_uuid());
-        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()?;
+                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,
+                })
+            }

-        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()?;
+            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()?;

-        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,
-        })
-    }
+                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()?;

-    async fn search(
-        &self,
-        query: &str,
-        page: &PageParams,
-        viewer_id: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError> {
-        let viewer = viewer_id.map(|v| v.as_uuid());
-        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()?;
+                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,
+                })
+            }

-        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()?;
+            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()?;

-        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,
-        })
-    }
+                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()?;

-    async fn tag_feed(
-        &self,
-        tag_name: &str,
-        page: &PageParams,
-        viewer_id: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError> {
-        let viewer = viewer_id.map(|v| v.as_uuid());
-        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()?;
+                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,
+                })
+            }

-        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()?;
+            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()?;

-        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,
-        })
-    }
+                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()?;

-    async fn user_feed(
-        &self,
-        user_id: &UserId,
-        page: &PageParams,
-        viewer_id: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError> {
-        let viewer = viewer_id.map(|v| v.as_uuid());
-        let uid = user_id.as_uuid();
+                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,
+                })
+            }

-        // Use nil UUID for unauthenticated viewers — won't match owner or follower checks.
-        let viewer_uuid = viewer.unwrap_or(uuid::Uuid::nil());
+            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 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()?;
+                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,
-        })
+                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,
+                })
+            }
+        }
    }
 }

@@ -354,10 +331,11 @@ mod tests {
    use crate::{thought::PgThoughtRepository, user::PgUserRepository};
    use domain::{
        models::{
+            feed::PageParams,
            thought::{Thought, Visibility},
            user::User,
        },
-        ports::{ThoughtRepository, UserWriter},
+        ports::{FeedQuery, ThoughtRepository, UserWriter},
        value_objects::*,
    };

@@ -389,13 +367,10 @@ mod tests {
        let (_, _) = seed(&pool, "alice", "hello").await;
        let repo = PgFeedRepository::new(pool);
        let result = repo
-            .public_feed(
-                &PageParams {
-                    page: 1,
-                    per_page: 20,
-                },
+            .query(&FeedQuery::public(
+                PageParams { page: 1, per_page: 20 },
                None,
-            )
+            ))
            .await
            .unwrap();
        assert_eq!(result.total, 1);
@@ -408,14 +383,11 @@ mod tests {
        let (_, _) = seed(&pool, "bob", "goodbye world").await;
        let repo = PgFeedRepository::new(pool);
        let result = repo
-            .search(
+            .query(&FeedQuery::search(
                "hello world",
-                &PageParams {
-                    page: 1,
-                    per_page: 20,
-                },
+                PageParams { page: 1, per_page: 20 },
                None,
-            )
+            ))
            .await
            .unwrap();
        assert!(result.total >= 1);
--- a/crates/application/Cargo.toml
+++ b/crates/application/Cargo.toml
@@ -4,8 +4,9 @@ version = "0.1.0"
 edition = "2021"

 [dependencies]
-domain      = { workspace = true }
-async-trait = { workspace = true }
+domain           = { workspace = true }
+activitypub-base = { workspace = true }
+async-trait      = { workspace = true }
 thiserror   = { workspace = true }
 uuid        = { workspace = true }
 chrono      = { workspace = true }
--- a/crates/application/src/lib.rs
+++ b/crates/application/src/lib.rs
@@ -1,2 +1,5 @@
 pub mod services;
 pub mod use_cases;
+
+#[cfg(test)]
+pub mod testing;
--- a/crates/application/src/services/federation_event.rs
+++ b/crates/application/src/services/federation_event.rs
@@ -1,8 +1,9 @@
+use activitypub_base::{ActivityPubRepository, OutboundFederationPort};
 use domain::{
    errors::DomainError,
    events::DomainEvent,
    models::thought::Visibility,
-    ports::{ActivityPubRepository, OutboundFederationPort, ThoughtRepository, UserReader},
+    ports::{ThoughtRepository, UserReader},
    value_objects::ThoughtId,
 };
 use std::sync::Arc;
@@ -212,13 +213,14 @@ impl FederationEventService {
 #[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,
-        ports::{ActivityPubRepository, OutboundFederationPort},
        testing::TestStore,
        value_objects::*,
    };
@@ -325,12 +327,23 @@ mod tests {
    }

    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(store.clone()),
+            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),
        }
    }

@@ -452,7 +465,8 @@ mod tests {
        let alice = alice();
        let mut thought = local_thought(alice.id.clone());
        thought.local = false;
-        store.thought_ap_ids.lock().unwrap().insert(
+        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(),
        );
@@ -460,7 +474,7 @@ mod tests {
        store.thoughts.lock().unwrap().push(thought.clone());

        let spy = Arc::new(SpyPort::default());
-        svc(&store, spy.clone())
+        svc_with_ap(&store, ap_repo, spy.clone())
            .process(&DomainEvent::BoostAdded {
                boost_id: BoostId::new(),
                user_id: alice.id.clone(),
@@ -604,14 +618,15 @@ mod tests {
        let alice = alice();
        let mut thought = local_thought(alice.id.clone());
        thought.local = false;
-        store.thought_ap_ids.lock().unwrap().insert(
+        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(&store, spy.clone())
+        svc_with_ap(&store, ap_repo, spy.clone())
            .process(&DomainEvent::BoostRemoved {
                user_id: alice.id.clone(),
                thought_id: thought.id.clone(),
@@ -673,28 +688,28 @@ mod tests {
            PasswordHash("h".into()),
        );
        author.local = false;
-        store.actor_ap_urls.lock().unwrap().insert(
-            author.id.clone(),
-            domain::ports::ActorApUrls {
-                ap_id: "https://mastodon.social/users/author".into(),
-                inbox_url: "https://mastodon.social/users/author/inbox".into(),
-            },
-        );
-
        let thought = local_thought(author.id.clone());
-        store.thought_ap_ids.lock().unwrap().insert(
-            thought.id.clone(),
-            "https://mastodon.social/posts/123".into(),
-        );
-
        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(&store, spy.clone())
+        svc_with_ap(&store, ap_repo, spy.clone())
            .process(&DomainEvent::LikeAdded {
                like_id: LikeId::new(),
                user_id: liker.id,
--- a/crates/application/src/testing.rs
+++ b/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<(), DomainError> {
+        Ok(())
+    }
+    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())
+    }
+}
--- a/crates/application/src/use_cases/auth.rs
+++ b/crates/application/src/use_cases/auth.rs
@@ -38,13 +38,11 @@ pub async fn register(
        .save(&user)
        .await
        .map_err(|e| match e {
-            DomainError::Conflict(ref c) if c.contains("username") => {
-                DomainError::Conflict("username taken".into())
-            }
-            DomainError::Conflict(ref c) if c.contains("email") => {
-                DomainError::Conflict("email taken".into())
-            }
-            DomainError::Conflict(_) => DomainError::Conflict("already exists".into()),
+            DomainError::Conflict(c) => match c.as_str() {
+                "users_username_key" => DomainError::Conflict("username taken".into()),
+                "users_email_key" => DomainError::Conflict("email taken".into()),
+                _ => DomainError::Conflict("already exists".into()),
+            },
            other => other,
        })?;
    events
@@ -111,6 +109,7 @@ mod tests {
    /// Simulates a concurrent registration that slips past the pre-checks and
    /// hits the DB unique constraint — exactly what happens in the TOCTOU window.
    struct ConflictOnSaveStore(TestStore);
+    struct EmailConflictOnSaveStore(TestStore);

    #[async_trait]
    impl UserReader for ConflictOnSaveStore {
@@ -154,6 +153,48 @@ mod tests {
        }
    }

+    #[async_trait]
+    impl UserReader for EmailConflictOnSaveStore {
+        async fn find_by_id(&self, id: &UserId) -> Result<Option<User>, DomainError> {
+            self.0.find_by_id(id).await
+        }
+        async fn find_by_username(
+            &self,
+            username: &Username,
+        ) -> Result<Option<User>, DomainError> {
+            self.0.find_by_username(username).await
+        }
+        async fn find_by_email(&self, email: &Email) -> Result<Option<User>, DomainError> {
+            self.0.find_by_email(email).await
+        }
+        async fn list_with_stats(&self) -> Result<Vec<UserSummary>, DomainError> {
+            self.0.list_with_stats().await
+        }
+        async fn count(&self) -> Result<i64, DomainError> {
+            self.0.count().await
+        }
+    }
+
+    #[async_trait]
+    impl UserWriter for EmailConflictOnSaveStore {
+        async fn save(&self, _user: &User) -> Result<(), DomainError> {
+            Err(DomainError::Conflict("users_email_key".into()))
+        }
+        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> {
+            self.0
+                .update_profile(user_id, display_name, bio, avatar_url, header_url, custom_css)
+                .await
+        }
+    }
+
    struct FakeHasher;
    #[async_trait]
    impl PasswordHasher for FakeHasher {
@@ -315,4 +356,17 @@ mod tests {
            err
        );
    }
+
+    #[tokio::test]
+    async fn register_maps_db_conflict_on_email_to_conflict() {
+        let store = EmailConflictOnSaveStore(TestStore::default());
+        let err = register(&store, &FakeHasher, &FakeAuth, &NoOpEventPublisher, input())
+            .await
+            .unwrap_err();
+        assert!(
+            matches!(err, DomainError::Conflict(ref m) if m == "email taken"),
+            "expected 'email taken', got: {:?}",
+            err
+        );
+    }
 }
--- a/crates/application/src/use_cases/federation_management.rs
+++ b/crates/application/src/use_cases/federation_management.rs
@@ -1,3 +1,4 @@
+use activitypub_base::ActivityPubRepository;
 use domain::{
    errors::DomainError,
    models::{
@@ -6,9 +7,9 @@ use domain::{
        remote_actor::RemoteActor,
    },
    ports::{
-        ActivityPubRepository, EventPublisher, FederationActionPort, FederationFollowPort,
-        FederationFollowRequestPort, FederationSchedulerPort, FeedRepository, FollowRepository,
-        RemoteActorConnectionRepository, UserReader,
+        EventPublisher, FederationActionPort, FederationFollowPort,
+        FederationFollowRequestPort, FederationSchedulerPort, FeedQuery, FeedRepository,
+        FollowRepository, RemoteActorConnectionRepository, UserReader,
    },
    value_objects::UserId,
 };
@@ -85,7 +86,7 @@ pub async fn get_remote_actor_posts(
        Some(id) => id,
        None => ap_repo.intern_remote_actor(&actor.url).await?,
    };
-    let result = feed.user_feed(&author_id, &page, viewer_id).await?;
+    let result = feed.query(&FeedQuery::user(author_id, page.clone(), viewer_id.cloned())).await?;
    if let Some(outbox_url) = actor.outbox_url {
        let _ = scheduler
            .schedule_actor_posts_fetch(&actor.url, &outbox_url)
--- a/crates/application/src/use_cases/feed.rs
+++ b/crates/application/src/use_cases/feed.rs
@@ -4,7 +4,7 @@ use domain::{
        feed::{FeedEntry, PageParams, Paginated, UserSummary},
        user::User,
    },
-    ports::{FeedRepository, FollowRepository, TagRepository, UserReader},
+    ports::{FeedQuery, FeedRepository, FollowRepository, TagRepository, UserReader},
    value_objects::UserId,
 };

