separation of activitypub

2026-05-09 17:23:06 +02:00
parent 69f6587623
commit 8819266cf9
32 changed files with 2005 additions and 436 deletions
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -5,16 +5,32 @@ version = 4
 [[package]]
 name = "activitypub"
 version = "0.1.0"
+dependencies = [
+ "activitypub-base",
+ "activitypub_federation",
+ "anyhow",
+ "async-trait",
+ "chrono",
+ "domain",
+ "event-publisher",
+ "serde",
+ "serde_json",
+ "tokio",
+ "tracing",
+ "url",
+ "uuid",
+]
+
+[[package]]
+name = "activitypub-base"
+version = "0.1.0"
 dependencies = [
 "activitypub_federation",
 "anyhow",
- "application",
 "async-trait",
 "axum",
 "chrono",
- "domain",
 "enum_delegate",
- "event-publisher",
 "reqwest 0.13.3",
 "serde",
 "serde_json",
@@ -4005,6 +4021,7 @@ name = "sqlite"
 version = "0.1.0"
 dependencies = [
 "activitypub",
+ "activitypub-base",
 "anyhow",
 "async-trait",
 "chrono",
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -9,6 +9,7 @@ members = [
    "crates/adapters/sqlite",
    "crates/adapters/template-askama",
    "crates/adapters/activitypub",
+    "crates/adapters/activitypub-base",
    "crates/application",
    "crates/domain",
    "crates/presentation",
@@ -49,3 +50,4 @@ rss = { path = "crates/adapters/rss" }
 sqlite = { path = "crates/adapters/sqlite" }
 template-askama = { path = "crates/adapters/template-askama" }
 activitypub = { path = "crates/adapters/activitypub" }
+activitypub-base = { path = "crates/adapters/activitypub-base" }
--- a/crates/adapters/activitypub-base/Cargo.toml
+++ b/crates/adapters/activitypub-base/Cargo.toml
@@ -0,0 +1,21 @@
+[package]
+name = "activitypub-base"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]
+tokio = { workspace = true }
+serde = { workspace = true }
+serde_json = { workspace = true }
+reqwest = { workspace = true }
+uuid = { workspace = true }
+chrono = { workspace = true }
+thiserror = { workspace = true }
+anyhow = { workspace = true }
+tracing = { workspace = true }
+async-trait = { workspace = true }
+
+activitypub_federation = "0.7.0-beta.11"
+url = { version = "2", features = ["serde"] }
+enum_delegate = "0.2"
+axum = "0.8"
--- a/crates/adapters/activitypub-base/src/activities.rs
+++ b/crates/adapters/activitypub-base/src/activities.rs
@@ -0,0 +1,341 @@
+use activitypub_federation::{
+    config::Data,
+    fetch::object_id::ObjectId,
+    kinds::activity::{AcceptType, CreateType, DeleteType, FollowType, RejectType, UndoType, UpdateType},
+    traits::Activity,
+};
+use serde::{Deserialize, Serialize};
+use url::Url;
+
+use crate::actors::DbActor;
+use crate::data::FederationData;
+use crate::error::Error;
+use crate::repository::{FollowerStatus, FollowingStatus};
+
+// --- Follow ---
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct FollowActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: FollowType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: ObjectId<DbActor>,
+}
+
+#[async_trait::async_trait]
+impl Activity for FollowActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let target_url = self.object.inner();
+        let target_domain = match (target_url.host_str(), target_url.port()) {
+            (Some(host), Some(port)) => format!("{}:{}", host, port),
+            (Some(host), None) => host.to_string(),
+            _ => return Err(Error::bad_request(anyhow::anyhow!("invalid follow target URL"))),
+        };
+        if target_domain != data.domain {
+            return Err(Error::bad_request(anyhow::anyhow!("follow target is not a local actor")));
+        }
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let _follower = self.actor.dereference(data).await?;
+        let local_actor = self.object.dereference(data).await?;
+
+        data.federation_repo
+            .add_follower(
+                local_actor.user_id,
+                self.actor.inner().as_str(),
+                FollowerStatus::Pending,
+                self.id.as_str(),
+            )
+            .await?;
+
+        tracing::info!(
+            follower = %self.actor.inner(),
+            local_user = %local_actor.user_id,
+            "follow request pending approval"
+        );
+        Ok(())
+    }
+}
+
+// --- Accept ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct AcceptActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: AcceptType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: FollowActivity,
+}
+
+#[async_trait::async_trait]
+impl Activity for AcceptActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let local_user_id = crate::urls::extract_user_id_from_url(self.object.actor.inner())
+            .ok_or_else(|| Error::bad_request(anyhow::anyhow!("invalid actor URL in Follow")))?;
+        data.federation_repo
+            .update_following_status(local_user_id, self.actor.inner().as_str(), FollowingStatus::Accepted)
+            .await?;
+        tracing::info!(remote_actor = %self.actor.inner(), "follow accepted by remote");
+        Ok(())
+    }
+}
+
+// --- Reject ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct RejectActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: RejectType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: FollowActivity,
+}
+
+#[async_trait::async_trait]
+impl Activity for RejectActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        if let Some(user_id) = crate::urls::extract_user_id_from_url(self.object.actor.inner()) {
+            data.federation_repo
+                .remove_following(user_id, self.actor.inner().as_str())
+                .await?;
+        }
+        tracing::info!(actor = %self.actor.inner(), "follow rejected");
+        Ok(())
+    }
+}
+
+// --- Undo ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct UndoActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: UndoType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: FollowActivity,
+}
+
+#[async_trait::async_trait]
+impl Activity for UndoActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        if let Some(user_id) = crate::urls::extract_user_id_from_url(self.object.object.inner()) {
+            data.federation_repo
+                .remove_follower(user_id, self.actor.inner().as_str())
+                .await?;
+        }
+        data.object_handler
+            .on_actor_removed(self.actor.inner())
+            .await
+            .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+        tracing::info!(actor = %self.actor.inner(), "unfollowed");
+        Ok(())
+    }
+}
+
+// --- Create ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct CreateActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: CreateType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: serde_json::Value,
+}
+
+#[async_trait::async_trait]
+impl Activity for CreateActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let ap_id = self.id.clone();
+        let actor_url = self.actor.inner().clone();
+        data.object_handler
+            .on_create(&ap_id, &actor_url, self.object)
+            .await
+            .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+        tracing::info!(actor = %actor_url, "received create activity");
+        Ok(())
+    }
+}
+
+// --- Delete ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct DeleteActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: DeleteType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: Url,
+}
+
+#[async_trait::async_trait]
+impl Activity for DeleteActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let actor_url = self.actor.inner().clone();
+        data.object_handler
+            .on_delete(&self.object, &actor_url)
+            .await
+            .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+        tracing::info!(object = %self.object, "received delete activity");
+        Ok(())
+    }
+}
+
+// --- Update ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct UpdateActivity {
+    pub(crate) id: Url,
+    #[serde(rename = "type", default)]
+    pub(crate) kind: UpdateType,
+    pub(crate) actor: ObjectId<DbActor>,
+    pub(crate) object: serde_json::Value,
+}
+
+#[async_trait::async_trait]
+impl Activity for UpdateActivity {
+    type DataType = FederationData;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.id
+    }
+
+    fn actor(&self) -> &Url {
+        self.actor.inner()
+    }
+
+    async fn verify(&self, _data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        Ok(())
+    }
+
+    async fn receive(self, data: &Data<Self::DataType>) -> Result<(), Self::Error> {
+        let ap_id = self.id.clone();
+        let actor_url = self.actor.inner().clone();
+        data.object_handler
+            .on_update(&ap_id, &actor_url, self.object)
+            .await
+            .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+        tracing::info!(actor = %actor_url, "received update activity");
+        Ok(())
+    }
+}
+
+// --- Inbox dispatch enum ---
+
+#[derive(Debug, Deserialize, Serialize)]
+#[serde(tag = "type")]
+#[enum_delegate::implement(Activity)]
+pub enum InboxActivities {
+    #[serde(rename = "Follow")]
+    Follow(FollowActivity),
+    #[serde(rename = "Accept")]
+    Accept(AcceptActivity),
+    #[serde(rename = "Reject")]
+    Reject(RejectActivity),
+    #[serde(rename = "Undo")]
+    Undo(UndoActivity),
+    #[serde(rename = "Create")]
+    Create(CreateActivity),
+    #[serde(rename = "Delete")]
+    Delete(DeleteActivity),
+    #[serde(rename = "Update")]
+    Update(UpdateActivity),
+}
--- a/crates/adapters/activitypub-base/src/actor_handler.rs
+++ b/crates/adapters/activitypub-base/src/actor_handler.rs
@@ -0,0 +1,21 @@
+use activitypub_federation::{
+    axum::json::FederationJson, config::Data, protocol::context::WithContext, traits::Object,
+};
+use axum::extract::Path;
+
+use crate::actors::{get_local_actor, Person};
+use crate::data::FederationData;
+use crate::error::Error;
+
+pub async fn actor_handler(
+    Path(user_id_str): Path<String>,
+    data: Data<FederationData>,
+) -> Result<FederationJson<WithContext<Person>>, Error> {
+    let uuid = uuid::Uuid::parse_str(&user_id_str)
+        .map_err(|_| Error::bad_request(anyhow::anyhow!("invalid user id")))?;
+
+    let db_actor = get_local_actor(uuid, &data).await?;
+    let person = db_actor.into_json(&data).await?;
+
+    Ok(FederationJson(WithContext::new_default(person)))
+}
--- a/crates/adapters/activitypub-base/src/actors.rs
+++ b/crates/adapters/activitypub-base/src/actors.rs
@@ -0,0 +1,230 @@
+use activitypub_federation::{
+    config::Data,
+    fetch::object_id::ObjectId,
+    http_signatures::generate_actor_keypair,
+    kinds::actor::PersonType,
+    protocol::{public_key::PublicKey, verification::verify_domains_match},
+    traits::{Actor, Object},
+};
+use chrono::{DateTime, Utc};
+use serde::{Deserialize, Serialize};
+use url::Url;
+
+use crate::data::FederationData;
+use crate::error::Error;
+use crate::repository::RemoteActor;
+
+#[derive(Debug, Clone)]
+pub struct DbActor {
+    pub user_id: uuid::Uuid,
+    pub username: String,
+    pub public_key_pem: String,
+    pub private_key_pem: Option<String>,
+    pub inbox_url: Url,
+    pub outbox_url: Url,
+    pub followers_url: Url,
+    pub following_url: Url,
+    pub ap_id: Url,
+    pub last_refreshed_at: DateTime<Utc>,
+}
+
+#[derive(Debug, Clone, Deserialize, Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct Person {
+    #[serde(rename = "type")]
+    kind: PersonType,
+    id: ObjectId<DbActor>,
+    preferred_username: String,
+    inbox: Url,
+    outbox: Url,
+    followers: Url,
+    following: Url,
+    public_key: PublicKey,
+    name: Option<String>,
+}
+
+pub async fn get_local_actor(
+    user_id: uuid::Uuid,
+    data: &Data<FederationData>,
+) -> Result<DbActor, Error> {
+    let user = data
+        .user_repo
+        .find_by_id(user_id)
+        .await
+        .map_err(Error::from)?
+        .ok_or_else(|| Error::not_found(anyhow::anyhow!("user not found: {}", user_id)))?;
+
+    let (public_key, private_key) = match data
+        .federation_repo
+        .get_local_actor_keypair(user_id)
+        .await?
+    {
+        Some(kp) => kp,
+        None => {
+            let kp = generate_actor_keypair()?;
+            data.federation_repo
+                .save_local_actor_keypair(
+                    user_id,
+                    kp.public_key.clone(),
+                    kp.private_key.clone(),
+                )
+                .await?;
+            (kp.public_key, kp.private_key)
+        }
+    };
+
+    let ap_id = crate::urls::actor_url(&data.base_url, user_id);
+    let inbox_url = Url::parse(&format!("{}/inbox", &ap_id)).expect("valid inbox url");
+    let outbox_url = Url::parse(&format!("{}/outbox", &ap_id)).expect("valid outbox url");
+    let followers_url = Url::parse(&format!("{}/followers", &ap_id)).expect("valid followers url");
+    let following_url = Url::parse(&format!("{}/following", &ap_id)).expect("valid following url");
+
+    Ok(DbActor {
+        user_id,
+        username: user.username,
+        public_key_pem: public_key,
+        private_key_pem: Some(private_key),
+        inbox_url,
+        outbox_url,
+        followers_url,
+        following_url,
+        ap_id,
+        last_refreshed_at: Utc::now(),
+    })
+}
+
+#[async_trait::async_trait]
+impl Object for DbActor {
+    type DataType = FederationData;
+    type Kind = Person;
+    type Error = Error;
+
+    fn id(&self) -> &Url {
+        &self.ap_id
+    }
+
+    fn last_refreshed_at(&self) -> Option<DateTime<Utc>> {
+        Some(self.last_refreshed_at)
+    }
+
+    async fn read_from_id(
+        object_id: Url,
+        data: &Data<Self::DataType>,
+    ) -> Result<Option<Self>, Self::Error> {
+        let user_id = match crate::urls::extract_user_id_from_url(&object_id) {
+            Some(id) => id,
+            None => return Ok(None),
+        };
+        let user = match data.user_repo.find_by_id(user_id).await {
+            Ok(Some(u)) => u,
+            _ => return Ok(None),
+        };
+
+        let keypair = data
+            .federation_repo
+            .get_local_actor_keypair(user_id)
+            .await?;
+
+        let (public_key, private_key) = match keypair {
+            Some(kp) => (kp.0, Some(kp.1)),
+            None => return Ok(None),
+        };
+
+        let ap_id = crate::urls::actor_url(&data.base_url, user_id);
+        let inbox_url = Url::parse(&format!("{}/inbox", &ap_id)).expect("valid url");
+        let outbox_url = Url::parse(&format!("{}/outbox", &ap_id)).expect("valid url");
+        let followers_url = Url::parse(&format!("{}/followers", &ap_id)).expect("valid url");
+        let following_url = Url::parse(&format!("{}/following", &ap_id)).expect("valid url");
+
+        Ok(Some(DbActor {
+            user_id,
+            username: user.username,
+            public_key_pem: public_key,
+            private_key_pem: private_key,
+            inbox_url,
+            outbox_url,
+            followers_url,
+            following_url,
+            ap_id,
+            last_refreshed_at: Utc::now(),
+        }))
+    }
+
+    async fn into_json(self, _data: &Data<Self::DataType>) -> Result<Self::Kind, Self::Error> {
+        let public_key = PublicKey {
+            id: format!("{}#main-key", &self.ap_id),
+            owner: self.ap_id.clone(),
+            public_key_pem: self.public_key_pem.clone(),
+        };
+
+        Ok(Person {
+            kind: Default::default(),
+            id: self.ap_id.clone().into(),
+            preferred_username: self.username.clone(),
+            inbox: self.inbox_url.clone(),
+            outbox: self.outbox_url.clone(),
+            followers: self.followers_url.clone(),
+            following: self.following_url.clone(),
+            public_key,
+            name: Some(self.username.clone()),
+        })
+    }
+
+    async fn verify(
+        json: &Self::Kind,
+        expected_domain: &Url,
+        _data: &Data<Self::DataType>,
+    ) -> Result<(), Self::Error> {
+        verify_domains_match(json.id.inner(), expected_domain)?;
+        Ok(())
+    }
+
+    async fn from_json(
+        json: Self::Kind,
+        data: &Data<Self::DataType>,
+    ) -> Result<Self, Self::Error> {
+        let actor = RemoteActor {
+            url: json.id.inner().to_string(),
+            handle: json.preferred_username.clone(),
+            inbox_url: json.inbox.to_string(),
+            shared_inbox_url: None,
+            display_name: json.name.clone(),
+        };
+        data.federation_repo.upsert_remote_actor(actor).await?;
+
+        let url_str = json.id.inner().to_string();
+        let user_id = uuid::Uuid::new_v5(&uuid::Uuid::NAMESPACE_URL, url_str.as_bytes());
+        let ap_id = json.id.inner().clone();
+        let inbox_url = json.inbox.clone();
+        let outbox_url = json.outbox.clone();
+        let followers_url = json.followers.clone();
+        let following_url = json.following.clone();
+
+        Ok(DbActor {
+            user_id,
+            username: json.preferred_username.clone(),
+            public_key_pem: json.public_key.public_key_pem,
+            private_key_pem: None,
+            inbox_url,
+            outbox_url,
+            followers_url,
+            following_url,
+            ap_id,
+            last_refreshed_at: Utc::now(),
+        })
+    }
+}
+
+impl Actor for DbActor {
+    fn public_key_pem(&self) -> &str {
+        &self.public_key_pem
+    }
+
+    fn private_key_pem(&self) -> Option<String> {
+        self.private_key_pem.clone()
+    }
+
+    fn inbox(&self) -> Url {
+        self.inbox_url.clone()
+    }
+}
--- a/crates/adapters/activitypub-base/src/content.rs
+++ b/crates/adapters/activitypub-base/src/content.rs
@@ -0,0 +1,34 @@
+use async_trait::async_trait;
+use url::Url;
+
+#[async_trait]
+pub trait ApObjectHandler: Send + Sync {
+    /// Returns (ap_id, serialized object) for all local content owned by this user.
+    /// Used by outbox (count) and backfill (delivery). Must only return locally-authored content.
+    async fn get_local_objects_for_user(
+        &self,
+        user_id: uuid::Uuid,
+    ) -> anyhow::Result<Vec<(Url, serde_json::Value)>>;
+
+    /// Incoming Create activity — persist remote content.
+    async fn on_create(
+        &self,
+        ap_id: &Url,
+        actor_url: &Url,
+        object: serde_json::Value,
+    ) -> anyhow::Result<()>;
+
+    /// Incoming Update activity — update existing remote content.
+    async fn on_update(
+        &self,
+        ap_id: &Url,
+        actor_url: &Url,
+        object: serde_json::Value,
+    ) -> anyhow::Result<()>;
+
+    /// Incoming Delete activity — remove specific remote content.
+    async fn on_delete(&self, ap_id: &Url, actor_url: &Url) -> anyhow::Result<()>;
+
+    /// Actor unfollowed/was removed — clean up all their remote content.
+    async fn on_actor_removed(&self, actor_url: &Url) -> anyhow::Result<()>;
+}
--- a/crates/adapters/activitypub-base/src/data.rs
+++ b/crates/adapters/activitypub-base/src/data.rs
@@ -0,0 +1,38 @@
+use std::sync::Arc;
+
+use crate::content::ApObjectHandler;
+use crate::repository::FederationRepository;
+use crate::user::ApUserRepository;
+
+#[derive(Clone)]
+pub struct FederationData {
+    pub(crate) federation_repo: Arc<dyn FederationRepository>,
+    pub(crate) user_repo: Arc<dyn ApUserRepository>,
+    pub(crate) object_handler: Arc<dyn ApObjectHandler>,
+    pub(crate) base_url: String,
+    pub(crate) domain: String,
+}
+
+impl FederationData {
+    pub fn new(
+        federation_repo: Arc<dyn FederationRepository>,
+        user_repo: Arc<dyn ApUserRepository>,
+        object_handler: Arc<dyn ApObjectHandler>,
+        base_url: String,
+    ) -> Self {
+        let domain = base_url
+            .trim_start_matches("https://")
+            .trim_start_matches("http://")
+            .split('/')
+            .next()
+            .unwrap_or("")
+            .to_string();
+        Self {
+            federation_repo,
+            user_repo,
+            object_handler,
+            base_url,
+            domain,
+        }
+    }
+}
--- a/crates/adapters/activitypub-base/src/error.rs
+++ b/crates/adapters/activitypub-base/src/error.rs
@@ -0,0 +1,48 @@
+use std::fmt::{Display, Formatter};
+
+use axum::http::StatusCode;
+
+#[derive(Debug)]
+pub struct Error(pub(crate) anyhow::Error, pub(crate) StatusCode);
+
+impl Error {
+    pub fn not_found(e: impl Into<anyhow::Error>) -> Self {
+        Self(e.into(), StatusCode::NOT_FOUND)
+    }
+
+    pub fn bad_request(e: impl Into<anyhow::Error>) -> Self {
+        Self(e.into(), StatusCode::BAD_REQUEST)
+    }
+}
+
+impl Display for Error {
+    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
+        std::fmt::Display::fmt(&self.0, f)
+    }
+}
+
+impl<T> From<T> for Error
+where
+    T: Into<anyhow::Error>,
+{
+    fn from(t: T) -> Self {
+        Error(t.into(), StatusCode::INTERNAL_SERVER_ERROR)
+    }
+}
+
+impl axum::response::IntoResponse for Error {
+    fn into_response(self) -> axum::response::Response {
+        let status = self.1;
+        if status.is_server_error() {
+            tracing::error!(error = %self.0, status = status.as_u16(), "federation error");
+        } else {
+            tracing::debug!(error = %self.0, status = status.as_u16(), "federation response");
+        }
+        let body = if status.is_server_error() {
+            "internal server error".to_string()
+        } else {
+            self.0.to_string()
+        };
+        (status, body).into_response()
+    }
+}
--- a/crates/adapters/activitypub-base/src/federation.rs
+++ b/crates/adapters/activitypub-base/src/federation.rs
@@ -0,0 +1,50 @@
+use activitypub_federation::config::{Data, FederationConfig, FederationMiddleware, UrlVerifier};
+use activitypub_federation::error::Error as FedError;
+use url::Url;
+
+use crate::data::FederationData;
+
+#[derive(Clone)]
+struct PermissiveVerifier;
+
+#[async_trait::async_trait]
+impl UrlVerifier for PermissiveVerifier {
+    async fn verify(&self, _url: &Url) -> Result<(), FedError> {
+        Ok(())
+    }
+}
+
+#[derive(Clone)]
+pub struct ApFederationConfig(pub FederationConfig<FederationData>);
+
+impl ApFederationConfig {
+    pub async fn new(data: FederationData, debug: bool) -> anyhow::Result<Self> {
+        let config = if debug {
+            FederationConfig::builder()
+                .domain(&data.domain)
+                .app_data(data)
+                .debug(true)
+                .http_signature_compat(true)
+                .url_verifier(Box::new(PermissiveVerifier))
+                .build()
+                .await?
+        } else {
+            FederationConfig::builder()
+                .domain(&data.domain)
+                .app_data(data)
+                .debug(false)
+                .http_signature_compat(true)
+                .build()
+                .await?
+        };
+        Ok(Self(config))
+    }
+
+    pub fn to_request_data(&self) -> Data<FederationData> {
+        self.0.to_request_data()
+    }
+
+    pub fn middleware(&self) -> FederationMiddleware<FederationData> {
+        FederationMiddleware::new(self.0.clone())
+    }
+}
--- a/crates/adapters/activitypub-base/src/followers_handler.rs
+++ b/crates/adapters/activitypub-base/src/followers_handler.rs
@@ -0,0 +1,71 @@
+use activitypub_federation::{axum::json::FederationJson, config::Data};
+use axum::extract::Path;
+use serde_json::json;
+
+use crate::data::FederationData;
+use crate::error::Error;
+use crate::repository::FollowerStatus;
+
+fn ordered_collection(id: String, total: usize, items: Vec<String>) -> serde_json::Value {
+    json!({
+        "@context": "https://www.w3.org/ns/activitystreams",
+        "type": "OrderedCollection",
+        "id": id,
+        "totalItems": total,
+        "orderedItems": items,
+    })
+}
+
+pub async fn followers_handler(
+    Path(user_id_str): Path<String>,
+    data: Data<FederationData>,
+) -> Result<FederationJson<serde_json::Value>, Error> {
+    let user_id = uuid::Uuid::parse_str(&user_id_str)
+        .map_err(|_| Error::bad_request(anyhow::anyhow!("invalid user id")))?;
+
+    data.user_repo
+        .find_by_id(user_id)
+        .await
+        .map_err(Error::from)?
+        .ok_or_else(|| Error::not_found(anyhow::anyhow!("user not found")))?;
+
+    let followers = data
+        .federation_repo
+        .get_followers(user_id)
+        .await
+        .map_err(Error::from)?;
+
+    let items: Vec<String> = followers
+        .into_iter()
+        .filter(|f| f.status == FollowerStatus::Accepted)
+        .map(|f| f.actor.url)
+        .collect();
+
+    let id = format!("{}/users/{}/followers", data.base_url, user_id_str);
+    Ok(FederationJson(ordered_collection(id, items.len(), items)))
+}
+
+pub async fn following_handler(
+    Path(user_id_str): Path<String>,
+    data: Data<FederationData>,
+) -> Result<FederationJson<serde_json::Value>, Error> {
+    let user_id = uuid::Uuid::parse_str(&user_id_str)
+        .map_err(|_| Error::bad_request(anyhow::anyhow!("invalid user id")))?;
+
+    data.user_repo
+        .find_by_id(user_id)
+        .await
+        .map_err(Error::from)?
+        .ok_or_else(|| Error::not_found(anyhow::anyhow!("user not found")))?;
+
+    let following = data
+        .federation_repo
+        .get_following(user_id)
+        .await
+        .map_err(Error::from)?;
+
+    let items: Vec<String> = following.into_iter().map(|a| a.url).collect();
+
+    let id = format!("{}/users/{}/following", data.base_url, user_id_str);
+    Ok(FederationJson(ordered_collection(id, items.len(), items)))
+}
--- a/crates/adapters/activitypub-base/src/inbox.rs
+++ b/crates/adapters/activitypub-base/src/inbox.rs
@@ -0,0 +1,20 @@
+use activitypub_federation::{
+    axum::inbox::{receive_activity, ActivityData},