@@ -16,7 +16,7 @@ pub async fn get_home_feed(
 ) -> Result<Paginated<FeedEntry>, DomainError> {
    let mut following_ids = follows.get_accepted_following_ids(user_id).await?;
    following_ids.push(user_id.clone()); // include own thoughts in home feed
-    feed.home_feed(&following_ids, &page, Some(user_id)).await
+    feed.query(&FeedQuery::home(user_id.clone(), following_ids, page)).await
 }

 pub async fn get_public_feed(
@@ -24,7 +24,7 @@ pub async fn get_public_feed(
    viewer_id: Option<&UserId>,
    page: PageParams,
 ) -> Result<Paginated<FeedEntry>, DomainError> {
-    feed.public_feed(&page, viewer_id).await
+    feed.query(&FeedQuery::public(page, viewer_id.cloned())).await
 }

 pub async fn get_user_feed(
@@ -33,7 +33,7 @@ pub async fn get_user_feed(
    page: PageParams,
    viewer_id: Option<&UserId>,
 ) -> Result<Paginated<FeedEntry>, DomainError> {
-    feed.user_feed(user_id, &page, viewer_id).await
+    feed.query(&FeedQuery::user(user_id.clone(), page, viewer_id.cloned())).await
 }

 pub async fn get_followers(
@@ -58,7 +58,7 @@ pub async fn get_by_tag(
    page: PageParams,
    viewer_id: Option<&UserId>,
 ) -> Result<Paginated<FeedEntry>, DomainError> {
-    feed.tag_feed(tag_name, &page, viewer_id).await
+    feed.query(&FeedQuery::tag(tag_name, page, viewer_id.cloned())).await
 }

 pub async fn search(
@@ -67,7 +67,7 @@ pub async fn search(
    page: PageParams,
    viewer_id: Option<&UserId>,
 ) -> Result<Paginated<FeedEntry>, DomainError> {
-    feed.search(query, &page, viewer_id).await
+    feed.query(&FeedQuery::search(query, page, viewer_id.cloned())).await
 }

 pub async fn list_users(users: &dyn UserReader) -> Result<Vec<UserSummary>, DomainError> {
--- a/crates/application/src/use_cases/thoughts.rs
+++ b/crates/application/src/use_cases/thoughts.rs
@@ -6,30 +6,6 @@ use domain::{
    value_objects::{Content, ThoughtId, UserId},
 };

-fn extract_hashtags(content: &str) -> Vec<String> {
-    let mut tags = Vec::new();
-    let mut chars = content.char_indices().peekable();
-    while let Some((_, c)) = chars.next() {
-        if c == '#'
-            && chars
-                .peek()
-                .map(|(_, nc)| nc.is_alphanumeric())
-                .unwrap_or(false)
-        {
-            let tag: String = chars
-                .by_ref()
-                .take_while(|(_, nc)| nc.is_alphanumeric() || *nc == '_')
-                .map(|(_, nc)| nc)
-                .collect();
-            if !tag.is_empty() {
-                tags.push(tag.to_lowercase());
-            }
-        }
-    }
-    tags.dedup();
-    tags
-}
-
 fn require_owner(thought: &Thought, user_id: &UserId) -> Result<(), DomainError> {
    if thought.user_id != *user_id {
        return Err(DomainError::NotFound);
@@ -76,8 +52,8 @@ pub async fn create_thought(
    thoughts.save(&thought).await?;

    // Extract and attach hashtags from content.
-    for tag_name in extract_hashtags(content.as_str()) {
-        if let Ok(tag) = tags.find_or_create(&tag_name).await {
+    for h in domain::hashtag::extract(content.as_str()) {
+        if let Ok(tag) = tags.find_or_create(&h.normalized).await {
            let _ = tags.attach_to_thought(&thought.id, tag.id).await;
        }
    }
@@ -195,6 +171,33 @@ mod tests {
        assert!(matches!(staged[0], DomainEvent::ThoughtCreated { .. }));
    }

+    #[tokio::test]
+    async fn delete_thought_stages_outbox_event() {
+        let store = TestStore::default();
+        let outbox = TestOutbox::default();
+        let u = user();
+        store.users.lock().unwrap().push(u.clone());
+        let out = create_thought(
+            &store,
+            &store,
+            &store,
+            &NoOpEventPublisher,
+            &NoOpOutboxWriter,
+            input(u.id.clone()),
+        )
+        .await
+        .unwrap();
+        let tid = out.thought.id.clone();
+
+        delete_thought(&store, &NoOpEventPublisher, &outbox, &tid, &u.id)
+            .await
+            .unwrap();
+
+        let staged = outbox.staged();
+        assert_eq!(staged.len(), 1);
+        assert!(matches!(&staged[0], DomainEvent::ThoughtDeleted { thought_id, .. } if *thought_id == tid));
+    }
+
    #[tokio::test]
    async fn delete_own_thought_succeeds() {
        let store = TestStore::default();
--- a/crates/domain/src/hashtag.rs
+++ b/crates/domain/src/hashtag.rs
@@ -0,0 +1,139 @@
+use std::collections::HashSet;
+
+/// A hashtag extracted from content.
+#[derive(Debug, Clone, PartialEq, Eq, Hash)]
+pub struct Hashtag {
+    /// Original casing, e.g. "Rust"
+    pub raw: String,
+    /// Lowercased, e.g. "rust" — used for DB lookups
+    pub normalized: String,
+    /// "tags/rust" — callers prepend base_url
+    pub url_slug: String,
+    /// "#rust" — used directly in AP tag array
+    pub ap_name: String,
+}
+
+/// Extract hashtags from content using a char-by-char scan.
+///
+/// Rules:
+/// - Tag starts after a bare `#` followed immediately by an alphanumeric char.
+/// - Tag chars: `[A-Za-z0-9_]`.
+/// - Deduplicated case-insensitively; first occurrence wins.
+/// - Returned in order of first appearance.
+pub fn extract(content: &str) -> Vec<Hashtag> {
+    let mut seen: HashSet<String> = HashSet::new();
+    let mut tags: Vec<Hashtag> = Vec::new();
+    let mut chars = content.char_indices().peekable();
+
+    while let Some((_, c)) = chars.next() {
+        if c == '#'
+            && chars
+                .peek()
+                .map(|(_, nc)| nc.is_alphanumeric())
+                .unwrap_or(false)
+        {
+            let raw: String = chars
+                .by_ref()
+                .take_while(|(_, nc)| nc.is_alphanumeric() || *nc == '_')
+                .map(|(_, nc)| nc)
+                .collect();
+
+            if raw.is_empty() {
+                continue;
+            }
+
+            let normalized = raw.to_lowercase();
+            if seen.insert(normalized.clone()) {
+                tags.push(Hashtag {
+                    url_slug: format!("tags/{}", normalized),
+                    ap_name: format!("#{}", normalized),
+                    raw,
+                    normalized,
+                });
+            }
+        }
+    }
+
+    tags
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    fn names(tags: &[Hashtag]) -> Vec<&str> {
+        tags.iter().map(|h| h.normalized.as_str()).collect()
+    }
+
+    #[test]
+    fn basic() {
+        let tags = extract("Hello #world and #Rust!");
+        assert_eq!(names(&tags), ["world", "rust"]);
+    }
+
+    #[test]
+    fn fields() {
+        let tags = extract("#Rust");
+        assert_eq!(tags.len(), 1);
+        let h = &tags[0];
+        assert_eq!(h.raw, "Rust");
+        assert_eq!(h.normalized, "rust");
+        assert_eq!(h.url_slug, "tags/rust");
+        assert_eq!(h.ap_name, "#rust");
+    }
+
+    #[test]
+    fn dedup_case_insensitive() {
+        let tags = extract("#rust #Rust #RUST");
+        assert_eq!(names(&tags), ["rust"]);
+        assert_eq!(tags[0].raw, "rust"); // first occurrence wins
+    }
+
+    #[test]
+    fn deduplicates_non_adjacent() {
+        // The old algorithm used Vec::dedup() which only removes adjacent duplicates.
+        // Using HashSet silently fixed this bug. This test documents the fix.
+        let tags = extract("#a #b #a");
+        assert_eq!(tags.len(), 2);
+        assert_eq!(tags[0].normalized, "a");
+        assert_eq!(tags[1].normalized, "b");
+    }
+
+    #[test]
+    fn mid_word_extracted() {
+        // `text#tag` — `#` not preceded by whitespace is still matched by the
+        // char-by-char scan (the old algorithm didn't require whitespace before `#`).
+        // This test documents the authoritative behaviour: mid-word tags ARE extracted.
+        let tags = extract("text#tag");
+        assert_eq!(names(&tags), ["tag"]);
+    }
+
+    #[test]
+    fn hash_only_ignored() {
+        assert!(extract("# lone hash").is_empty());
+    }
+
+    #[test]
+    fn trailing_punctuation_excluded() {
+        // punctuation after tag terminates the tag, not included
+        let tags = extract("#rust.");
+        assert_eq!(names(&tags), ["rust"]);
+    }
+
+    #[test]
+    fn underscore_allowed() {
+        let tags = extract("#hello_world");
+        assert_eq!(names(&tags), ["hello_world"]);
+    }
+
+    #[test]
+    fn empty_content() {
+        assert!(extract("").is_empty());
+    }
+
+    #[test]
+    fn order_of_appearance() {
+        let tags = extract("#b #a #c");
+        assert_eq!(names(&tags), ["b", "a", "c"]);
+    }
+}
--- a/crates/domain/src/lib.rs
+++ b/crates/domain/src/lib.rs
@@ -1,5 +1,6 @@
 pub mod errors;
 pub mod events;
+pub mod hashtag;
 pub mod models;
 pub mod ports;
 pub mod value_objects;
--- a/crates/domain/src/ports.rs
+++ b/crates/domain/src/ports.rs
@@ -317,37 +317,43 @@ impl<
 {
 }