+    config::Data,
+    protocol::context::WithContext,
+};
+
+use crate::activities::InboxActivities;
+use crate::actors::DbActor;
+use crate::data::FederationData;
+use crate::error::Error;
+
+pub async fn inbox_handler(
+    data: Data<FederationData>,
+    activity_data: ActivityData,
+) -> Result<(), Error> {
+    receive_activity::<WithContext<InboxActivities>, DbActor, FederationData>(
+        activity_data, &data,
+    )
+    .await
+}
--- a/crates/adapters/activitypub-base/src/lib.rs
+++ b/crates/adapters/activitypub-base/src/lib.rs
@@ -0,0 +1,23 @@
+pub mod activities;
+pub mod actor_handler;
+pub mod actors;
+pub mod content;
+pub mod data;
+pub mod error;
+pub mod federation;
+pub mod followers_handler;
+pub mod inbox;
+pub mod outbox;
+pub mod repository;
+pub mod service;
+pub mod user;
+pub mod webfinger;
+pub(crate) mod urls;
+
+pub use content::ApObjectHandler;
+pub use data::FederationData;
+pub use error::Error;
+pub use federation::ApFederationConfig;
+pub use repository::{FederationRepository, Follower, FollowerStatus, FollowingStatus, RemoteActor};
+pub use service::ActivityPubService;
+pub use user::{ApUser, ApUserRepository};
--- a/crates/adapters/activitypub-base/src/outbox.rs
+++ b/crates/adapters/activitypub-base/src/outbox.rs
@@ -0,0 +1,48 @@
+use activitypub_federation::{axum::json::FederationJson, config::Data};
+use axum::extract::Path;
+use serde::{Deserialize, Serialize};
+
+use crate::data::FederationData;
+use crate::error::Error;
+
+#[derive(Serialize, Deserialize)]
+#[serde(rename_all = "camelCase")]
+pub struct OrderedCollection {
+    #[serde(rename = "@context")]
+    context: String,
+    #[serde(rename = "type")]
+    kind: String,
+    id: String,
+    total_items: u64,
+    ordered_items: Vec<serde_json::Value>,
+}
+
+pub async fn outbox_handler(
+    Path(user_id_str): Path<String>,
+    data: Data<FederationData>,
+) -> Result<FederationJson<OrderedCollection>, Error> {
+    let uuid = uuid::Uuid::parse_str(&user_id_str)
+        .map_err(|_| Error::bad_request(anyhow::anyhow!("invalid user id")))?;
+
+    data.user_repo
+        .find_by_id(uuid)
+        .await
+        .map_err(Error::from)?
+        .ok_or_else(|| Error::not_found(anyhow::anyhow!("user not found")))?;
+
+    let objects = data
+        .object_handler
+        .get_local_objects_for_user(uuid)
+        .await
+        .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+
+    let outbox_url = format!("{}/users/{}/outbox", data.base_url, user_id_str);
+
+    Ok(FederationJson(OrderedCollection {
+        context: "https://www.w3.org/ns/activitystreams".to_string(),
+        kind: "OrderedCollection".to_string(),
+        id: outbox_url,
+        total_items: objects.len() as u64,
+        ordered_items: vec![],
+    }))
+}
--- a/crates/adapters/activitypub-base/src/repository.rs
+++ b/crates/adapters/activitypub-base/src/repository.rs
@@ -0,0 +1,50 @@
+use anyhow::Result;
+use async_trait::async_trait;
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum FollowerStatus {
+    Pending,
+    Accepted,
+    Rejected,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub enum FollowingStatus {
+    Pending,
+    Accepted,
+}
+
+#[derive(Debug, Clone, PartialEq, Eq)]
+pub struct RemoteActor {
+    pub url: String,
+    pub handle: String,
+    pub inbox_url: String,
+    pub shared_inbox_url: Option<String>,
+    pub display_name: Option<String>,
+}
+
+#[derive(Debug, Clone)]
+pub struct Follower {
+    pub actor: RemoteActor,
+    pub status: FollowerStatus,
+}
+
+#[async_trait]
+pub trait FederationRepository: Send + Sync {
+    async fn add_follower(&self, local_user_id: uuid::Uuid, remote_actor_url: &str, status: FollowerStatus, follow_activity_id: &str) -> Result<()>;
+    async fn get_follower_follow_activity_id(&self, local_user_id: uuid::Uuid, remote_actor_url: &str) -> Result<Option<String>>;
+    async fn remove_follower(&self, local_user_id: uuid::Uuid, remote_actor_url: &str) -> Result<()>;
+    async fn get_followers(&self, local_user_id: uuid::Uuid) -> Result<Vec<Follower>>;
+    async fn update_follower_status(&self, local_user_id: uuid::Uuid, remote_actor_url: &str, status: FollowerStatus) -> Result<()>;
+    async fn add_following(&self, local_user_id: uuid::Uuid, actor: RemoteActor, follow_activity_id: &str) -> Result<()>;
+    async fn get_follow_activity_id(&self, local_user_id: uuid::Uuid, remote_actor_url: &str) -> Result<Option<String>>;
+    async fn remove_following(&self, local_user_id: uuid::Uuid, actor_url: &str) -> Result<()>;
+    async fn get_following(&self, local_user_id: uuid::Uuid) -> Result<Vec<RemoteActor>>;
+    async fn count_following(&self, local_user_id: uuid::Uuid) -> Result<usize>;
+    async fn upsert_remote_actor(&self, actor: RemoteActor) -> Result<()>;
+    async fn get_remote_actor(&self, actor_url: &str) -> Result<Option<RemoteActor>>;
+    async fn get_local_actor_keypair(&self, user_id: uuid::Uuid) -> Result<Option<(String, String)>>;
+    async fn save_local_actor_keypair(&self, user_id: uuid::Uuid, public_key: String, private_key: String) -> Result<()>;
+    async fn get_pending_followers(&self, local_user_id: uuid::Uuid) -> Result<Vec<RemoteActor>>;
+    async fn update_following_status(&self, local_user_id: uuid::Uuid, remote_actor_url: &str, status: FollowingStatus) -> Result<()>;
+}
--- a/crates/adapters/activitypub-base/src/service.rs
+++ b/crates/adapters/activitypub-base/src/service.rs
@@ -0,0 +1,470 @@
+use std::sync::Arc;
+
+use activitypub_federation::{
+    activity_sending::SendActivityTask,
+    fetch::{object_id::ObjectId, webfinger::webfinger_resolve_actor},
+    protocol::context::WithContext,
+    traits::Actor,
+};
+use axum::{routing::get, routing::post, Router};
+use url::Url;
+
+use crate::{
+    activities::{AcceptActivity, CreateActivity, FollowActivity, RejectActivity, UndoActivity},
+    actor_handler::actor_handler,
+    actors::{get_local_actor, DbActor},
+    content::ApObjectHandler,
+    data::FederationData,
+    federation::ApFederationConfig,
+    followers_handler::{followers_handler, following_handler},
+    inbox::inbox_handler,
+    outbox::outbox_handler,
+    repository::{FederationRepository, FollowerStatus, RemoteActor},
+    user::ApUserRepository,
+    urls::activity_url,
+    webfinger::webfinger_handler,
+};
+
+pub(crate) async fn send_with_retry(
+    sends: Vec<SendActivityTask>,
+    data: &activitypub_federation::config::Data<FederationData>,
+) -> Vec<anyhow::Error> {
+    let mut failures = vec![];
+    for send in sends {
+        let mut delay = std::time::Duration::from_secs(1);
+        for attempt in 1..=3u32 {
+            match send.clone().sign_and_send(data).await {
+                Ok(()) => break,
+                Err(e) if attempt < 3 => {
+                    tracing::warn!(attempt, error = %e, "delivery failed, retrying");
+                    tokio::time::sleep(delay).await;
+                    delay *= 2;
+                }
+                Err(e) => {
+                    tracing::error!(attempt, error = %e, "delivery failed permanently");
+                    failures.push(anyhow::anyhow!(e));
+                }
+            }
+        }
+    }
+    failures
+}
+
+pub struct ActivityPubService {
+    federation_config: ApFederationConfig,
+    base_url: String,
+}
+
+impl ActivityPubService {
+    pub async fn new(
+        repo: Arc<dyn FederationRepository>,
+        user_repo: Arc<dyn ApUserRepository>,
+        object_handler: Arc<dyn ApObjectHandler>,
+        base_url: String,
+        debug: bool,
+    ) -> anyhow::Result<Self> {
+        let data = FederationData::new(repo, user_repo, object_handler, base_url.clone());
+        let federation_config = ApFederationConfig::new(data, debug).await?;
+        Ok(Self { federation_config, base_url })
+    }
+
+    pub fn federation_config(&self) -> &ApFederationConfig {
+        &self.federation_config
+    }
+
+    pub fn request_data(&self) -> activitypub_federation::config::Data<FederationData> {
+        self.federation_config.to_request_data()
+    }
+
+    pub async fn actor_json(&self, user_id_str: &str) -> anyhow::Result<String> {
+        use activitypub_federation::traits::Object;
+        let uuid = uuid::Uuid::parse_str(user_id_str)?;
+        let data = self.federation_config.to_request_data();
+        let actor = get_local_actor(uuid, &data)
+            .await
+            .map_err(|e| anyhow::anyhow!("{e}"))?;
+        let person = actor.into_json(&data).await
+            .map_err(|e| anyhow::anyhow!("{e}"))?;
+        Ok(serde_json::to_string(&WithContext::new_default(person))?)
+    }
+
+    pub fn router(&self) -> Router {
+        Router::new()
+            .route("/.well-known/webfinger", get(webfinger_handler))
+            .route("/users/{user_id}", get(actor_handler))
+            .route("/users/{user_id}/inbox", post(inbox_handler))
+            .route("/users/{user_id}/outbox", get(outbox_handler))
+            .route("/users/{user_id}/followers", get(followers_handler))
+            .route("/users/{user_id}/following", get(following_handler))
+            .layer(self.federation_config.middleware())
+    }
+
+    pub async fn follow(&self, local_user_id: uuid::Uuid, handle: &str) -> anyhow::Result<()> {
+        let data = self.federation_config.to_request_data();
+
+        let remote_actor: DbActor = webfinger_resolve_actor(handle, &data)
+            .await
+            .map_err(|e| anyhow::anyhow!("{e}"))?;
+
+        let local_actor = get_local_actor(local_user_id, &data)
+            .await
+            .map_err(|e| anyhow::anyhow!("{e}"))?;
+
+        let follow_id = activity_url(&self.base_url).map_err(|e| anyhow::anyhow!("{e}"))?;
+        let follow_id_str = follow_id.to_string();
+        let follow = FollowActivity {
+            id: follow_id,
+            kind: Default::default(),
+            actor: ObjectId::from(local_actor.ap_id.clone()),
+            object: ObjectId::from(remote_actor.ap_id.clone()),
+        };
+        let follow_with_ctx = WithContext::new_default(follow);
+
+        let sends = SendActivityTask::prepare(
+            &follow_with_ctx,
+            &local_actor,
+            vec![remote_actor.inbox()],
+            &data,
+        )
+        .await?;
+        let failures = send_with_retry(sends, &data).await;
+        if !failures.is_empty() {
+            tracing::warn!(count = failures.len(), "some activity deliveries failed permanently");
+        }
+
+        let remote = RemoteActor {
+            url: remote_actor.ap_id.to_string(),
+            handle: remote_actor.username.clone(),
+            inbox_url: remote_actor.inbox_url.to_string(),
+            shared_inbox_url: None,
+            display_name: Some(remote_actor.username.clone()),
+        };
+        data.federation_repo
+            .add_following(local_user_id, remote, &follow_id_str)
+            .await?;
+
+        Ok(())
+    }
+
+    pub async fn unfollow(&self, local_user_id: uuid::Uuid, actor_url_str: &str) -> anyhow::Result<()> {
+        let data = self.federation_config.to_request_data();
+
+        let remote = data
+            .federation_repo
+            .get_remote_actor(actor_url_str)
+            .await?
+            .ok_or_else(|| anyhow::anyhow!("remote actor not found: {}", actor_url_str))?;
+
+        let local_actor = get_local_actor(local_user_id, &data)
+            .await
+            .map_err(|e| anyhow::anyhow!("{e}"))?;
+
+        let remote_ap_id = Url::parse(actor_url_str)?;
+        let inbox = Url::parse(&remote.inbox_url)?;
+
+        let follow_activity_id_str = data
+            .federation_repo
+            .get_follow_activity_id(local_user_id, actor_url_str)
+            .await?;
+        let follow_id = match follow_activity_id_str {
+            Some(id) => Url::parse(&id)?,
+            None => activity_url(&self.base_url).map_err(|e| anyhow::anyhow!("{e}"))?,
+        };
+        let follow = FollowActivity {
+            id: follow_id,
+            kind: Default::default(),
+            actor: ObjectId::from(local_actor.ap_id.clone()),
+            object: ObjectId::from(remote_ap_id),
+        };
+
+        let undo_id = activity_url(&self.base_url).map_err(|e| anyhow::anyhow!("{e}"))?;
+        let undo = UndoActivity {
+            id: undo_id,
+            kind: Default::default(),
+            actor: ObjectId::from(local_actor.ap_id.clone()),
+            object: follow,
+        };
+
+        let sends = SendActivityTask::prepare(
+            &WithContext::new_default(undo),
+            &local_actor,
+            vec![inbox],
+            &data,
+        )
+        .await?;
+        let failures = send_with_retry(sends, &data).await;
+        if !failures.is_empty() {
+            tracing::warn!(count = failures.len(), "some activity deliveries failed permanently");
+        }
+
+        data.federation_repo
+            .remove_following(local_user_id, actor_url_str)
+            .await?;
+
+        data.object_handler
+            .on_actor_removed(&Url::parse(actor_url_str)?)
+            .await?;
+
+        Ok(())
+    }
+
+    pub async fn accept_follower(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+    ) -> anyhow::Result<()> {
+        let data = self.federation_config.to_request_data();
+        let local_actor = get_local_actor(local_user_id, &data)
+            .await
+            .map_err(|e| anyhow::anyhow!("{e}"))?;
+
+        let remote_actor = data
+            .federation_repo
+            .get_remote_actor(remote_actor_url)
+            .await?
+            .ok_or_else(|| anyhow::anyhow!("remote actor not found"))?;
+
+        let follow_id_str = data
+            .federation_repo
+            .get_follower_follow_activity_id(local_user_id, remote_actor_url)
+            .await?
+            .ok_or_else(|| anyhow::anyhow!("follow activity id not found for {}", remote_actor_url))?;
+        let follow_id = Url::parse(&follow_id_str)?;
+        let follow = FollowActivity {
+            id: follow_id,
+            kind: Default::default(),
+            actor: ObjectId::from(Url::parse(remote_actor_url)?),
+            object: ObjectId::from(local_actor.ap_id.clone()),
+        };
+        let accept = AcceptActivity {
+            id: activity_url(&self.base_url).map_err(|e| anyhow::anyhow!("{e}"))?,
+            kind: Default::default(),
+            actor: ObjectId::from(local_actor.ap_id.clone()),
+            object: follow,
+        };
+
+        data.federation_repo
+            .update_follower_status(local_user_id, remote_actor_url, FollowerStatus::Accepted)
+            .await?;
+
+        let inbox = Url::parse(&remote_actor.inbox_url)?;
+        let sends = SendActivityTask::prepare(
+            &WithContext::new_default(accept),
+            &local_actor,
+            vec![inbox.clone()],
+            &data,
+        )
+        .await?;
+        let failures = send_with_retry(sends, &data).await;
+        if !failures.is_empty() {
+            tracing::warn!("failed to deliver Accept activity, but follower is marked accepted locally");
+        }
+
+        self.spawn_backfill(local_user_id, remote_actor.inbox_url.clone());
+
+        Ok(())
+    }
+
+    pub async fn reject_follower(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+    ) -> anyhow::Result<()> {
+        let data = self.federation_config.to_request_data();
+        let local_actor = get_local_actor(local_user_id, &data)
+            .await
+            .map_err(|e| anyhow::anyhow!("{e}"))?;
+
+        let remote_actor = data
+            .federation_repo
+            .get_remote_actor(remote_actor_url)
+            .await?
+            .ok_or_else(|| anyhow::anyhow!("remote actor not found"))?;
+
+        let follow_id = activity_url(&self.base_url).map_err(|e| anyhow::anyhow!("{e}"))?;
+        let follow = FollowActivity {
+            id: follow_id,
+            kind: Default::default(),
+            actor: ObjectId::from(Url::parse(remote_actor_url)?),
+            object: ObjectId::from(local_actor.ap_id.clone()),
+        };
+        let reject = RejectActivity {
+            id: activity_url(&self.base_url).map_err(|e| anyhow::anyhow!("{e}"))?,
+            kind: Default::default(),
+            actor: ObjectId::from(local_actor.ap_id.clone()),
+            object: follow,
+        };
+
+        let inbox = Url::parse(&remote_actor.inbox_url)?;
+        let sends = SendActivityTask::prepare(
+            &WithContext::new_default(reject),
+            &local_actor,
+            vec![inbox],
+            &data,
+        )
+        .await?;
+        let failures = send_with_retry(sends, &data).await;
+        if !failures.is_empty() {
+            tracing::warn!(count = failures.len(), "some activity deliveries failed permanently");
+        }
+
+        data.federation_repo
+            .remove_follower(local_user_id, remote_actor_url)
+            .await?;
+
+        Ok(())
+    }
+
+    pub async fn get_pending_followers(&self, local_user_id: uuid::Uuid) -> anyhow::Result<Vec<RemoteActor>> {
+        let data = self.federation_config.to_request_data();
+        data.federation_repo.get_pending_followers(local_user_id).await
+    }
+
+    pub async fn get_accepted_followers(&self, local_user_id: uuid::Uuid) -> anyhow::Result<Vec<RemoteActor>> {
+        let data = self.federation_config.to_request_data();
+        let followers = data.federation_repo.get_followers(local_user_id).await?;
+        Ok(followers
+            .into_iter()
+            .filter(|f| f.status == FollowerStatus::Accepted)
+            .map(|f| f.actor)
+            .collect())
+    }
+
+    pub async fn count_accepted_followers(&self, local_user_id: uuid::Uuid) -> anyhow::Result<usize> {
+        let data = self.federation_config.to_request_data();
+        let followers = data.federation_repo.get_followers(local_user_id).await?;
+        Ok(followers.into_iter().filter(|f| f.status == FollowerStatus::Accepted).count())
+    }
+
+    pub async fn get_following(&self, local_user_id: uuid::Uuid) -> anyhow::Result<Vec<RemoteActor>> {
+        let data = self.federation_config.to_request_data();
+        data.federation_repo.get_following(local_user_id).await
+    }
+
+    pub async fn count_following(&self, local_user_id: uuid::Uuid) -> anyhow::Result<usize> {
+        let data = self.federation_config.to_request_data();
+        data.federation_repo.count_following(local_user_id).await
+    }
+
+    pub async fn remove_follower(&self, local_user_id: uuid::Uuid, actor_url: &str) -> anyhow::Result<()> {
+        let data = self.federation_config.to_request_data();
+        data.federation_repo.remove_follower(local_user_id, actor_url).await
+    }
+
+    /// Broadcast a single object to all accepted followers as a Create activity.
+    /// Called by project-specific event handlers when new content is created.
+    pub async fn broadcast_to_followers(
+        &self,
+        local_user_id: uuid::Uuid,
+        ap_id: Url,
+        object: serde_json::Value,
+    ) -> anyhow::Result<()> {
+        let data = self.federation_config.to_request_data();
+        let local_actor = get_local_actor(local_user_id, &data)
+            .await
+            .map_err(|e| anyhow::anyhow!("{e}"))?;
+
+        let followers = data.federation_repo.get_followers(local_user_id).await?;
+        let accepted: Vec<_> = followers
+            .into_iter()
+            .filter(|f| f.status == FollowerStatus::Accepted)
+            .collect();
+
+        if accepted.is_empty() {
+            return Ok(());
+        }
+
+        let create = CreateActivity {
+            id: ap_id.clone(),
+            kind: Default::default(),
+            actor: ObjectId::from(local_actor.ap_id.clone()),
+            object,
+        };
+        let create_with_ctx = WithContext::new_default(create);
+
+        let inboxes: Vec<Url> = accepted
+            .iter()
+            .filter_map(|f| Url::parse(&f.actor.inbox_url).ok())
+            .collect();
+
+        let sends = SendActivityTask::prepare(&create_with_ctx, &local_actor, inboxes, &data).await?;
+        let failures = send_with_retry(sends, &data).await;
+        if !failures.is_empty() {
+            tracing::warn!(count = failures.len(), "some activity deliveries failed permanently");
+        }
+
+        Ok(())
+    }
+
+    fn spawn_backfill(&self, owner_user_id: uuid::Uuid, follower_inbox_url: String) {
+        let config = self.federation_config.clone();
+        let base_url = self.base_url.clone();
+        tokio::spawn(async move {
+            if let Err(e) = ActivityPubService::run_backfill(config, base_url, owner_user_id, follower_inbox_url).await {
+                tracing::warn!(error = %e, "backfill: task failed");
+            }
+        });
+    }
+
+    async fn run_backfill(
+        config: ApFederationConfig,
+        base_url: String,
+        owner_user_id: uuid::Uuid,
+        follower_inbox_url: String,
+    ) -> anyhow::Result<()> {
+        const BATCH_SIZE: usize = 20;
+
+        let data = config.to_request_data();
+        let local_actor = get_local_actor(owner_user_id, &data)
+            .await
+            .map_err(|e| anyhow::anyhow!("{e}"))?;
+        let inbox = Url::parse(&follower_inbox_url)?;
+
+        let mut objects = data.object_handler.get_local_objects_for_user(owner_user_id).await?;
+        objects.reverse(); // oldest first → chronological feed
+
+        let total = objects.len();
+        let mut success_count = 0usize;
+        let mut failure_count = 0usize;
+
+        for chunk in objects.chunks(BATCH_SIZE) {
+            for (ap_id, object_json) in chunk {
+                // Use a stable Create activity ID derived from the object's ap_id
+                let create_id = Url::parse(&format!("{}/activities/create/{}", base_url,
+                    uuid::Uuid::new_v5(&uuid::Uuid::NAMESPACE_URL, ap_id.as_str().as_bytes())
+                ))?;
+
+                let create = CreateActivity {
+                    id: create_id,
+                    kind: Default::default(),
+                    actor: ObjectId::from(local_actor.ap_id.clone()),
+                    object: object_json.clone(),
+                };
+
+                let sends = SendActivityTask::prepare(
+                    &WithContext::new_default(create),
+                    &local_actor,
+                    vec![inbox.clone()],
+                    &data,
+                ).await?;
+                let failures = send_with_retry(sends, &data).await;
+                if failures.is_empty() {
+                    success_count += 1;
+                } else {
+                    failure_count += 1;
+                }
+            }
+            tokio::time::sleep(std::time::Duration::from_millis(100)).await;
+        }
+
+        tracing::info!(
+            user_id = %owner_user_id,
+            follower = %follower_inbox_url,
+            sent = success_count,
+            failed = failure_count,
+            total = total,
+            "backfill complete"
+        );
+        Ok(())
+    }
+}
--- a/crates/adapters/activitypub-base/src/urls.rs
+++ b/crates/adapters/activitypub-base/src/urls.rs
@@ -0,0 +1,20 @@
+use url::Url;
+
+use crate::error::Error;
+
+pub fn extract_user_id_from_url(url: &Url) -> Option<uuid::Uuid> {
+    let path = url.path();
+    path.strip_prefix("/users/")
+        .and_then(|s| s.split('/').next())
+        .and_then(|s| uuid::Uuid::parse_str(s).ok())
+}
+
+pub fn activity_url(base_url: &str) -> Result<Url, Error> {
+    Url::parse(&format!("{}/activities/{}", base_url, uuid::Uuid::new_v4()))
+        .map_err(|e| Error::bad_request(anyhow::anyhow!(e)))
+}
+
+pub fn actor_url(base_url: &str, user_id: uuid::Uuid) -> Url {
+    Url::parse(&format!("{}/users/{}", base_url, user_id))
+        .expect("base_url is always a valid URL prefix")
+}
--- a/crates/adapters/activitypub-base/src/user.rs
+++ b/crates/adapters/activitypub-base/src/user.rs
@@ -0,0 +1,13 @@
+use async_trait::async_trait;
+
+#[derive(Debug, Clone)]
+pub struct ApUser {
+    pub id: uuid::Uuid,
+    pub username: String,
+}
+
+#[async_trait]
+pub trait ApUserRepository: Send + Sync {
+    async fn find_by_id(&self, id: uuid::Uuid) -> anyhow::Result<Option<ApUser>>;
+    async fn find_by_username(&self, username: &str) -> anyhow::Result<Option<ApUser>>;
+}
--- a/crates/adapters/activitypub-base/src/webfinger.rs
+++ b/crates/adapters/activitypub-base/src/webfinger.rs
@@ -0,0 +1,42 @@
+use activitypub_federation::{
+    config::Data,
+    fetch::webfinger::{build_webfinger_response, extract_webfinger_name, Webfinger},
+};
+use axum::{
+    extract::Query,
+    http::header,
+    response::{IntoResponse, Response},
+};
+use serde::Deserialize;
+
+use crate::data::FederationData;
+use crate::error::Error;
+
+#[derive(Deserialize)]
+pub struct WebfingerQuery {
+    resource: String,
+}
+
+pub async fn webfinger_handler(
+    Query(query): Query<WebfingerQuery>,
+    data: Data<FederationData>,
+) -> Result<Response, Error> {
+    let name = extract_webfinger_name(&query.resource, &data)?;
+
+    let user = data
+        .user_repo
+        .find_by_username(name)
+        .await
+        .map_err(Error::from)?
+        .ok_or_else(|| Error::not_found(anyhow::anyhow!("user not found")))?;
+
+    let ap_id = crate::urls::actor_url(&data.base_url, user.id);
+
+    let wf: Webfinger = build_webfinger_response(query.resource, ap_id);
+    let body = serde_json::to_string(&wf)
+        .map_err(|e| Error::from(anyhow::anyhow!(e)))?;
+    Ok((
+        [(header::CONTENT_TYPE, "application/jrd+json")],
+        body,
+    ).into_response())
+}
--- a/crates/adapters/activitypub/Cargo.toml
+++ b/crates/adapters/activitypub/Cargo.toml
@@ -4,15 +4,13 @@ version = "0.1.0"
 edition = "2024"