+#[derive(Debug, Clone)]
+pub enum FeedScope {
+    Home { following_ids: Vec<UserId> },
+    Public,
+    Tag { tag_name: String },
+    User { user_id: UserId },
+    Search { query: String },
+}
+
+#[derive(Debug, Clone)]
+pub struct FeedQuery {
+    pub scope: FeedScope,
+    pub page: PageParams,
+    pub viewer_id: Option<UserId>,
+}
+
+impl FeedQuery {
+    pub fn home(viewer_id: UserId, following_ids: Vec<UserId>, page: PageParams) -> Self {
+        Self { scope: FeedScope::Home { following_ids }, page, viewer_id: Some(viewer_id) }
+    }
+    pub fn public(page: PageParams, viewer_id: Option<UserId>) -> Self {
+        Self { scope: FeedScope::Public, page, viewer_id }
+    }
+    pub fn tag(tag_name: impl Into<String>, page: PageParams, viewer_id: Option<UserId>) -> Self {
+        Self { scope: FeedScope::Tag { tag_name: tag_name.into() }, page, viewer_id }
+    }
+    pub fn user(user_id: UserId, page: PageParams, viewer_id: Option<UserId>) -> Self {
+        Self { scope: FeedScope::User { user_id }, page, viewer_id }
+    }
+    pub fn search(query: impl Into<String>, page: PageParams, viewer_id: Option<UserId>) -> Self {
+        Self { scope: FeedScope::Search { query: query.into() }, page, viewer_id }
+    }
+}
+
 #[async_trait]
 pub trait FeedRepository: Send + Sync {
-    async fn home_feed(
-        &self,
-        following_ids: &[UserId],
-        page: &PageParams,
-        viewer_id: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError>;
-    async fn public_feed(
-        &self,
-        page: &PageParams,
-        viewer_id: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError>;
-    async fn search(
-        &self,
-        query: &str,
-        page: &PageParams,
-        viewer_id: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError>;
-    async fn tag_feed(
-        &self,
-        tag_name: &str,
-        page: &PageParams,
-        viewer_id: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError>;
-    async fn user_feed(
-        &self,
-        user_id: &UserId,
-        page: &PageParams,
-        viewer_id: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError>;
+    async fn query(&self, q: &FeedQuery) -> Result<Paginated<FeedEntry>, DomainError>;
 }

 #[async_trait]
@@ -368,166 +374,6 @@ pub trait SearchPort: Send + Sync {
    ) -> Result<Paginated<User>, DomainError>;
 }

-/// 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: crate::models::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<(), 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>;
-}

 #[async_trait]
 pub trait FederationSchedulerPort: Send + Sync {
--- a/crates/domain/src/testing.rs
+++ b/crates/domain/src/testing.rs
@@ -39,8 +39,6 @@ pub struct TestStore {
    pub actor_ap_ids: Arc<Mutex<HashMap<String, UserId>>>,
    /// ThoughtId → AP object URL (used by get_thought_ap_id)
    pub thought_ap_ids: Arc<Mutex<HashMap<ThoughtId, String>>>,
-    /// UserId → ActorApUrls (used by get_actor_ap_urls)
-    pub actor_ap_urls: Arc<Mutex<HashMap<UserId, ActorApUrls>>>,
 }

 #[async_trait]
@@ -706,63 +704,7 @@ impl RemoteActorConnectionRepository for TestStore {

 #[async_trait]
 impl FeedRepository for TestStore {
-    async fn home_feed(
-        &self,
-        _ids: &[UserId],
-        _p: &PageParams,
-        _v: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError> {
-        Ok(Paginated {
-            items: vec![],
-            total: 0,
-            page: 1,
-            per_page: 20,
-        })
-    }
-    async fn public_feed(
-        &self,
-        _p: &PageParams,
-        _v: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError> {
-        Ok(Paginated {
-            items: vec![],
-            total: 0,
-            page: 1,
-            per_page: 20,
-        })
-    }
-    async fn search(
-        &self,
-        _q: &str,
-        _p: &PageParams,
-        _v: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError> {
-        Ok(Paginated {
-            items: vec![],
-            total: 0,
-            page: 1,
-            per_page: 20,
-        })
-    }
-    async fn tag_feed(
-        &self,
-        _tag_name: &str,
-        _page: &PageParams,
-        _viewer_id: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError> {
-        Ok(Paginated {
-            items: vec![],
-            total: 0,
-            page: 1,
-            per_page: 20,
-        })
-    }
-    async fn user_feed(
-        &self,
-        _user_id: &UserId,
-        _page: &PageParams,
-        _viewer_id: Option<&UserId>,
-    ) -> Result<Paginated<FeedEntry>, DomainError> {
+    async fn query(&self, _q: &crate::ports::FeedQuery) -> Result<Paginated<FeedEntry>, DomainError> {
        Ok(Paginated {
            items: vec![],
            total: 0,
@@ -801,109 +743,6 @@ impl SearchPort for TestStore {
    }
 }

-#[async_trait]
-impl ActivityPubRepository for TestStore {
-    async fn outbox_entries_for_actor(
-        &self,
-        _uid: &UserId,
-    ) -> Result<Vec<crate::ports::OutboxEntry>, DomainError> {
-        Ok(vec![])
-    }
-    async fn outbox_page_for_actor(
-        &self,
-        _uid: &UserId,
-        _before: Option<chrono::DateTime<chrono::Utc>>,
-        _limit: usize,
-    ) -> Result<Vec<crate::ports::OutboxEntry>, DomainError> {
-        Ok(vec![])
-    }
-    async fn find_remote_actor_id(
-        &self,
-        actor_ap_url: &str,
-    ) -> Result<Option<UserId>, DomainError> {
-        Ok(self.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 = crate::models::user::User {
-            id: uid.clone(),
-            username: Username::from_trusted(handle.clone()),
-            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.users.lock().unwrap().push(user);
-        self.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<(), DomainError> {
-        Ok(())
-    }
-    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
-            .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.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())
-    }
-}

 #[async_trait]
 impl FederationSchedulerPort for TestStore {
@@ -964,31 +803,6 @@ impl OutboxWriter for NoOpOutboxWriter {
    }
 }

-#[cfg(test)]
-mod ap_repo_tests {
-    use super::*;
-    use crate::value_objects::UserId;
-
-    #[tokio::test]
-    async fn test_store_outbox_returns_empty() {
-        let store = TestStore::default();
-        let result = store
-            .outbox_entries_for_actor(&UserId::new())
-            .await
-            .unwrap();
-        assert!(result.is_empty());
-    }
-
-    #[tokio::test]
-    async fn test_store_intern_creates_placeholder() {
-        let store = TestStore::default();
-        let url = "https://example.com/users/alice";
-        let id1 = store.intern_remote_actor(url).await.unwrap();
-        let id2 = store.intern_remote_actor(url).await.unwrap();
-        assert_eq!(id1, id2, "intern must be idempotent");
-    }
-}
-
 #[cfg(test)]
 mod federation_port_tests {
    use super::*;
--- a/crates/presentation/Cargo.toml
+++ b/crates/presentation/Cargo.toml
@@ -4,8 +4,9 @@ version = "0.1.0"
 edition = "2021"

 [dependencies]
-domain      = { workspace = true }
-application = { workspace = true }
+domain           = { workspace = true }
+activitypub-base = { workspace = true }
+application      = { workspace = true }
 api-types   = { workspace = true }
 axum        = { workspace = true }
 tower-http  = { workspace = true }
--- a/crates/presentation/src/extractors.rs
+++ b/crates/presentation/src/extractors.rs
@@ -2,6 +2,27 @@ use crate::{errors::ApiError, state::AppState};
 use axum::{extract::FromRequestParts, http::request::Parts};
 use domain::value_objects::UserId;

+// ---------------------------------------------------------------------------
+// Deps<S> extractor — narrows AppState to a handler-specific deps struct
+// ---------------------------------------------------------------------------
+
+pub struct Deps<S>(pub S);
+
+pub trait FromAppState: Sized {
+    fn from_state(s: &AppState) -> Self;
+}
+
+impl<S: FromAppState + Send + 'static> FromRequestParts<AppState> for Deps<S> {
+    type Rejection = std::convert::Infallible;
+
+    async fn from_request_parts(
+        _parts: &mut Parts,
+        state: &AppState,
+    ) -> Result<Self, Self::Rejection> {
+        Ok(Deps(S::from_state(state)))
+    }
+}
+
 pub struct AuthUser(pub UserId);
 pub struct OptionalAuthUser(pub Option<UserId>);

--- a/crates/presentation/src/handlers/api_keys.rs
+++ b/crates/presentation/src/handlers/api_keys.rs
@@ -1,23 +1,40 @@
-use crate::{errors::ApiError, extractors::AuthUser, state::AppState};
+use crate::{
+    errors::ApiError,
+    extractors::{AuthUser, Deps, FromAppState},
+    state::AppState,
+};
 use api_types::{
    requests::CreateApiKeyRequest,
    responses::{ApiKeyResponse, CreatedApiKeyResponse},
 };
 use application::use_cases::api_keys::{create_api_key, delete_api_key, list_api_keys};
 use axum::{
-    extract::{Path, State},
+    extract::Path,
    http::StatusCode,
    Json,
 };
-use domain::value_objects::ApiKeyId;
+use domain::{ports::ApiKeyRepository, value_objects::ApiKeyId};
+use std::sync::Arc;
 use uuid::Uuid;

+pub struct ApiKeysDeps {
+    pub api_keys: Arc<dyn ApiKeyRepository>,
+}
+
+impl FromAppState for ApiKeysDeps {
+    fn from_state(s: &AppState) -> Self {
+        Self {
+            api_keys: s.api_keys.clone(),
+        }
+    }
+}
+
 #[utoipa::path(get, path = "/api-keys", responses((status = 200, description = "API keys", body = Vec<ApiKeyResponse>)), security(("bearer_auth" = [])))]
 pub async fn get_api_keys(
-    State(s): State<AppState>,
+    Deps(d): Deps<ApiKeysDeps>,
    AuthUser(uid): AuthUser,
 ) -> Result<Json<Vec<ApiKeyResponse>>, ApiError> {
-    let keys = list_api_keys(&*s.api_keys, &uid).await?;
+    let keys = list_api_keys(&*d.api_keys, &uid).await?;
    Ok(Json(
        keys.into_iter()
            .map(|k| ApiKeyResponse {
@@ -30,21 +47,21 @@ pub async fn get_api_keys(
 }
 #[utoipa::path(post, path = "/api-keys", request_body = CreateApiKeyRequest, responses((status = 200, description = "Created — raw key shown once", body = CreatedApiKeyResponse)), security(("bearer_auth" = [])))]
 pub async fn post_api_key(
-    State(s): State<AppState>,
+    Deps(d): Deps<ApiKeysDeps>,
    AuthUser(uid): AuthUser,
    Json(body): Json<CreateApiKeyRequest>,
 ) -> Result<Json<serde_json::Value>, ApiError> {
-    let (key, raw) = create_api_key(&*s.api_keys, &uid, body.name).await?;
+    let (key, raw) = create_api_key(&*d.api_keys, &uid, body.name).await?;
    Ok(Json(
        serde_json::json!({ "id": key.id.as_uuid(), "name": key.name, "key": raw }),
    ))
 }
 #[utoipa::path(delete, path = "/api-keys/{id}", params(("id" = uuid::Uuid, Path, description = "Key ID")), responses((status = 204, description = "Deleted")), security(("bearer_auth" = [])))]
 pub async fn delete_api_key_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<ApiKeysDeps>,
    AuthUser(uid): AuthUser,
    Path(id): Path<Uuid>,
 ) -> Result<StatusCode, ApiError> {
-    delete_api_key(&*s.api_keys, &uid, &ApiKeyId::from_uuid(id)).await?;
+    delete_api_key(&*d.api_keys, &uid, &ApiKeyId::from_uuid(id)).await?;
    Ok(StatusCode::NO_CONTENT)
 }
--- a/crates/presentation/src/handlers/auth.rs
+++ b/crates/presentation/src/handlers/auth.rs
@@ -1,10 +1,34 @@
-use crate::{errors::ApiError, state::AppState};
+use crate::{
+    errors::ApiError,
+    extractors::{Deps, FromAppState},
+    state::AppState,
+};
 use api_types::{
    requests::{LoginRequest, RegisterRequest},
    responses::{AuthResponse, ErrorResponse, UserResponse},
 };
 use application::use_cases::auth::{login, register, LoginInput, RegisterInput};
-use axum::{extract::State, http::StatusCode, response::IntoResponse, Json};
+use axum::{http::StatusCode, response::IntoResponse, Json};
+use domain::ports::{AuthService, EventPublisher, PasswordHasher, UserRepository};
+use std::sync::Arc;
+
+pub struct AuthDeps {
+    pub users: Arc<dyn UserRepository>,
+    pub hasher: Arc<dyn PasswordHasher>,
+    pub auth: Arc<dyn AuthService>,
+    pub events: Arc<dyn EventPublisher>,
+}
+
+impl FromAppState for AuthDeps {
+    fn from_state(s: &AppState) -> Self {
+        Self {
+            users: s.users.clone(),
+            hasher: s.hasher.clone(),
+            auth: s.auth.clone(),
+            events: s.events.clone(),
+        }
+    }
+}

 pub fn to_user_response(u: &domain::models::user::User) -> UserResponse {
    UserResponse {
@@ -31,14 +55,14 @@ pub fn to_user_response(u: &domain::models::user::User) -> UserResponse {
    )
 )]
 pub async fn post_register(
-    State(s): State<AppState>,
+    Deps(d): Deps<AuthDeps>,
    Json(body): Json<RegisterRequest>,
 ) -> Result<impl IntoResponse, ApiError> {
    let out = register(
-        &*s.users,
-        &*s.hasher,
-        &*s.auth,
-        &*s.events,
+        &*d.users,
+        &*d.hasher,
+        &*d.auth,
+        &*d.events,
        RegisterInput {
            username: body.username,
            email: body.email,
@@ -62,13 +86,13 @@ pub async fn post_register(
    )
 )]
 pub async fn post_login(
-    State(s): State<AppState>,
+    Deps(d): Deps<AuthDeps>,
    Json(body): Json<LoginRequest>,
 ) -> Result<impl IntoResponse, ApiError> {
    let out = login(
-        &*s.users,
-        &*s.hasher,
-        &*s.auth,
+        &*d.users,
+        &*d.hasher,
+        &*d.auth,
        LoginInput {
            email: body.email,
            password: body.password,
--- a/crates/presentation/src/handlers/federation_actors.rs
+++ b/crates/presentation/src/handlers/federation_actors.rs
@@ -1,5 +1,7 @@
 use crate::{
-    errors::ApiError, extractors::OptionalAuthUser, handlers::feed::to_thought_response,
+    errors::ApiError,
+    extractors::{Deps, FromAppState, OptionalAuthUser},
+    handlers::feed::to_thought_response,
    state::AppState,
 };
 use api_types::{
@@ -10,13 +12,41 @@ use application::use_cases::federation_management::{
    get_actor_connections_page, get_remote_actor_posts,
 };
 use axum::{
-    extract::{Path, Query, State},
+    extract::{Path, Query},
    Json,
 };
-use domain::models::feed::PageParams;
+use activitypub_base::ActivityPubRepository;
+use domain::{
+    models::feed::PageParams,
+    ports::{
+        FederationActionPort, FederationSchedulerPort, FeedRepository,
+        RemoteActorConnectionRepository,
+    },
+};
+use std::sync::Arc;
+
+pub struct FederationActorsDeps {
+    pub federation: Arc<dyn FederationActionPort>,
+    pub ap_repo: Arc<dyn ActivityPubRepository>,
+    pub feed: Arc<dyn FeedRepository>,
+    pub federation_scheduler: Arc<dyn FederationSchedulerPort>,
+    pub remote_actor_connections: Arc<dyn RemoteActorConnectionRepository>,
+}
+
+impl FromAppState for FederationActorsDeps {
+    fn from_state(s: &AppState) -> Self {
+        Self {
+            federation: s.federation.clone(),
+            ap_repo: s.ap_repo.clone(),
+            feed: s.feed.clone(),
+            federation_scheduler: s.federation_scheduler.clone(),
+            remote_actor_connections: s.remote_actor_connections.clone(),
+        }
+    }
+}

 pub async fn remote_actor_posts_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<FederationActorsDeps>,
    Path(handle): Path<String>,
    Query(q): Query<PaginationQuery>,
    OptionalAuthUser(viewer): OptionalAuthUser,
@@ -26,10 +56,10 @@ pub async fn remote_actor_posts_handler(
        per_page: q.per_page(),
    };
    let result = get_remote_actor_posts(
-        &*s.federation,
-        &*s.ap_repo,
-        &*s.feed,
-        &*s.federation_scheduler,
+        &*d.federation,
+        &*d.ap_repo,
+        &*d.feed,
+        &*d.federation_scheduler,
        &handle,
        page,
        viewer.as_ref(),
@@ -44,31 +74,31 @@ pub async fn remote_actor_posts_handler(
 }

 pub async fn actor_followers_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<FederationActorsDeps>,
    Path(handle): Path<String>,
    Query(q): Query<PaginationQuery>,
 ) -> Result<Json<ActorConnectionPageResponse>, ApiError> {
-    actor_connections_handler(s, handle, "followers", q.page() as u32).await
+    actor_connections_handler(d, handle, "followers", q.page() as u32).await
 }

 pub async fn actor_following_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<FederationActorsDeps>,
    Path(handle): Path<String>,
    Query(q): Query<PaginationQuery>,
 ) -> Result<Json<ActorConnectionPageResponse>, ApiError> {
-    actor_connections_handler(s, handle, "following", q.page() as u32).await
+    actor_connections_handler(d, handle, "following", q.page() as u32).await
 }

 async fn actor_connections_handler(
-    s: AppState,
+    d: FederationActorsDeps,
    handle: String,
    connection_type: &str,
    page: u32,
 ) -> Result<Json<ActorConnectionPageResponse>, ApiError> {
    let (items, has_more) = get_actor_connections_page(
-        &*s.federation,
-        &*s.remote_actor_connections,
-        &*s.federation_scheduler,
+        &*d.federation,
+        &*d.remote_actor_connections,
+        &*d.federation_scheduler,
        &handle,
        connection_type,
        page,
--- a/crates/presentation/src/handlers/federation_management.rs
+++ b/crates/presentation/src/handlers/federation_management.rs
@@ -1,11 +1,17 @@
-use crate::{errors::ApiError, extractors::AuthUser, state::AppState};
+use crate::{
+    errors::ApiError,
+    extractors::{AuthUser, Deps, FromAppState},
+    state::AppState,
+};
 use api_types::responses::{ProfileField, RemoteActorResponse};
 use application::use_cases::federation_management::{
    accept_follow_request, list_pending_requests, list_remote_followers, list_remote_following,
    reject_follow_request, remove_remote_following,
 };
-use axum::{extract::State, http::StatusCode, Json};
+use axum::{http::StatusCode, Json};
+use domain::ports::{EventPublisher, FederationActionPort, FollowRepository, UserRepository};
 use serde::Deserialize;
+use std::sync::Arc;

 #[derive(Deserialize)]
 pub struct ActorUrlBody {
@@ -17,6 +23,24 @@ pub struct HandleBody {
    pub handle: String,
 }

+pub struct FederationManagementDeps {
+    pub federation: Arc<dyn FederationActionPort>,
+    pub follows: Arc<dyn FollowRepository>,
+    pub users: Arc<dyn UserRepository>,
+    pub events: Arc<dyn EventPublisher>,
+}
+
+impl FromAppState for FederationManagementDeps {
+    fn from_state(s: &AppState) -> Self {
+        Self {
+            federation: s.federation.clone(),
+            follows: s.follows.clone(),
+            users: s.users.clone(),
+            events: s.events.clone(),
+        }
+    }
+}
+
 fn to_response(a: domain::models::remote_actor::RemoteActor) -> RemoteActorResponse {
    RemoteActorResponse {
        handle: a.handle,
@@ -38,57 +62,57 @@ fn to_response(a: domain::models::remote_actor::RemoteActor) -> RemoteActorRespo
 }

 pub async fn get_pending_requests(
-    State(s): State<AppState>,
+    Deps(d): Deps<FederationManagementDeps>,
    AuthUser(uid): AuthUser,
 ) -> Result<Json<Vec<RemoteActorResponse>>, ApiError> {
-    let actors = list_pending_requests(&*s.federation, &uid).await?;
+    let actors = list_pending_requests(&*d.federation, &uid).await?;
    Ok(Json(actors.into_iter().map(to_response).collect()))
 }

 pub async fn post_accept_request(
-    State(s): State<AppState>,
+    Deps(d): Deps<FederationManagementDeps>,
    AuthUser(uid): AuthUser,
    Json(body): Json<ActorUrlBody>,
 ) -> Result<StatusCode, ApiError> {
-    accept_follow_request(&*s.federation, &uid, &body.actor_url).await?;
+    accept_follow_request(&*d.federation, &uid, &body.actor_url).await?;
    Ok(StatusCode::NO_CONTENT)
 }

 pub async fn delete_follower(
-    State(s): State<AppState>,
+    Deps(d): Deps<FederationManagementDeps>,
    AuthUser(uid): AuthUser,
    Json(body): Json<ActorUrlBody>,
 ) -> Result<StatusCode, ApiError> {
-    reject_follow_request(&*s.federation, &uid, &body.actor_url).await?;
+    reject_follow_request(&*d.federation, &uid, &body.actor_url).await?;
    Ok(StatusCode::NO_CONTENT)
 }

 pub async fn get_remote_followers(
-    State(s): State<AppState>,
+    Deps(d): Deps<FederationManagementDeps>,
    AuthUser(uid): AuthUser,
 ) -> Result<Json<Vec<RemoteActorResponse>>, ApiError> {
-    let actors = list_remote_followers(&*s.federation, &uid).await?;
+    let actors = list_remote_followers(&*d.federation, &uid).await?;
    Ok(Json(actors.into_iter().map(to_response).collect()))
 }