 [dependencies]
+activitypub-base = { workspace = true }
 domain = { workspace = true }
-application = { workspace = true }
 tokio = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
-reqwest = { workspace = true }
 uuid = { workspace = true }
 chrono = { workspace = true }
-thiserror = { workspace = true }
 anyhow = { workspace = true }
 tracing = { workspace = true }
 async-trait = { workspace = true }
@@ -20,5 +18,3 @@ event-publisher = { workspace = true }

 activitypub_federation = "0.7.0-beta.11"
 url = { version = "2", features = ["serde"] }
-enum_delegate = "0.2"
-axum = "0.8"
--- a/crates/adapters/activitypub/src/event_handler.rs
+++ b/crates/adapters/activitypub/src/event_handler.rs
@@ -1,37 +1,31 @@
-use activitypub_federation::{
-    activity_sending::SendActivityTask,
-    fetch::object_id::ObjectId,
-    protocol::context::WithContext,
-    traits::Object,
-};
 use async_trait::async_trait;
 use domain::{
    errors::DomainError,
    events::DomainEvent,
+    ports::MovieRepository,
    value_objects::{ReviewId, UserId},
 };
 use event_publisher::EventHandler;
-use url::Url;
+use std::sync::Arc;

-use crate::{
-    activities::CreateActivity,
-    actors::get_local_actor,
-    federation::ApFederationConfig,
-    objects::DbReview,
-    repository::FollowerStatus,
-};
+use activitypub_base::ActivityPubService;
+
+use crate::objects::review_to_ap_object;
+use crate::urls::{actor_url, review_url};

 pub struct ActivityPubEventHandler {
-    federation_config: ApFederationConfig,
+    ap_service: Arc<ActivityPubService>,
+    movie_repo: Arc<dyn MovieRepository>,
    base_url: String,
 }

 impl ActivityPubEventHandler {
-    pub fn new(federation_config: ApFederationConfig, base_url: String) -> Self {
-        Self {
-            federation_config,
-            base_url,
-        }
+    pub fn new(
+        ap_service: Arc<ActivityPubService>,
+        movie_repo: Arc<dyn MovieRepository>,
+        base_url: String,
+    ) -> Self {
+        Self { ap_service, movie_repo, base_url }
    }
 }

@@ -39,11 +33,7 @@ impl ActivityPubEventHandler {
 impl EventHandler for ActivityPubEventHandler {
    async fn handle(&self, event: &DomainEvent) -> Result<(), DomainError> {
        match event {
-            DomainEvent::ReviewLogged {
-                review_id,
-                user_id,
-                ..
-            } => self
+            DomainEvent::ReviewLogged { review_id, user_id, .. } => self
                .on_review_logged(user_id, review_id)
                .await
                .map_err(|e| DomainError::InfrastructureError(e.to_string())),
@@ -58,70 +48,29 @@ impl ActivityPubEventHandler {
        user_id: &UserId,
        review_id: &ReviewId,
    ) -> anyhow::Result<()> {
-        let data = self.federation_config.to_request_data();
-
-        let followers = data.federation_repo.get_followers(user_id.clone()).await?;
-        tracing::debug!(user_id = %user_id.value(), count = followers.len(), "AP: got followers for review");
-
-        let accepted: Vec<_> = followers
-            .into_iter()
-            .filter(|f| f.status == FollowerStatus::Accepted)
-            .collect();
-
-        tracing::debug!(accepted = accepted.len(), "AP: accepted followers");
-
-        if accepted.is_empty() {
-            return Ok(());
-        }
-
-        let review = match data.movie_repo.get_review_by_id(review_id).await? {
+        let review = match self.movie_repo.get_review_by_id(review_id).await? {
            Some(r) => r,
            None => return Ok(()),
        };

-        let local_actor = get_local_actor(user_id.clone(), &data)
-            .await
-            .map_err(|e| anyhow::anyhow!("{e}"))?;
+        let ap_id = review_url(&self.base_url, review_id);
+        let actor = actor_url(&self.base_url, user_id.value());

-        let activity_id = crate::urls::activity_url(&self.base_url).map_err(|e| anyhow::anyhow!("{e}"))?;
+        let movie = self.movie_repo.get_movie_by_id(review.movie_id()).await.ok().flatten();
+        let movie_title = movie.as_ref()
+            .map(|m| m.title().value().to_string())
+            .unwrap_or_else(|| "Unknown".to_string());
+        let release_year = movie.as_ref().map(|m| m.release_year().value()).unwrap_or(0);
+        let poster_url = movie.as_ref()
+            .and_then(|m| m.poster_path())
+            .map(|p| format!("{}/posters/{}", self.base_url, p.value()));

-        let db_review = DbReview {
-            ap_id: crate::urls::review_url(&self.base_url, review_id),
-            review,
-        };
-        let object = db_review
-            .into_json(&data)
-            .await
-            .map_err(|e| anyhow::anyhow!("{e}"))?;
+        let obj = review_to_ap_object(&review, ap_id.clone(), actor, movie_title, release_year, poster_url);
+        let json = serde_json::to_value(obj)?;

-        let create = CreateActivity {
-            id: activity_id,
-            kind: Default::default(),
-            actor: ObjectId::from(local_actor.ap_id.clone()),
-            object,
-        };
-        let create_with_ctx = WithContext::new_default(create);
-
-        let inboxes: Vec<Url> = accepted
-            .iter()
-            .filter_map(|f| {
-                let url = Url::parse(&f.actor.inbox_url);
-                if url.is_err() {
-                    tracing::warn!(inbox = %f.actor.inbox_url, "AP: invalid inbox URL, skipping follower");
-                }
-                url.ok()
-            })
-            .collect();
-
-        tracing::debug!(inboxes = inboxes.len(), "AP: delivering to inboxes");
-
-        let sends =
-            SendActivityTask::prepare(&create_with_ctx, &local_actor, inboxes, &data).await?;
-        tracing::debug!(sends = sends.len(), "AP: prepared sends");
-        let failures = crate::service::send_with_retry(sends, &data).await;
-        if !failures.is_empty() {
-            tracing::warn!(count = failures.len(), "some activity deliveries failed permanently");
-        }
+        self.ap_service
+            .broadcast_to_followers(user_id.value(), ap_id, json)
+            .await?;

        Ok(())
    }
--- a/crates/adapters/activitypub/src/lib.rs
+++ b/crates/adapters/activitypub/src/lib.rs
@@ -1,22 +1,17 @@
-pub mod activities;
-pub mod actor_handler;
-pub mod actors;
-pub mod data;
-pub mod error;
 pub mod event_handler;
-pub mod federation;
-pub mod followers_handler;
-pub mod inbox;
 pub mod objects;
-pub mod outbox;
-pub mod repository;
-pub mod service;
+pub mod remote_review_repository;
+pub mod review_handler;
+pub mod user_adapter;
 pub(crate) mod urls;
-pub mod webfinger;

-pub use data::FederationData;
-pub use error::Error;
+// Re-export the generic base types that callers need
+pub use activitypub_base::{
+    ActivityPubService, ApFederationConfig, ApObjectHandler, ApUser, ApUserRepository,
+    FederationData, FederationRepository, Follower, FollowerStatus, FollowingStatus, RemoteActor,
+};
+
 pub use event_handler::ActivityPubEventHandler;
-pub use federation::ApFederationConfig;
-pub use repository::{FederationRepository, Follower, FollowerStatus, RemoteActor};
-pub use service::ActivityPubService;
+pub use remote_review_repository::RemoteReviewRepository;
+pub use review_handler::ReviewObjectHandler;
+pub use user_adapter::DomainUserRepoAdapter;
--- a/crates/adapters/activitypub/src/objects.rs
+++ b/crates/adapters/activitypub/src/objects.rs
@@ -1,33 +1,22 @@
-use activitypub_federation::{
-    config::Data,
-    fetch::object_id::ObjectId,
-    kinds::object::NoteType,
-    protocol::verification::verify_domains_match,
-    traits::Object,
-};
+use activitypub_federation::kinds::object::NoteType;
 use chrono::{DateTime, Utc};
 use serde::{Deserialize, Serialize};
 use url::Url;

-use domain::models::{Review, ReviewSource};
-use domain::value_objects::ReviewId;
-
-use crate::actors::DbActor;
-use crate::data::FederationData;
-use crate::error::Error;
+use domain::models::Review;

 #[derive(Debug, Clone, Deserialize, Serialize)]
 #[serde(rename_all = "camelCase")]
 pub struct ReviewObject {
    #[serde(rename = "type")]
    pub(crate) kind: NoteType,
-    pub(crate) id: ObjectId<DbReview>,
-    pub(crate) attributed_to: ObjectId<DbActor>,
+    pub(crate) id: Url,
+    pub(crate) attributed_to: Url,
    pub(crate) content: String,
    pub(crate) published: DateTime<Utc>,
    pub(crate) movie_title: String,
    #[serde(default)]
-    pub(crate) release_year: u16,   // 0 = unknown; default for old AP messages
+    pub(crate) release_year: u16,
    #[serde(default)]
    pub(crate) poster_url: Option<String>,
    pub(crate) rating: u8,
@@ -35,115 +24,36 @@ pub struct ReviewObject {
    pub(crate) watched_at: DateTime<Utc>,
 }

-#[derive(Debug, Clone)]
-pub struct DbReview {
-    pub review: Review,
-    pub ap_id: Url,
-}
+/// Serialize a local Review into a ReviewObject for AP delivery.
+/// Takes movie metadata explicitly since the handler fetches it separately.
+pub fn review_to_ap_object(
+    review: &Review,
+    ap_id: Url,
+    actor_url: Url,
+    movie_title: String,
+    release_year: u16,
+    poster_url: Option<String>,
+) -> ReviewObject {
+    let stars: String = "\u{2B50}".repeat(review.rating().value() as usize);
+    let comment_text = review.comment().map(|c| c.value().to_string());
+    let year_str = if release_year > 0 { format!(" ({})", release_year) } else { String::new() };
+    let watched_str = format!("Watched: {}", review.watched_at().format("%b %-d, %Y"));
+    let content = match &comment_text {
+        Some(c) => format!("{} {}{}\n{}\n{}", stars, movie_title, year_str, c, watched_str),
+        None => format!("{} {}{}\n{}", stars, movie_title, year_str, watched_str),
+    };

-#[async_trait::async_trait]
-impl Object for DbReview {
-    type DataType = FederationData;
-    type Kind = ReviewObject;
-    type Error = Error;
-
-    fn id(&self) -> &Url {
-        &self.ap_id
-    }
-
-    async fn read_from_id(
-        _object_id: Url,
-        _data: &Data<Self::DataType>,
-    ) -> Result<Option<Self>, Self::Error> {
-        // Incoming activities provide the full object; no need to dereference local reviews
-        Ok(None)
-    }
-
-    async fn into_json(self, data: &Data<Self::DataType>) -> Result<Self::Kind, Self::Error> {
-        let r = &self.review;
-        let ap_id = crate::urls::review_url(&data.base_url, r.id());
-        let actor_url = crate::urls::actor_url(&data.base_url, r.user_id());
-
-        let movie = data.movie_repo.get_movie_by_id(r.movie_id()).await
-            .ok().flatten();
-        let movie_title = movie.as_ref()
-            .map(|m| m.title().value().to_string())
-            .unwrap_or_else(|| "Unknown".to_string());
-        let release_year = movie.as_ref()
-            .map(|m| m.release_year().value())
-            .unwrap_or(0);
-        let poster_url = movie.as_ref()
-            .and_then(|m| m.poster_path())
-            .map(|p| format!("{}/posters/{}", data.base_url, p.value()));
-
-        let stars: String = "\u{2B50}".repeat(r.rating().value() as usize);
-        let comment_text = r.comment().map(|c| c.value().to_string());
-        let year_str = if release_year > 0 { format!(" ({})", release_year) } else { String::new() };
-        let watched_str = format!("Watched: {}", r.watched_at().format("%b %-d, %Y"));
-        let content = match &comment_text {
-            Some(c) => format!("{} {}{}\n{}\n{}", stars, movie_title, year_str, c, watched_str),
-            None => format!("{} {}{}\n{}", stars, movie_title, year_str, watched_str),
-        };
-
-        Ok(ReviewObject {
-            kind: NoteType::default(),
-            id: ap_id.into(),
-            attributed_to: actor_url.into(),
-            content,
-            published: DateTime::from_naive_utc_and_offset(*r.created_at(), Utc),
-            movie_title,
-            release_year,
-            poster_url,
-            rating: r.rating().value(),
-            comment: comment_text,
-            watched_at: DateTime::from_naive_utc_and_offset(*r.watched_at(), Utc),
-        })
-    }
-
-    async fn verify(
-        json: &Self::Kind,
-        expected_domain: &Url,
-        _data: &Data<Self::DataType>,
-    ) -> Result<(), Self::Error> {
-        verify_domains_match(json.attributed_to.inner(), expected_domain)?;
-        Ok(())
-    }
-
-    async fn from_json(
-        json: Self::Kind,
-        data: &Data<Self::DataType>,
-    ) -> Result<Self, Self::Error> {
-        let actor_url = json.attributed_to.inner().to_string();
-
-        let review_id = ReviewId::generate();
-        let movie_id_uuid = uuid::Uuid::new_v5(&uuid::Uuid::NAMESPACE_URL, json.movie_title.as_bytes());
-        let movie_id = domain::value_objects::MovieId::from_uuid(movie_id_uuid);
-        let user_id_uuid = uuid::Uuid::new_v5(&uuid::Uuid::NAMESPACE_URL, actor_url.as_bytes());
-        let user_id = domain::value_objects::UserId::from_uuid(user_id_uuid);
-        let rating = domain::value_objects::Rating::new(json.rating.min(5))
-            .map_err(|e| Error::bad_request(anyhow::anyhow!("{}", e)))?;
-        let comment = json
-            .comment
-            .map(|c| domain::value_objects::Comment::new(c))
-            .transpose()
-            .map_err(|e| Error::bad_request(anyhow::anyhow!("{}", e)))?;
-        let watched_at = json.watched_at.naive_utc();
-        let created_at = json.published.naive_utc();
-
-        let review = Review::from_persistence(
-            review_id,
-            movie_id,
-            user_id,
-            rating,
-            comment,
-            watched_at,
-            created_at,
-            ReviewSource::Remote { actor_url },
-        );
-
-        let ap_id_url = json.id.into_inner();
-        data.federation_repo.save_remote_review(&review, ap_id_url.as_str(), &json.movie_title, json.release_year, json.poster_url.as_deref()).await?;
-
-        Ok(DbReview { review, ap_id: ap_id_url })
+    ReviewObject {
+        kind: NoteType::default(),
+        id: ap_id,
+        attributed_to: actor_url,
+        content,
+        published: DateTime::from_naive_utc_and_offset(*review.created_at(), Utc),
+        movie_title,
+        release_year,
+        poster_url,
+        rating: review.rating().value(),
+        comment: comment_text,
+        watched_at: DateTime::from_naive_utc_and_offset(*review.watched_at(), Utc),
    }
 }
--- a/crates/adapters/activitypub/src/remote_review_repository.rs
+++ b/crates/adapters/activitypub/src/remote_review_repository.rs
@@ -0,0 +1,29 @@
+use anyhow::Result;
+use async_trait::async_trait;
+use chrono::NaiveDateTime;
+use domain::models::Review;
+
+#[async_trait]
+pub trait RemoteReviewRepository: Send + Sync {
+    async fn save_remote_review(
+        &self,
+        review: &Review,
+        ap_id: &str,
+        movie_title: &str,
+        release_year: u16,
+        poster_url: Option<&str>,
+    ) -> Result<()>;
+
+    async fn delete_remote_review(&self, ap_id: &str, actor_url: &str) -> Result<()>;
+
+    async fn update_remote_review(
+        &self,
+        ap_id: &str,
+        actor_url: &str,
+        rating: u8,
+        comment: Option<&str>,
+        watched_at: NaiveDateTime,
+    ) -> Result<()>;
+
+    async fn delete_by_actor(&self, actor_url: &str) -> Result<()>;
+}
--- a/crates/adapters/activitypub/src/review_handler.rs
+++ b/crates/adapters/activitypub/src/review_handler.rs
@@ -0,0 +1,138 @@
+use std::sync::Arc;
+
+use activitypub_base::ApObjectHandler;
+use async_trait::async_trait;
+use domain::{
+    models::{Review, ReviewSource},
+    ports::MovieRepository,
+    value_objects::{Comment, MovieId, Rating, ReviewId, UserId},
+};
+use url::Url;
+
+use crate::objects::{review_to_ap_object, ReviewObject};
+use crate::remote_review_repository::RemoteReviewRepository;
+use crate::urls::{actor_url, review_url};
+
+pub struct ReviewObjectHandler {
+    pub movie_repo: Arc<dyn MovieRepository>,
+    pub review_store: Arc<dyn RemoteReviewRepository>,
+    pub base_url: String,
+}
+
+#[async_trait]
+impl ApObjectHandler for ReviewObjectHandler {
+    async fn get_local_objects_for_user(
+        &self,
+        user_id: uuid::Uuid,
+    ) -> anyhow::Result<Vec<(Url, serde_json::Value)>> {
+        let domain_user_id = UserId::from_uuid(user_id);
+        let history = self.movie_repo.get_user_history(&domain_user_id).await?;
+
+        let mut results = Vec::new();
+        for entry in history {
+            let review = entry.review();
+            if !matches!(review.source(), ReviewSource::Local) {
+                continue;
+            }
+
+            let ap_id = review_url(&self.base_url, review.id());
+            let actor_url = actor_url(&self.base_url, user_id);
+
+            let movie = self.movie_repo.get_movie_by_id(review.movie_id()).await.ok().flatten();
+            let movie_title = movie.as_ref()
+                .map(|m| m.title().value().to_string())
+                .unwrap_or_else(|| "Unknown".to_string());
+            let release_year = movie.as_ref()
+                .map(|m| m.release_year().value())
+                .unwrap_or(0);
+            let poster_url = movie.as_ref()
+                .and_then(|m| m.poster_path())
+                .map(|p| format!("{}/posters/{}", self.base_url, p.value()));
+
+            let obj = review_to_ap_object(review, ap_id.clone(), actor_url, movie_title, release_year, poster_url);
+            let json = serde_json::to_value(obj)?;
+            results.push((ap_id, json));
+        }
+        Ok(results)
+    }
+
+    async fn on_create(
+        &self,
+        _ap_id: &Url,
+        _actor_url: &Url,
+        object: serde_json::Value,
+    ) -> anyhow::Result<()> {
+        let obj: ReviewObject = match serde_json::from_value(object) {
+            Ok(o) => o,
+            Err(e) => {
+                tracing::debug!("ignoring unrecognized Create object: {}", e);
+                return Ok(());
+            }
+        };
+
+        let actor_url_str = obj.attributed_to.to_string();
+        let review_id = ReviewId::generate();
+        let movie_id = MovieId::from_uuid(uuid::Uuid::new_v5(&uuid::Uuid::NAMESPACE_URL, obj.movie_title.as_bytes()));
+        let user_id = UserId::from_uuid(uuid::Uuid::new_v5(&uuid::Uuid::NAMESPACE_URL, actor_url_str.as_bytes()));
+        let rating = Rating::new(obj.rating.min(5))?;
+        let comment = obj.comment.map(Comment::new).transpose()?;
+
+        let review = Review::from_persistence(
+            review_id,
+            movie_id,
+            user_id,
+            rating,
+            comment,
+            obj.watched_at.naive_utc(),
+            obj.published.naive_utc(),
+            ReviewSource::Remote { actor_url: actor_url_str },
+        );
+
+        self.review_store
+            .save_remote_review(&review, obj.id.as_str(), &obj.movie_title, obj.release_year, obj.poster_url.as_deref())
+            .await?;
+
+        Ok(())
+    }
+
+    async fn on_update(
+        &self,
+        ap_id: &Url,
+        actor_url: &Url,
+        object: serde_json::Value,
+    ) -> anyhow::Result<()> {
+        let obj: ReviewObject = match serde_json::from_value(object) {
+            Ok(o) => o,
+            Err(_) => {
+                tracing::debug!(actor = %actor_url, "ignoring non-review Update activity");
+                return Ok(());
+            }
+        };
+
+        if obj.attributed_to != *actor_url {
+            anyhow::bail!("update actor does not match object attributed_to");
+        }
+
+        self.review_store
+            .update_remote_review(
+                ap_id.as_str(),
+                actor_url.as_str(),
+                obj.rating.min(5),
+                obj.comment.as_deref(),
+                obj.watched_at.naive_utc(),
+            )
+            .await?;
+
+        Ok(())
+    }
+
+    async fn on_delete(&self, ap_id: &Url, actor_url: &Url) -> anyhow::Result<()> {
+        self.review_store
+            .delete_remote_review(ap_id.as_str(), actor_url.as_str())
+            .await
+    }
+
+    async fn on_actor_removed(&self, actor_url: &Url) -> anyhow::Result<()> {
+        self.review_store.delete_by_actor(actor_url.as_str()).await
+    }
+}
--- a/crates/adapters/activitypub/src/urls.rs
+++ b/crates/adapters/activitypub/src/urls.rs
@@ -1,26 +1,9 @@
 use url::Url;
-use uuid::Uuid;
-use domain::value_objects::{UserId, ReviewId};
-use crate::error::Error;
-
-/// Extracts a UserId from a URL like `https://example.com/users/{uuid}[/...]`
-pub fn extract_user_id_from_url(url: &Url) -> Option<UserId> {
-    let path = url.path();
-    path.strip_prefix("/users/")
-        .and_then(|s| s.split('/').next())
-        .and_then(|uid_str| Uuid::parse_str(uid_str).ok())
-        .map(UserId::from_uuid)
-}
-
-/// Generates a fresh activity URL: `{base_url}/activities/{uuid}`
-pub fn activity_url(base_url: &str) -> Result<Url, Error> {
-    Url::parse(&format!("{}/activities/{}", base_url, Uuid::new_v4()))
-        .map_err(|e| Error::bad_request(anyhow::anyhow!(e)))
-}
+use domain::value_objects::ReviewId;