 pub async fn get_remote_following(
-    State(s): State<AppState>,
+    Deps(d): Deps<FederationManagementDeps>,
    AuthUser(uid): AuthUser,
 ) -> Result<Json<Vec<RemoteActorResponse>>, ApiError> {
-    let actors = list_remote_following(&*s.federation, &uid).await?;
+    let actors = list_remote_following(&*d.federation, &uid).await?;
    Ok(Json(actors.into_iter().map(to_response).collect()))
 }

 pub async fn delete_following(
-    State(s): State<AppState>,
+    Deps(d): Deps<FederationManagementDeps>,
    AuthUser(uid): AuthUser,
    Json(body): Json<HandleBody>,
 ) -> Result<StatusCode, ApiError> {
    remove_remote_following(
-        &*s.follows,
-        &*s.users,
-        &*s.federation,
-        &*s.events,
+        &*d.follows,
+        &*d.users,
+        &*d.federation,
+        &*d.events,
        &uid,
        &body.handle,
    )
--- a/crates/presentation/src/handlers/feed.rs
+++ b/crates/presentation/src/handlers/feed.rs
@@ -1,6 +1,6 @@
 use crate::{
    errors::ApiError,
-    extractors::{AuthUser, OptionalAuthUser},
+    extractors::{Deps, FromAppState, OptionalAuthUser, AuthUser},
    handlers::auth::to_user_response,
    state::AppState,
 };
@@ -12,12 +12,38 @@ use application::use_cases::feed::{
 };
 use application::use_cases::profile::{get_user_by_id_or_username, get_user_by_username};
 use axum::{
-    extract::{Path, Query, State},
+    extract::{Path, Query},
    http::{header, HeaderMap},
    response::{IntoResponse, Response},
    Json,
 };
-use domain::models::feed::PageParams;
+use domain::{
+    models::feed::PageParams,
+    ports::{FederationActionPort, FeedRepository, FollowRepository, SearchPort, TagRepository, UserRepository},
+};
+use std::sync::Arc;
+
+pub struct FeedDeps {
+    pub feed: Arc<dyn FeedRepository>,
+    pub follows: Arc<dyn FollowRepository>,
+    pub search: Arc<dyn SearchPort>,
+    pub federation: Arc<dyn FederationActionPort>,
+    pub users: Arc<dyn UserRepository>,
+    pub tags: Arc<dyn TagRepository>,
+}
+
+impl FromAppState for FeedDeps {
+    fn from_state(s: &AppState) -> Self {
+        Self {
+            feed: s.feed.clone(),
+            follows: s.follows.clone(),
+            search: s.search.clone(),
+            federation: s.federation.clone(),
+            users: s.users.clone(),
+            tags: s.tags.clone(),
+        }
+    }
+}

 pub fn to_thought_response(e: &domain::models::feed::FeedEntry) -> ThoughtResponse {
    ThoughtResponse {
@@ -46,7 +72,7 @@ pub fn to_thought_response(e: &domain::models::feed::FeedEntry) -> ThoughtRespon
    security(("bearer_auth" = []))
 )]
 pub async fn home_feed(
-    State(s): State<AppState>,
+    Deps(d): Deps<FeedDeps>,
    AuthUser(uid): AuthUser,
    Query(q): Query<PaginationQuery>,
 ) -> Result<Json<serde_json::Value>, ApiError> {
@@ -54,7 +80,7 @@ pub async fn home_feed(
        page: q.page(),
        per_page: q.per_page(),
    };
-    let result = get_home_feed(&*s.feed, &*s.follows, &uid, page).await?;
+    let result = get_home_feed(&*d.feed, &*d.follows, &uid, page).await?;
    Ok(Json(serde_json::json!({
        "items": result.items.iter().map(to_thought_response).collect::<Vec<_>>(),
        "total": result.total,
@@ -69,7 +95,7 @@ pub async fn home_feed(
    responses((status = 200, description = "Public feed"))
 )]
 pub async fn public_feed(
-    State(s): State<AppState>,
+    Deps(d): Deps<FeedDeps>,
    OptionalAuthUser(viewer): OptionalAuthUser,
    Query(q): Query<PaginationQuery>,
 ) -> Result<Json<serde_json::Value>, ApiError> {
@@ -77,7 +103,7 @@ pub async fn public_feed(
        page: q.page(),
        per_page: q.per_page(),
    };
-    let result = get_public_feed(&*s.feed, viewer.as_ref(), page).await?;
+    let result = get_public_feed(&*d.feed, viewer.as_ref(), page).await?;
    Ok(Json(serde_json::json!({
        "items": result.items.iter().map(to_thought_response).collect::<Vec<_>>(),
        "total": result.total,
@@ -92,7 +118,7 @@ pub async fn public_feed(
    responses((status = 200, description = "Search results: thoughts and users"))
 )]
 pub async fn search_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<FeedDeps>,
    OptionalAuthUser(viewer): OptionalAuthUser,
    Query(q): Query<SearchQuery>,
 ) -> Result<Json<serde_json::Value>, ApiError> {
@@ -103,8 +129,8 @@ pub async fn search_handler(
    let query = q.q.trim().to_string();

    let (thoughts_result, users_result) = tokio::join!(
-        s.search.search_thoughts(&query, &page, viewer.as_ref()),
-        s.search.search_users(&query, &page),
+        d.search.search_thoughts(&query, &page, viewer.as_ref()),
+        d.search.search_users(&query, &page),
    );

    let thoughts = thoughts_result?
@@ -127,7 +153,7 @@ pub async fn search_handler(
 }

 pub async fn get_following_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<FeedDeps>,
    Path(param): Path<String>,
    Query(q): Query<PaginationQuery>,
    headers: HeaderMap,
@@ -138,22 +164,22 @@ pub async fn get_following_handler(
        .unwrap_or("");

    if accept.contains("application/activity+json") {
-        let user = get_user_by_id_or_username(&*s.users, &param).await?;
+        let user = get_user_by_id_or_username(&*d.users, &param).await?;
        let user_id = user.id;
        let page = q.page().try_into().ok();
-        let json = s
+        let json = d
            .federation
            .following_collection_json(&user_id, page)
            .await?;
        return Ok(([(header::CONTENT_TYPE, "application/activity+json")], json).into_response());
    }

-    let user = get_user_by_username(&*s.users, &param).await?;
+    let user = get_user_by_username(&*d.users, &param).await?;
    let page = PageParams {
        page: q.page(),
        per_page: q.per_page(),
    };
-    let result = get_following(&*s.follows, &user.id, page).await?;
+    let result = get_following(&*d.follows, &user.id, page).await?;
    Ok(Json(serde_json::json!({
        "total": result.total,
        "items": result.items.iter().map(to_user_response).collect::<Vec<_>>()
@@ -162,7 +188,7 @@ pub async fn get_following_handler(
 }

 pub async fn get_followers_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<FeedDeps>,
    Path(param): Path<String>,
    Query(q): Query<PaginationQuery>,
    headers: HeaderMap,
@@ -173,22 +199,22 @@ pub async fn get_followers_handler(
        .unwrap_or("");

    if accept.contains("application/activity+json") {
-        let user = get_user_by_id_or_username(&*s.users, &param).await?;
+        let user = get_user_by_id_or_username(&*d.users, &param).await?;
        let user_id = user.id;
        let page = q.page().try_into().ok();
-        let json = s
+        let json = d
            .federation
            .followers_collection_json(&user_id, page)
            .await?;
        return Ok(([(header::CONTENT_TYPE, "application/activity+json")], json).into_response());
    }

-    let user = get_user_by_username(&*s.users, &param).await?;
+    let user = get_user_by_username(&*d.users, &param).await?;
    let page = PageParams {
        page: q.page(),
        per_page: q.per_page(),
    };
-    let result = get_followers(&*s.follows, &user.id, page).await?;
+    let result = get_followers(&*d.follows, &user.id, page).await?;
    Ok(Json(serde_json::json!({
        "total": result.total,
        "items": result.items.iter().map(to_user_response).collect::<Vec<_>>()
@@ -205,17 +231,17 @@ pub async fn get_followers_handler(
    responses((status = 200, description = "User's public thoughts"))
 )]
 pub async fn user_thoughts_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<FeedDeps>,
    Path(username): Path<String>,
    OptionalAuthUser(viewer): OptionalAuthUser,
    Query(q): Query<PaginationQuery>,
 ) -> Result<Json<serde_json::Value>, ApiError> {
-    let user = get_user_by_username(&*s.users, &username).await?;
+    let user = get_user_by_username(&*d.users, &username).await?;
    let page = PageParams {
        page: q.page(),
        per_page: q.per_page(),
    };
-    let result = get_user_feed(&*s.feed, &user.id, page, viewer.as_ref()).await?;
+    let result = get_user_feed(&*d.feed, &user.id, page, viewer.as_ref()).await?;
    Ok(Json(serde_json::json!({
        "total": result.total,
        "page": result.page,
@@ -225,7 +251,7 @@ pub async fn user_thoughts_handler(
 }

 pub async fn get_popular_tags(
-    State(s): State<AppState>,
+    Deps(d): Deps<FeedDeps>,
    Query(params): Query<std::collections::HashMap<String, String>>,
 ) -> Result<Json<serde_json::Value>, ApiError> {
    let limit: usize = params
@@ -233,7 +259,7 @@ pub async fn get_popular_tags(
        .and_then(|v| v.parse().ok())
        .unwrap_or(api_types::requests::DEFAULT_PER_PAGE as usize);
    let tags = uc_get_popular_tags(
-        &*s.tags,
+        &*d.tags,
        limit.min(api_types::requests::MAX_PER_PAGE as usize),
    )
    .await?;
@@ -254,7 +280,7 @@ pub async fn get_popular_tags(
    responses((status = 200, description = "Thoughts with this tag"))
 )]
 pub async fn tag_thoughts_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<FeedDeps>,
    Path(tag_name): Path<String>,
    OptionalAuthUser(viewer): OptionalAuthUser,
    Query(q): Query<PaginationQuery>,
@@ -263,7 +289,7 @@ pub async fn tag_thoughts_handler(
        page: q.page(),
        per_page: q.per_page(),
    };
-    let result = get_by_tag(&*s.feed, &tag_name, page, viewer.as_ref()).await?;
+    let result = get_by_tag(&*d.feed, &tag_name, page, viewer.as_ref()).await?;
    Ok(Json(serde_json::json!({
        "tag": tag_name,
        "total": result.total,
--- a/crates/presentation/src/handlers/health.rs
+++ b/crates/presentation/src/handlers/health.rs
@@ -1,9 +1,26 @@
-use crate::state::AppState;
-use axum::{extract::State, Json};
+use crate::{
+    extractors::{Deps, FromAppState},
+    state::AppState,
+};
+use axum::Json;
+use domain::ports::UserRepository;
+use std::sync::Arc;
+
+pub struct HealthDeps {
+    pub users: Arc<dyn UserRepository>,
+}
+
+impl FromAppState for HealthDeps {
+    fn from_state(s: &AppState) -> Self {
+        Self {
+            users: s.users.clone(),
+        }
+    }
+}