 /// Builds the canonical actor URL: `{base_url}/users/{user_id}`
-pub fn actor_url(base_url: &str, user_id: &UserId) -> Url {
-    Url::parse(&format!("{}/users/{}", base_url, user_id.value()))
+pub fn actor_url(base_url: &str, user_id: uuid::Uuid) -> Url {
+    Url::parse(&format!("{}/users/{}", base_url, user_id))
        .expect("base_url is always a valid URL prefix")
 }

@@ -29,10 +12,3 @@ pub fn review_url(base_url: &str, review_id: &ReviewId) -> Url {
    Url::parse(&format!("{}/reviews/{}", base_url, review_id.value()))
        .expect("base_url is always a valid URL prefix")
 }
-
-/// Stable Create-activity URL derived from review ID.
-/// Deterministic so repeated backfills to different followers don't create duplicate posts.
-pub fn create_activity_url(base_url: &str, review_id: &ReviewId) -> Result<Url, Error> {
-    Url::parse(&format!("{}/activities/create/{}", base_url, review_id.value()))
-        .map_err(|e| Error::bad_request(anyhow::anyhow!(e)))
-}
--- a/crates/adapters/activitypub/src/user_adapter.rs
+++ b/crates/adapters/activitypub/src/user_adapter.rs
@@ -0,0 +1,28 @@
+use std::sync::Arc;
+
+use activitypub_base::{ApUser, ApUserRepository};
+use async_trait::async_trait;
+use domain::{ports::UserRepository, value_objects::UserId};
+
+pub struct DomainUserRepoAdapter(pub Arc<dyn UserRepository>);
+
+#[async_trait]
+impl ApUserRepository for DomainUserRepoAdapter {
+    async fn find_by_id(&self, id: uuid::Uuid) -> anyhow::Result<Option<ApUser>> {
+        let user_id = UserId::from_uuid(id);
+        Ok(self.0.find_by_id(&user_id).await?.map(|u| ApUser {
+            id: u.id().value(),
+            username: u.username().value().to_string(),
+        }))
+    }
+
+    async fn find_by_username(&self, username: &str) -> anyhow::Result<Option<ApUser>> {
+        use domain::value_objects::Username;
+        let uname = Username::new(username.to_string())
+            .map_err(|e| anyhow::anyhow!(e.to_string()))?;
+        Ok(self.0.find_by_username(&uname).await?.map(|u| ApUser {
+            id: u.id().value(),
+            username: u.username().value().to_string(),
+        }))
+    }
+}
--- a/crates/adapters/sqlite/Cargo.toml
+++ b/crates/adapters/sqlite/Cargo.toml
@@ -13,6 +13,7 @@ sqlx = { version = "0.8.6", features = [

 domain = { workspace = true }
 activitypub = { workspace = true }
+activitypub-base = { workspace = true }
 anyhow = { workspace = true }
 uuid = { workspace = true }
 chrono = { workspace = true }
--- a/crates/adapters/sqlite/src/federation.rs
+++ b/crates/adapters/sqlite/src/federation.rs
@@ -3,9 +3,9 @@ use async_trait::async_trait;
 use chrono::Utc;
 use sqlx::{Row, SqlitePool};

-use activitypub::repository::{FederationRepository, Follower, FollowerStatus, FollowingStatus, RemoteActor};
+use activitypub_base::{FederationRepository, Follower, FollowerStatus, FollowingStatus, RemoteActor};
+use activitypub::RemoteReviewRepository;
 use domain::models::{Review, ReviewSource};
-use domain::value_objects::UserId;

 use crate::models::datetime_to_str;

@@ -39,12 +39,12 @@ fn str_to_status(s: &str) -> FollowerStatus {
 impl FederationRepository for SqliteFederationRepository {
    async fn add_follower(
        &self,
-        local_user_id: UserId,
+        local_user_id: uuid::Uuid,
        remote_actor_url: &str,
        status: FollowerStatus,
        follow_activity_id: &str,
    ) -> Result<()> {
-        let uid = local_user_id.value().to_string();
+        let uid = local_user_id.to_string();
        let status_str = status_to_str(&status);
        let now = Utc::now().naive_utc();
        let created_at = datetime_to_str(&now);
@@ -69,10 +69,10 @@ impl FederationRepository for SqliteFederationRepository {

    async fn get_follower_follow_activity_id(
        &self,
-        local_user_id: UserId,
+        local_user_id: uuid::Uuid,
        remote_actor_url: &str,
    ) -> Result<Option<String>> {
-        let uid = local_user_id.value().to_string();
+        let uid = local_user_id.to_string();
        let row: Option<Option<String>> = sqlx::query_scalar(
            "SELECT follow_activity_id FROM ap_followers WHERE local_user_id = ? AND remote_actor_url = ?",
        )
@@ -83,22 +83,18 @@ impl FederationRepository for SqliteFederationRepository {
        Ok(row.flatten())
    }

-    async fn remove_follower(&self, local_user_id: UserId, remote_actor_url: &str) -> Result<()> {
-        let uid = local_user_id.value().to_string();
-
-        sqlx::query(
-            "DELETE FROM ap_followers WHERE local_user_id = ? AND remote_actor_url = ?",
-        )
-        .bind(&uid)
-        .bind(remote_actor_url)
-        .execute(&self.pool)
-        .await?;
-
+    async fn remove_follower(&self, local_user_id: uuid::Uuid, remote_actor_url: &str) -> Result<()> {
+        let uid = local_user_id.to_string();
+        sqlx::query("DELETE FROM ap_followers WHERE local_user_id = ? AND remote_actor_url = ?")
+            .bind(&uid)
+            .bind(remote_actor_url)
+            .execute(&self.pool)
+            .await?;
        Ok(())
    }

-    async fn get_followers(&self, local_user_id: UserId) -> Result<Vec<Follower>> {
-        let uid = local_user_id.value().to_string();
+    async fn get_followers(&self, local_user_id: uuid::Uuid) -> Result<Vec<Follower>> {
+        let uid = local_user_id.to_string();

        let rows = sqlx::query(
            "SELECT f.remote_actor_url, f.status,
@@ -122,13 +118,7 @@ impl FederationRepository for SqliteFederationRepository {
                let display_name: Option<String> = row.try_get("display_name").ok().flatten();

                Follower {
-                    actor: RemoteActor {
-                        url,
-                        handle,
-                        inbox_url,
-                        shared_inbox_url,
-                        display_name,
-                    },
+                    actor: RemoteActor { url, handle, inbox_url, shared_inbox_url, display_name },
                    status: str_to_status(&status_str),
                }
            })
@@ -139,11 +129,11 @@ impl FederationRepository for SqliteFederationRepository {

    async fn update_follower_status(
        &self,
-        local_user_id: UserId,
+        local_user_id: uuid::Uuid,
        remote_actor_url: &str,
        status: FollowerStatus,
    ) -> Result<()> {
-        let uid = local_user_id.value().to_string();
+        let uid = local_user_id.to_string();
        let status_str = status_to_str(&status);

        let result = sqlx::query(
@@ -156,18 +146,14 @@ impl FederationRepository for SqliteFederationRepository {
        .await?;

        if result.rows_affected() == 0 {
-            tracing::warn!(
-                local_user_id = %local_user_id.value(),
-                remote_actor_url = remote_actor_url,
-                "update_follower_status: no row found"
-            );
+            tracing::warn!(local_user_id = %local_user_id, remote_actor_url, "update_follower_status: no row found");
        }

        Ok(())
    }

-    async fn add_following(&self, local_user_id: UserId, actor: RemoteActor, follow_activity_id: &str) -> Result<()> {
-        let uid = local_user_id.value().to_string();
+    async fn add_following(&self, local_user_id: uuid::Uuid, actor: RemoteActor, follow_activity_id: &str) -> Result<()> {
+        let uid = local_user_id.to_string();
        let now = Utc::now().naive_utc();
        let created_at = datetime_to_str(&now);

@@ -187,8 +173,8 @@ impl FederationRepository for SqliteFederationRepository {
        Ok(())
    }

-    async fn get_follow_activity_id(&self, local_user_id: UserId, remote_actor_url: &str) -> Result<Option<String>> {
-        let uid = local_user_id.value().to_string();
+    async fn get_follow_activity_id(&self, local_user_id: uuid::Uuid, remote_actor_url: &str) -> Result<Option<String>> {
+        let uid = local_user_id.to_string();
        let row: Option<Option<String>> = sqlx::query_scalar(
            "SELECT follow_activity_id FROM ap_following WHERE local_user_id = ? AND remote_actor_url = ?",
        )
@@ -199,22 +185,18 @@ impl FederationRepository for SqliteFederationRepository {
        Ok(row.flatten())
    }

-    async fn remove_following(&self, local_user_id: UserId, actor_url: &str) -> Result<()> {
-        let uid = local_user_id.value().to_string();
-
-        sqlx::query(
-            "DELETE FROM ap_following WHERE local_user_id = ? AND remote_actor_url = ?",
-        )
-        .bind(&uid)
-        .bind(actor_url)
-        .execute(&self.pool)
-        .await?;
-
+    async fn remove_following(&self, local_user_id: uuid::Uuid, actor_url: &str) -> Result<()> {
+        let uid = local_user_id.to_string();
+        sqlx::query("DELETE FROM ap_following WHERE local_user_id = ? AND remote_actor_url = ?")
+            .bind(&uid)
+            .bind(actor_url)
+            .execute(&self.pool)
+            .await?;
        Ok(())
    }

-    async fn get_following(&self, local_user_id: UserId) -> Result<Vec<RemoteActor>> {
-        let uid = local_user_id.value().to_string();
+    async fn get_following(&self, local_user_id: uuid::Uuid) -> Result<Vec<RemoteActor>> {
+        let uid = local_user_id.to_string();

        let rows = sqlx::query(
            "SELECT a.url, a.handle, a.inbox_url, a.shared_inbox_url, a.display_name
@@ -226,22 +208,17 @@ impl FederationRepository for SqliteFederationRepository {
        .fetch_all(&self.pool)
        .await?;