 #[utoipa::path(get, path = "/health", responses((status = 200, description = "Service health status")))]
-pub async fn health_handler(State(s): State<AppState>) -> Json<serde_json::Value> {
-    let db_ok = s.users.list_with_stats().await.is_ok();
+pub async fn health_handler(Deps(d): Deps<HealthDeps>) -> Json<serde_json::Value> {
+    let db_ok = d.users.list_with_stats().await.is_ok();
    Json(serde_json::json!({
        "status": if db_ok { "ok" } else { "degraded" },
        "db": if db_ok { "connected" } else { "error" },
--- a/crates/presentation/src/handlers/notifications.rs
+++ b/crates/presentation/src/handlers/notifications.rs
@@ -1,28 +1,47 @@
-use crate::{errors::ApiError, extractors::AuthUser, state::AppState};
+use crate::{
+    errors::ApiError,
+    extractors::{AuthUser, Deps, FromAppState},
+    state::AppState,
+};
 use api_types::requests::NotificationUpdateRequest;
 use application::use_cases::notifications::{
    count_unread_notifications, list_notifications as uc_list_notifications,
    mark_all_notifications_read, mark_notification_read as uc_mark_notification_read,
 };
 use axum::{
-    extract::{Path, State},
+    extract::Path,
    http::StatusCode,
    Json,
 };
-use domain::{models::feed::PageParams, value_objects::NotificationId};
+use domain::{
+    models::feed::PageParams, ports::NotificationRepository, value_objects::NotificationId,
+};
+use std::sync::Arc;
 use uuid::Uuid;

+pub struct NotificationsDeps {
+    pub notifications: Arc<dyn NotificationRepository>,
+}
+
+impl FromAppState for NotificationsDeps {
+    fn from_state(s: &AppState) -> Self {
+        Self {
+            notifications: s.notifications.clone(),
+        }
+    }
+}
+
 #[utoipa::path(get, path = "/notifications", responses((status = 200, description = "Notification summary")), security(("bearer_auth" = [])))]
 pub async fn list_notifications(
-    State(s): State<AppState>,
+    Deps(d): Deps<NotificationsDeps>,
    AuthUser(uid): AuthUser,
 ) -> Result<Json<serde_json::Value>, ApiError> {
    let page = PageParams {
        page: 1,
        per_page: 20,
    };
-    let result = uc_list_notifications(&*s.notifications, &uid, page).await?;
-    let unread = count_unread_notifications(&*s.notifications, &uid).await?;
+    let result = uc_list_notifications(&*d.notifications, &uid, page).await?;
+    let unread = count_unread_notifications(&*d.notifications, &uid).await?;
    Ok(Json(serde_json::json!({
        "total": result.total,
        "unread": unread
@@ -31,13 +50,13 @@ pub async fn list_notifications(

 #[utoipa::path(patch, path = "/notifications/{id}", params(("id" = uuid::Uuid, Path, description = "Notification ID")), request_body = NotificationUpdateRequest, responses((status = 204, description = "Marked read")), security(("bearer_auth" = [])))]
 pub async fn mark_notification_read(
-    State(s): State<AppState>,
+    Deps(d): Deps<NotificationsDeps>,
    AuthUser(uid): AuthUser,
    Path(id): Path<Uuid>,
    Json(body): Json<NotificationUpdateRequest>,
 ) -> Result<StatusCode, ApiError> {
    uc_mark_notification_read(
-        &*s.notifications,
+        &*d.notifications,
        &NotificationId::from_uuid(id),
        &uid,
        body.read,
@@ -48,11 +67,11 @@ pub async fn mark_notification_read(

 #[utoipa::path(patch, path = "/notifications", request_body = NotificationUpdateRequest, responses((status = 204, description = "All marked read")), security(("bearer_auth" = [])))]
 pub async fn mark_all_read(
-    State(s): State<AppState>,
+    Deps(d): Deps<NotificationsDeps>,
    AuthUser(uid): AuthUser,
    Json(body): Json<NotificationUpdateRequest>,
 ) -> Result<StatusCode, ApiError> {
-    mark_all_notifications_read(&*s.notifications, &uid, body.read).await?;
+    mark_all_notifications_read(&*d.notifications, &uid, body.read).await?;
    Ok(StatusCode::NO_CONTENT)
 }

--- a/crates/presentation/src/handlers/social.rs
+++ b/crates/presentation/src/handlers/social.rs
@@ -1,49 +1,86 @@
-use crate::{errors::ApiError, extractors::AuthUser, state::AppState};
+use crate::{
+    errors::ApiError,
+    extractors::{AuthUser, Deps, FromAppState},
+    state::AppState,
+};
 use api_types::requests::SetTopFriendsRequest;
 use application::use_cases::profile::{get_top_friends, get_user_by_username, set_top_friends};
 use application::use_cases::social::*;
 use axum::{
-    extract::{Path, State},
+    extract::Path,
    http::StatusCode,
    Json,
 };
-use domain::value_objects::{ThoughtId, UserId};
+use domain::{
+    ports::{
+        BlockRepository, BoostRepository, EventPublisher, FederationActionPort, FollowRepository,
+        LikeRepository, TopFriendRepository, UserRepository,
+    },
+    value_objects::{ThoughtId, UserId},
+};
+use std::sync::Arc;
 use uuid::Uuid;

+pub struct SocialDeps {
+    pub likes: Arc<dyn LikeRepository>,
+    pub boosts: Arc<dyn BoostRepository>,
+    pub follows: Arc<dyn FollowRepository>,
+    pub users: Arc<dyn UserRepository>,
+    pub federation: Arc<dyn FederationActionPort>,
+    pub events: Arc<dyn EventPublisher>,
+    pub blocks: Arc<dyn BlockRepository>,
+    pub top_friends: Arc<dyn TopFriendRepository>,
+}
+
+impl FromAppState for SocialDeps {
+    fn from_state(s: &AppState) -> Self {
+        Self {
+            likes: s.likes.clone(),
+            boosts: s.boosts.clone(),
+            follows: s.follows.clone(),
+            users: s.users.clone(),
+            federation: s.federation.clone(),
+            events: s.events.clone(),
+            blocks: s.blocks.clone(),
+            top_friends: s.top_friends.clone(),
+        }
+    }
+}
+
 #[utoipa::path(post, path = "/thoughts/{id}/like", params(("id" = uuid::Uuid, Path, description = "Thought ID")), responses((status = 204, description = "Liked")), security(("bearer_auth" = [])))]
 pub async fn post_like(
-    State(s): State<AppState>,
+    Deps(d): Deps<SocialDeps>,
    AuthUser(uid): AuthUser,
    Path(id): Path<Uuid>,
 ) -> Result<StatusCode, ApiError> {
-    like_thought(&*s.likes, &*s.events, &uid, &ThoughtId::from_uuid(id)).await?;
+    like_thought(&*d.likes, &*d.events, &uid, &ThoughtId::from_uuid(id)).await?;
    Ok(StatusCode::NO_CONTENT)
 }
 #[utoipa::path(delete, path = "/thoughts/{id}/like", params(("id" = uuid::Uuid, Path, description = "Thought ID")), responses((status = 204, description = "Unliked")), security(("bearer_auth" = [])))]
 pub async fn delete_like(
-    State(s): State<AppState>,
+    Deps(d): Deps<SocialDeps>,
    AuthUser(uid): AuthUser,
    Path(id): Path<Uuid>,
 ) -> Result<StatusCode, ApiError> {
-    unlike_thought(&*s.likes, &*s.events, &uid, &ThoughtId::from_uuid(id)).await?;
+    unlike_thought(&*d.likes, &*d.events, &uid, &ThoughtId::from_uuid(id)).await?;
    Ok(StatusCode::NO_CONTENT)
 }
 #[utoipa::path(post, path = "/thoughts/{id}/boost", params(("id" = uuid::Uuid, Path, description = "Thought ID")), responses((status = 204, description = "Boosted")), security(("bearer_auth" = [])))]
 pub async fn post_boost(
-    State(s): State<AppState>,
+    Deps(d): Deps<SocialDeps>,
    AuthUser(uid): AuthUser,
    Path(id): Path<Uuid>,
 ) -> Result<StatusCode, ApiError> {
-    boost_thought(&*s.boosts, &*s.events, &uid, &ThoughtId::from_uuid(id)).await?;
+    boost_thought(&*d.boosts, &*d.events, &uid, &ThoughtId::from_uuid(id)).await?;
    Ok(StatusCode::NO_CONTENT)
 }
 #[utoipa::path(delete, path = "/thoughts/{id}/boost", params(("id" = uuid::Uuid, Path, description = "Thought ID")), responses((status = 204, description = "Unboosted")), security(("bearer_auth" = [])))]
 pub async fn delete_boost(
-    State(s): State<AppState>,
+    Deps(d): Deps<SocialDeps>,
    AuthUser(uid): AuthUser,
    Path(id): Path<Uuid>,
 ) -> Result<StatusCode, ApiError> {
-    unboost_thought(&*s.boosts, &*s.events, &uid, &ThoughtId::from_uuid(id)).await?;
+    unboost_thought(&*d.boosts, &*d.events, &uid, &ThoughtId::from_uuid(id)).await?;
    Ok(StatusCode::NO_CONTENT)
 }
 #[utoipa::path(
@@ -53,15 +90,15 @@ pub async fn delete_boost(
    security(("bearer_auth" = []))
 )]
 pub async fn post_follow(
-    State(s): State<AppState>,
+    Deps(d): Deps<SocialDeps>,
    AuthUser(uid): AuthUser,
    Path(username): Path<String>,
 ) -> Result<StatusCode, ApiError> {
    follow_actor(
-        &*s.follows,
-        &*s.users,
-        &*s.federation,
-        &*s.events,
+        &*d.follows,
+        &*d.users,
+        &*d.federation,
+        &*d.events,
        &uid,
        &username,
    )
@@ -75,15 +112,15 @@ pub async fn post_follow(
    security(("bearer_auth" = []))
 )]
 pub async fn delete_follow(
-    State(s): State<AppState>,
+    Deps(d): Deps<SocialDeps>,
    AuthUser(uid): AuthUser,
    Path(username): Path<String>,
 ) -> Result<StatusCode, ApiError> {
    unfollow_actor(
-        &*s.follows,
-        &*s.users,
-        &*s.federation,
-        &*s.events,
+        &*d.follows,
+        &*d.users,
+        &*d.federation,
+        &*d.events,
        &uid,
        &username,
    )
@@ -92,39 +129,39 @@ pub async fn delete_follow(
 }
 #[utoipa::path(post, path = "/users/{username}/block", params(("username" = String, Path, description = "Username")), responses((status = 204, description = "Blocked")), security(("bearer_auth" = [])))]
 pub async fn post_block(
-    State(s): State<AppState>,
+    Deps(d): Deps<SocialDeps>,
    AuthUser(uid): AuthUser,
    Path(username): Path<String>,
 ) -> Result<StatusCode, ApiError> {
-    block_by_username(&*s.blocks, &*s.users, &*s.events, &uid, &username).await?;
+    block_by_username(&*d.blocks, &*d.users, &*d.events, &uid, &username).await?;
    Ok(StatusCode::NO_CONTENT)
 }
 #[utoipa::path(delete, path = "/users/{username}/block", params(("username" = String, Path, description = "Username")), responses((status = 204, description = "Unblocked")), security(("bearer_auth" = [])))]
 pub async fn delete_block(
-    State(s): State<AppState>,
+    Deps(d): Deps<SocialDeps>,
    AuthUser(uid): AuthUser,
    Path(username): Path<String>,
 ) -> Result<StatusCode, ApiError> {
-    unblock_by_username(&*s.blocks, &*s.users, &*s.events, &uid, &username).await?;
+    unblock_by_username(&*d.blocks, &*d.users, &*d.events, &uid, &username).await?;
    Ok(StatusCode::NO_CONTENT)
 }
 #[utoipa::path(put, path = "/users/me/top-friends", request_body = SetTopFriendsRequest, responses((status = 204, description = "Top friends updated")), security(("bearer_auth" = [])))]
 pub async fn put_top_friends(
-    State(s): State<AppState>,
+    Deps(d): Deps<SocialDeps>,
    AuthUser(uid): AuthUser,
    Json(body): Json<SetTopFriendsRequest>,
 ) -> Result<StatusCode, ApiError> {
    let ids: Vec<UserId> = body.friend_ids.into_iter().map(UserId::from_uuid).collect();
-    set_top_friends(&*s.top_friends, &uid, ids).await?;
+    set_top_friends(&*d.top_friends, &uid, ids).await?;
    Ok(StatusCode::NO_CONTENT)
 }
 #[utoipa::path(get, path = "/users/{username}/top-friends", params(("username" = String, Path, description = "Username")), responses((status = 200, description = "Top friends list")))]
 pub async fn get_top_friends_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<SocialDeps>,
    Path(username): Path<String>,
 ) -> Result<Json<serde_json::Value>, ApiError> {
-    let user = get_user_by_username(&*s.users, &username).await?;
-    let friends = get_top_friends(&*s.top_friends, &user.id).await?;
+    let user = get_user_by_username(&*d.users, &username).await?;
+    let friends = get_top_friends(&*d.top_friends, &user.id).await?;
    let usernames: Vec<&str> = friends.iter().map(|(_, u)| u.username.as_str()).collect();
    Ok(Json(serde_json::json!({ "topFriends": usernames })))
 }
--- a/crates/presentation/src/handlers/thoughts.rs
+++ b/crates/presentation/src/handlers/thoughts.rs
@@ -1,6 +1,6 @@
 use crate::{
    errors::ApiError,
-    extractors::{AuthUser, OptionalAuthUser},
+    extractors::{AuthUser, Deps, FromAppState, OptionalAuthUser},
    handlers::auth::to_user_response,
    state::AppState,
 };
@@ -12,14 +12,38 @@ use application::use_cases::thoughts::{
    create_thought, delete_thought, edit_thought, get_thought, get_thread, CreateThoughtInput,
 };
 use axum::{
-    extract::{Path, State},
+    extract::Path,
    http::StatusCode,
    response::IntoResponse,
    Json,
 };
-use domain::value_objects::ThoughtId;
+use domain::{
+    ports::{EventPublisher, OutboxWriter, TagRepository, ThoughtRepository, UserRepository},
+    value_objects::ThoughtId,
+};
+use std::sync::Arc;
 use uuid::Uuid;

+pub struct ThoughtsDeps {
+    pub thoughts: Arc<dyn ThoughtRepository>,
+    pub users: Arc<dyn UserRepository>,
+    pub tags: Arc<dyn TagRepository>,
+    pub events: Arc<dyn EventPublisher>,
+    pub outbox: Arc<dyn OutboxWriter>,
+}
+
+impl FromAppState for ThoughtsDeps {
+    fn from_state(s: &AppState) -> Self {
+        Self {
+            thoughts: s.thoughts.clone(),
+            users: s.users.clone(),
+            tags: s.tags.clone(),
+            events: s.events.clone(),
+            outbox: s.outbox.clone(),
+        }
+    }
+}
+
 fn thought_to_json(
    t: &domain::models::thought::Thought,
    author: &domain::models::user::User,
@@ -56,17 +80,17 @@ fn thought_to_json(
    security(("bearer_auth" = []))
 )]
 pub async fn post_thought(
-    State(s): State<AppState>,
+    Deps(d): Deps<ThoughtsDeps>,
    AuthUser(uid): AuthUser,
    Json(body): Json<CreateThoughtRequest>,
 ) -> Result<impl IntoResponse, ApiError> {
    let in_reply_to = body.in_reply_to_id.map(ThoughtId::from_uuid);
    let out = create_thought(
-        &*s.thoughts,
-        &*s.users,
-        &*s.tags,
-        &*s.events,
-        &*s.outbox,
+        &*d.thoughts,
+        &*d.users,
+        &*d.tags,
+        &*d.events,
+        &*d.outbox,
        CreateThoughtInput {
            user_id: uid.clone(),
            content: body.content,
@@ -77,7 +101,7 @@ pub async fn post_thought(
        },
    )
    .await?;
-    let author = s
+    let author = d
        .users
        .find_by_id(&uid)
        .await?
@@ -97,12 +121,12 @@ pub async fn post_thought(
    )
 )]
 pub async fn get_thought_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<ThoughtsDeps>,
    Path(id): Path<Uuid>,
    OptionalAuthUser(_viewer): OptionalAuthUser,
 ) -> Result<Json<serde_json::Value>, ApiError> {
-    let thought = get_thought(&*s.thoughts, &ThoughtId::from_uuid(id)).await?;
-    let author = s
+    let thought = get_thought(&*d.thoughts, &ThoughtId::from_uuid(id)).await?;
+    let author = d
        .users
        .find_by_id(&thought.user_id)
        .await?
@@ -121,11 +145,11 @@ pub async fn get_thought_handler(
    security(("bearer_auth" = []))
 )]
 pub async fn delete_thought_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<ThoughtsDeps>,
    AuthUser(uid): AuthUser,
    Path(id): Path<Uuid>,
 ) -> Result<StatusCode, ApiError> {
-    delete_thought(&*s.thoughts, &*s.events, &*s.outbox, &ThoughtId::from_uuid(id), &uid).await?;
+    delete_thought(&*d.thoughts, &*d.events, &*d.outbox, &ThoughtId::from_uuid(id), &uid).await?;
    Ok(StatusCode::NO_CONTENT)
 }

@@ -141,14 +165,14 @@ pub async fn delete_thought_handler(
    security(("bearer_auth" = []))
 )]
 pub async fn patch_thought(
-    State(s): State<AppState>,
+    Deps(d): Deps<ThoughtsDeps>,
    AuthUser(uid): AuthUser,
    Path(id): Path<Uuid>,
    Json(body): Json<EditThoughtRequest>,
 ) -> Result<StatusCode, ApiError> {
    edit_thought(
-        &*s.thoughts,
-        &*s.events,
+        &*d.thoughts,
+        &*d.events,
        &ThoughtId::from_uuid(id),
        &uid,
        body.content,
@@ -165,13 +189,13 @@ pub async fn patch_thought(
    )
 )]
 pub async fn get_thread_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<ThoughtsDeps>,
    Path(id): Path<Uuid>,
 ) -> Result<Json<Vec<serde_json::Value>>, ApiError> {
-    let thoughts = get_thread(&*s.thoughts, &ThoughtId::from_uuid(id)).await?;
+    let thoughts = get_thread(&*d.thoughts, &ThoughtId::from_uuid(id)).await?;
    let mut items = Vec::new();
    for t in &thoughts {
-        if let Ok(Some(author)) = s.users.find_by_id(&t.user_id).await {
+        if let Ok(Some(author)) = d.users.find_by_id(&t.user_id).await {
            items.push(thought_to_json(t, &author, 0, 0, 0));
        }
    }
--- a/crates/presentation/src/handlers/users.rs
+++ b/crates/presentation/src/handlers/users.rs
@@ -1,6 +1,6 @@
 use crate::{
    errors::ApiError,
-    extractors::{AuthUser, OptionalAuthUser},
+    extractors::{AuthUser, Deps, FromAppState, OptionalAuthUser},
    handlers::auth::to_user_response,
    state::AppState,
 };
@@ -13,11 +13,35 @@ use application::use_cases::profile::{
    get_user as fetch_user, get_user_by_id_or_username, update_profile,
 };
 use axum::{
-    extract::{Path, Query, State},
+    extract::{Path, Query},
    http::{header, HeaderMap},
    response::{IntoResponse, Response},
    Json,
 };
+use domain::ports::{
+    EventPublisher, FederationActionPort, FollowRepository, SearchPort, UserRepository,
+};
+use std::sync::Arc;
+
+pub struct UsersDeps {
+    pub users: Arc<dyn UserRepository>,
+    pub events: Arc<dyn EventPublisher>,
+    pub follows: Arc<dyn FollowRepository>,
+    pub federation: Arc<dyn FederationActionPort>,
+    pub search: Arc<dyn SearchPort>,
+}
+
+impl FromAppState for UsersDeps {
+    fn from_state(s: &AppState) -> Self {
+        Self {
+            users: s.users.clone(),
+            events: s.events.clone(),
+            follows: s.follows.clone(),
+            federation: s.federation.clone(),
+            search: s.search.clone(),
+        }
+    }
+}

 #[utoipa::path(
    get, path = "/users/{username}",
@@ -28,12 +52,12 @@ use axum::{
    )
 )]
 pub async fn get_user(
-    State(s): State<AppState>,
+    Deps(d): Deps<UsersDeps>,
    Path(username): Path<String>,
    OptionalAuthUser(viewer): OptionalAuthUser,
    headers: HeaderMap,
 ) -> Result<Response, ApiError> {
-    let user = get_user_by_id_or_username(&*s.users, &username).await?;
+    let user = get_user_by_id_or_username(&*d.users, &username).await?;

    let accept = headers
        .get(header::ACCEPT)
@@ -41,11 +65,11 @@ pub async fn get_user(
        .unwrap_or("");

    if accept.contains("application/activity+json") {
-        let json = s.federation.actor_json(&user.id).await?;
+        let json = d.federation.actor_json(&user.id).await?;
        Ok(([(header::CONTENT_TYPE, "application/activity+json")], json).into_response())
    } else {
        let is_followed = if let Some(viewer_id) = viewer {
-            s.follows.find(&viewer_id, &user.id).await?.is_some()
+            d.follows.find(&viewer_id, &user.id).await?.is_some()
        } else {
            false
        };
@@ -65,13 +89,13 @@ pub async fn get_user(
    security(("bearer_auth" = []))
 )]
 pub async fn patch_profile(
-    State(s): State<AppState>,
+    Deps(d): Deps<UsersDeps>,
    AuthUser(uid): AuthUser,
    Json(body): Json<UpdateProfileRequest>,
 ) -> Result<Json<UserResponse>, ApiError> {
    update_profile(
-        &*s.users,
-        &*s.events,
+        &*d.users,
+        &*d.events,
        &uid,
        body.display_name,
        body.bio,
@@ -80,7 +104,7 @@ pub async fn patch_profile(
        body.custom_css,
    )
    .await?;
-    let user = fetch_user(&*s.users, &uid).await?;
+    let user = fetch_user(&*d.users, &uid).await?;
    Ok(Json(to_user_response(&user)))
 }

@@ -93,15 +117,15 @@ pub async fn patch_profile(
    security(("bearer_auth" = []))
 )]
 pub async fn get_me(
-    State(s): State<AppState>,
+    Deps(d): Deps<UsersDeps>,
    AuthUser(uid): AuthUser,
 ) -> Result<Json<UserResponse>, ApiError> {
-    let user = fetch_user(&*s.users, &uid).await?;
+    let user = fetch_user(&*d.users, &uid).await?;
    Ok(Json(to_user_response(&user)))
 }

 pub async fn get_me_following(
-    State(s): State<AppState>,
+    Deps(d): Deps<UsersDeps>,
    AuthUser(uid): AuthUser,
    Query(q): Query<PaginationQuery>,
 ) -> Result<Json<serde_json::Value>, ApiError> {
@@ -111,7 +135,7 @@ pub async fn get_me_following(
        page: q.page(),
        per_page: q.per_page(),
    };
-    let result = get_following(&*s.follows, &uid, page).await?;
+    let result = get_following(&*d.follows, &uid, page).await?;
    Ok(Json(serde_json::json!({
        "total": result.total,
        "items": result.items.iter().map(to_user_response).collect::<Vec<_>>(),
@@ -119,7 +143,7 @@ pub async fn get_me_following(
 }

 pub async fn get_users(
-    State(s): State<AppState>,
+    Deps(d): Deps<UsersDeps>,
    Query(params): Query<std::collections::HashMap<String, String>>,
 ) -> Result<Json<serde_json::Value>, ApiError> {
    use domain::models::feed::PageParams;
@@ -134,7 +158,7 @@ pub async fn get_users(
    let page_params = PageParams { page, per_page };

    if let Some(q) = params.get("q").filter(|q| !q.trim().is_empty()) {
-        let result = s.search.search_users(q, &page_params).await?;
+        let result = d.search.search_users(q, &page_params).await?;
        let users: Vec<_> = result
            .items
            .iter()
@@ -145,7 +169,7 @@ pub async fn get_users(
        })));
    }

-    let result = list_users_paginated(&*s.users, page_params).await?;
+    let result = list_users_paginated(&*d.users, page_params).await?;
    let items: Vec<_> = result
        .items
        .iter()
@@ -170,9 +194,9 @@ pub async fn get_users(
 }

 pub async fn get_user_count(
-    State(s): State<AppState>,
+    Deps(d): Deps<UsersDeps>,
 ) -> Result<Json<serde_json::Value>, ApiError> {
-    let count = s.users.count().await?;
+    let count = d.users.count().await?;
    Ok(Json(serde_json::json!({ "count": count })))
 }

@@ -182,10 +206,10 @@ pub struct LookupQuery {
 }

 pub async fn lookup_handler(
-    State(s): State<AppState>,
+    Deps(d): Deps<UsersDeps>,
    Query(q): Query<LookupQuery>,
 ) -> Result<Json<RemoteActorResponse>, ApiError> {
-    let actor = s.federation.lookup_actor(&q.handle).await?;
+    let actor = d.federation.lookup_actor(&q.handle).await?;
    Ok(Json(RemoteActorResponse {
        handle: actor.handle,
        display_name: actor.display_name,
--- a/crates/presentation/src/lib.rs
+++ b/crates/presentation/src/lib.rs
@@ -6,3 +6,5 @@ pub mod routes;
 pub mod state;
 #[cfg(test)]
 pub mod testing;
+
+pub use extractors::{Deps, FromAppState};
--- a/crates/presentation/src/state.rs
+++ b/crates/presentation/src/state.rs
@@ -1,3 +1,4 @@
+use activitypub_base::ActivityPubRepository;
 use domain::ports::*;
 use std::sync::Arc;

--- a/crates/presentation/src/testing.rs
+++ b/crates/presentation/src/testing.rs
@@ -1,10 +1,11 @@
 use crate::state::AppState;
+use activitypub_base::{ActivityPubRepository, ActorApUrls, OutboxEntry};
 use async_trait::async_trait;
 use domain::{
    errors::DomainError,
    ports::{AuthService, GeneratedToken, PasswordHasher},
    testing::{NoOpOutboxWriter, TestStore},
-    value_objects::{PasswordHash, UserId},
+    value_objects::{PasswordHash, ThoughtId, UserId},
 };
 use std::sync::Arc;

@@ -29,6 +30,85 @@ impl PasswordHasher for NoOpHasher {
    }
 }

+/// No-op ActivityPubRepository for presentation layer tests.
+pub struct NoOpApRepo;
+
+#[async_trait]
+impl ActivityPubRepository for NoOpApRepo {
+    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(None)
+    }
+    async fn intern_remote_actor(&self, _actor_ap_url: &str) -> Result<UserId, DomainError> {
+        Err(DomainError::NotFound)
+    }
+    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<(), DomainError> {
+        Ok(())
+    }
+    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(0)
+    }
+    async fn get_thought_ap_id(
+        &self,
+        _thought_id: &ThoughtId,
+    ) -> Result<Option<String>, DomainError> {
+        Ok(None)
+    }
+    async fn get_actor_ap_urls(
+        &self,
+        _user_id: &UserId,
+    ) -> Result<Option<ActorApUrls>, DomainError> {
+        Ok(None)
+    }
+}
+
 pub fn make_state() -> AppState {
    let store = Arc::new(TestStore::default());
    AppState {
@@ -50,7 +130,7 @@ pub fn make_state() -> AppState {
        events: store.clone(),
        outbox: Arc::new(NoOpOutboxWriter),
        federation: store.clone(),
-        ap_repo: store.clone(),
+        ap_repo: Arc::new(NoOpApRepo),
        remote_actor_connections: store.clone(),
        federation_scheduler: store.clone(),
    }
--- a/crates/worker/src/factory.rs
+++ b/crates/worker/src/factory.rs
@@ -5,7 +5,8 @@ use std::sync::Arc;
 use activitypub::ThoughtsObjectHandler;
 use activitypub_base::ActivityPubService;
 use application::services::{FederationEventService, NotificationEventService};
-use domain::ports::{ActivityPubRepository, EventPublisher, OutboundFederationPort};
+use activitypub_base::{ActivityPubRepository, OutboundFederationPort};
+use domain::ports::EventPublisher;
 use postgres::activitypub::PgActivityPubRepository;
 use postgres_federation::{PostgresApUserRepository, PostgresFederationRepository};

--- a/crates/worker/src/outbox_relay.rs
+++ b/crates/worker/src/outbox_relay.rs
@@ -27,25 +27,47 @@ impl OutboxRelay {
        }
    }

+    // NOTE: thoughts.save() and outbox.append() are not in the same DB transaction
+    // (known architectural limitation — fixing requires transaction-sharing between
+    // repositories, a larger refactor).
    async fn process_batch(&self) -> Result<(), sqlx::Error> {
-        let rows = sqlx::query_as::<_, OutboxRow>(
-            "SELECT seq, event_type, payload \
-             FROM outbox_events \
-             WHERE delivered = false \
-             ORDER BY seq ASC \
-             LIMIT 100 \
-             FOR UPDATE SKIP LOCKED",
-        )
-        .fetch_all(&self.pool)
-        .await?;
+        // Process one row at a time inside its own transaction so that
+        // FOR UPDATE SKIP LOCKED actually holds the lock for the duration
+        // of publish + mark_delivered. A batch SELECT without a surrounding
+        // transaction releases locks immediately after autocommit.
+        loop {
+            let mut tx = self.pool.begin().await?;
+
+            let row = sqlx::query_as::<_, OutboxRow>(
+                "SELECT seq, event_type, payload \
+                 FROM outbox_events \
+                 WHERE delivered = false \
+                 ORDER BY seq ASC \
+                 LIMIT 1 \
+                 FOR UPDATE SKIP LOCKED",
+            )
+            .fetch_optional(&mut *tx)
+            .await?;
+
+            let Some(row) = row else {
+                tx.rollback().await?;
+                break;
+            };

-        for row in rows {
            let payload: EventPayload = match serde_json::from_value(row.payload.clone()) {
                Ok(p) => p,
                Err(e) => {
                    tracing::error!(seq = row.seq, event_type = row.event_type, "outbox: failed to deserialize payload: {e}");
                    // Mark delivered to avoid blocking; investigate manually.
-                    self.mark_delivered(row.seq).await?;
+                    sqlx::query(
+                        "UPDATE outbox_events \
+                         SET delivered = true, delivered_at = now() \
+                         WHERE seq = $1",
+                    )
+                    .bind(row.seq)
+                    .execute(&mut *tx)
+                    .await?;
+                    tx.commit().await?;
                    continue;
                }
            };
@@ -54,35 +76,39 @@ impl OutboxRelay {
                Ok(ev) => ev,
                Err(e) => {
                    tracing::error!(seq = row.seq, "outbox: failed to convert to DomainEvent: {e}");
-                    self.mark_delivered(row.seq).await?;
+                    sqlx::query(
+                        "UPDATE outbox_events \
+                         SET delivered = true, delivered_at = now() \
+                         WHERE seq = $1",
+                    )
+                    .bind(row.seq)
+                    .execute(&mut *tx)
+                    .await?;
+                    tx.commit().await?;
                    continue;
                }
            };

            match self.publisher.publish(&domain_event).await {
                Ok(()) => {
-                    self.mark_delivered(row.seq).await?;
+                    sqlx::query(
+                        "UPDATE outbox_events \
+                         SET delivered = true, delivered_at = now() \
+                         WHERE seq = $1",
+                    )
+                    .bind(row.seq)
+                    .execute(&mut *tx)
+                    .await?;
+                    tx.commit().await?;
                    tracing::debug!(seq = row.seq, event_type = row.event_type, "outbox: delivered");
                }
                Err(e) => {
                    tracing::warn!(seq = row.seq, "outbox: publish failed (will retry): {e}");
-                    // Leave delivered=false — will be retried next poll.
+                    tx.rollback().await?; // row stays undelivered, retried next poll
                }
            }
        }

        Ok(())
    }
-
-    async fn mark_delivered(&self, seq: i64) -> Result<(), sqlx::Error> {
-        sqlx::query(
-            "UPDATE outbox_events \
-             SET delivered = true, delivered_at = now() \
-             WHERE seq = $1",
-        )
-        .bind(seq)
-        .execute(&self.pool)
-        .await?;
-        Ok(())
-    }
 }