-        let actors = rows
-            .into_iter()
-            .map(|row| RemoteActor {
-                url: row.get("url"),
-                handle: row.get("handle"),
-                inbox_url: row.get("inbox_url"),
-                shared_inbox_url: row.try_get("shared_inbox_url").ok().flatten(),
-                display_name: row.try_get("display_name").ok().flatten(),
-            })
-            .collect();
-
-        Ok(actors)
+        Ok(rows.into_iter().map(|row| RemoteActor {
+            url: row.get("url"),
+            handle: row.get("handle"),
+            inbox_url: row.get("inbox_url"),
+            shared_inbox_url: row.try_get("shared_inbox_url").ok().flatten(),
+            display_name: row.try_get("display_name").ok().flatten(),
+        }).collect())
    }

-    async fn count_following(&self, local_user_id: UserId) -> Result<usize> {
-        let uid = local_user_id.value().to_string();
+    async fn count_following(&self, local_user_id: uuid::Uuid) -> Result<usize> {
+        let uid = local_user_id.to_string();
        let count: i64 = sqlx::query_scalar(
            "SELECT COUNT(*) FROM ap_following WHERE local_user_id = ? AND status = 'accepted'",
        )
@@ -295,20 +272,17 @@ impl FederationRepository for SqliteFederationRepository {
        }))
    }

-    async fn get_local_actor_keypair(&self, user_id: UserId) -> Result<Option<(String, String)>> {
-        let uid = user_id.value().to_string();
-        let row = sqlx::query(
-            "SELECT public_key, private_key FROM ap_local_actors WHERE user_id = ?",
-        )
-        .bind(&uid)
-        .fetch_optional(&self.pool)
-        .await?;
-
+    async fn get_local_actor_keypair(&self, user_id: uuid::Uuid) -> Result<Option<(String, String)>> {
+        let uid = user_id.to_string();
+        let row = sqlx::query("SELECT public_key, private_key FROM ap_local_actors WHERE user_id = ?")
+            .bind(&uid)
+            .fetch_optional(&self.pool)
+            .await?;
        Ok(row.map(|r| (r.get("public_key"), r.get("private_key"))))
    }

-    async fn save_local_actor_keypair(&self, user_id: UserId, public_key: String, private_key: String) -> Result<()> {
-        let uid = user_id.value().to_string();
+    async fn save_local_actor_keypair(&self, user_id: uuid::Uuid, public_key: String, private_key: String) -> Result<()> {
+        let uid = user_id.to_string();
        let now = Utc::now().naive_utc();
        let created_at = datetime_to_str(&now);

@@ -329,7 +303,70 @@ impl FederationRepository for SqliteFederationRepository {
        Ok(())
    }

-    async fn save_remote_review(&self, review: &Review, ap_id: &str, movie_title: &str, release_year: u16, poster_url: Option<&str>) -> Result<()> {
+    async fn get_pending_followers(&self, local_user_id: uuid::Uuid) -> Result<Vec<RemoteActor>> {
+        let uid = local_user_id.to_string();
+
+        let rows = sqlx::query(
+            "SELECT f.remote_actor_url,
+                    a.handle, a.inbox_url, a.shared_inbox_url, a.display_name
+             FROM ap_followers f
+             LEFT JOIN ap_remote_actors a ON a.url = f.remote_actor_url
+             WHERE f.local_user_id = ? AND f.status = 'pending'",
+        )
+        .bind(&uid)
+        .fetch_all(&self.pool)
+        .await?;
+
+        Ok(rows.into_iter().map(|row| RemoteActor {
+            url: row.get("remote_actor_url"),
+            handle: row.try_get("handle").unwrap_or_default(),
+            inbox_url: row.try_get("inbox_url").unwrap_or_default(),
+            shared_inbox_url: row.try_get("shared_inbox_url").ok().flatten(),
+            display_name: row.try_get("display_name").ok().flatten(),
+        }).collect())
+    }
+
+    async fn update_following_status(
+        &self,
+        local_user_id: uuid::Uuid,
+        remote_actor_url: &str,
+        status: FollowingStatus,
+    ) -> Result<()> {
+        let uid = local_user_id.to_string();
+        let status_str = match status {
+            FollowingStatus::Pending => "pending",
+            FollowingStatus::Accepted => "accepted",
+        };
+
+        let result = sqlx::query(
+            "UPDATE ap_following SET status = ? WHERE local_user_id = ? AND remote_actor_url = ?",
+        )
+        .bind(status_str)
+        .bind(&uid)
+        .bind(remote_actor_url)
+        .execute(&self.pool)
+        .await?;
+
+        if result.rows_affected() == 0 {
+            tracing::warn!(local_user_id = %local_user_id, remote_actor_url, "update_following_status: no row found");
+        }
+
+        Ok(())
+    }
+}
+
+// --- Content-specific repository (movies-diary) ---
+
+#[async_trait]
+impl RemoteReviewRepository for SqliteFederationRepository {
+    async fn save_remote_review(
+        &self,
+        review: &Review,
+        ap_id: &str,
+        movie_title: &str,
+        release_year: u16,
+        poster_url: Option<&str>,
+    ) -> Result<()> {
        let actor_url = match review.source() {
            ReviewSource::Remote { actor_url } => actor_url.clone(),
            ReviewSource::Local => {
@@ -339,9 +376,6 @@ impl FederationRepository for SqliteFederationRepository {

        let movie_id = review.movie_id().value().to_string();

-        // Stub movie so the feed INNER JOIN on movies always resolves.
-        // release_year 0 means unknown — clamp to 1888 (valid ReleaseYear range: 1888-2200).
-        // ON CONFLICT updates poster_path if a newer review carries one.
        let _ = sqlx::query(
            "INSERT INTO movies (id, external_metadata_id, title, release_year, director, poster_path)
             VALUES (?, NULL, ?, ?, NULL, ?)
@@ -350,7 +384,7 @@ impl FederationRepository for SqliteFederationRepository {
        )
        .bind(&movie_id)
        .bind(movie_title)
-        .bind(release_year.max(1888) as i64)  // ReleaseYear requires >= 1888
+        .bind(release_year.max(1888) as i64)
        .bind(poster_url)
        .execute(&self.pool)
        .await?;
@@ -381,7 +415,7 @@ impl FederationRepository for SqliteFederationRepository {
        Ok(())
    }

-    async fn delete_remote_review_by_ap_id(&self, ap_id: &str, actor_url: &str) -> Result<()> {
+    async fn delete_remote_review(&self, ap_id: &str, actor_url: &str) -> Result<()> {
        sqlx::query("DELETE FROM reviews WHERE ap_id = ? AND remote_actor_url = ?")
            .bind(ap_id)
            .bind(actor_url)
@@ -413,66 +447,11 @@ impl FederationRepository for SqliteFederationRepository {
        Ok(())
    }

-    async fn delete_remote_reviews_by_actor(&self, actor_url: &str) -> Result<()> {
+    async fn delete_by_actor(&self, actor_url: &str) -> Result<()> {
        sqlx::query("DELETE FROM reviews WHERE remote_actor_url = ?")
            .bind(actor_url)
            .execute(&self.pool)
            .await?;
        Ok(())
    }
-
-    async fn update_following_status(
-        &self,
-        local_user_id: UserId,
-        remote_actor_url: &str,
-        status: FollowingStatus,
-    ) -> Result<()> {
-        let uid = local_user_id.value().to_string();
-        let status_str = match status {
-            FollowingStatus::Pending => "pending",
-            FollowingStatus::Accepted => "accepted",
-        };
-
-        let result = sqlx::query(
-            "UPDATE ap_following SET status = ? WHERE local_user_id = ? AND remote_actor_url = ?",
-        )
-        .bind(status_str)
-        .bind(&uid)
-        .bind(remote_actor_url)
-        .execute(&self.pool)
-        .await?;
-
-        if result.rows_affected() == 0 {
-            tracing::warn!(
-                local_user_id = %local_user_id.value(),
-                remote_actor_url = remote_actor_url,
-                "update_following_status: no row found"
-            );
-        }
-
-        Ok(())
-    }
-
-    async fn get_pending_followers(&self, local_user_id: UserId) -> Result<Vec<RemoteActor>> {
-        let uid = local_user_id.value().to_string();
-
-        let rows = sqlx::query(
-            "SELECT f.remote_actor_url,
-                    a.handle, a.inbox_url, a.shared_inbox_url, a.display_name
-             FROM ap_followers f
-             LEFT JOIN ap_remote_actors a ON a.url = f.remote_actor_url
-             WHERE f.local_user_id = ? AND f.status = 'pending'",
-        )
-        .bind(&uid)
-        .fetch_all(&self.pool)
-        .await?;
-
-        Ok(rows.into_iter().map(|row| RemoteActor {
-            url: row.get("remote_actor_url"),
-            handle: row.try_get("handle").unwrap_or_default(),
-            inbox_url: row.try_get("inbox_url").unwrap_or_default(),
-            shared_inbox_url: row.try_get("shared_inbox_url").ok().flatten(),
-            display_name: row.try_get("display_name").ok().flatten(),
-        }).collect())
-    }
 }
--- a/crates/presentation/src/extractors.rs
+++ b/crates/presentation/src/extractors.rs
@@ -243,35 +243,34 @@ mod tests {
        sqlx::query("CREATE TABLE IF NOT EXISTS ap_following (local_user_id TEXT NOT NULL, remote_actor_url TEXT NOT NULL, PRIMARY KEY (local_user_id, remote_actor_url))")
            .execute(&pool).await.unwrap();
        let fed_repo = Arc::new(sqlite::SqliteFederationRepository::new(pool));
-        struct DummyUserRepo;
-        #[async_trait::async_trait] impl domain::ports::UserRepository for DummyUserRepo {
-            async fn find_by_email(&self, _: &domain::value_objects::Email) -> Result<Option<domain::models::User>, domain::errors::DomainError> { Ok(None) }
-            async fn save(&self, _: &domain::models::User) -> Result<(), domain::errors::DomainError> { Ok(()) }
-            async fn find_by_id(&self, _: &domain::value_objects::UserId) -> Result<Option<domain::models::User>, domain::errors::DomainError> { Ok(None) }
-            async fn find_by_username(&self, _: &domain::value_objects::Username) -> Result<Option<domain::models::User>, domain::errors::DomainError> { Ok(None) }
-            async fn list_with_stats(&self) -> Result<Vec<domain::models::UserSummary>, domain::errors::DomainError> { Ok(vec![]) }
+
+        struct DummyApUserRepo;
+        #[async_trait::async_trait]
+        impl activitypub::ApUserRepository for DummyApUserRepo {
+            async fn find_by_id(&self, _: uuid::Uuid) -> anyhow::Result<Option<activitypub::ApUser>> { Ok(None) }
+            async fn find_by_username(&self, _: &str) -> anyhow::Result<Option<activitypub::ApUser>> { Ok(None) }
        }
-        struct DummyMovieRepo;
-        #[async_trait::async_trait] impl domain::ports::MovieRepository for DummyMovieRepo {
-            async fn get_movie_by_external_id(&self, _: &domain::value_objects::ExternalMetadataId) -> Result<Option<domain::models::Movie>, domain::errors::DomainError> { Ok(None) }
-            async fn get_movie_by_id(&self, _: &domain::value_objects::MovieId) -> Result<Option<domain::models::Movie>, domain::errors::DomainError> { Ok(None) }
-            async fn get_movies_by_title_and_year(&self, _: &domain::value_objects::MovieTitle, _: &domain::value_objects::ReleaseYear) -> Result<Vec<domain::models::Movie>, domain::errors::DomainError> { Ok(vec![]) }
-            async fn upsert_movie(&self, _: &domain::models::Movie) -> Result<(), domain::errors::DomainError> { Ok(()) }
-            async fn save_review(&self, _: &domain::models::Review) -> Result<domain::events::DomainEvent, domain::errors::DomainError> { panic!() }
-            async fn query_diary(&self, _: &domain::models::DiaryFilter) -> Result<domain::models::collections::Paginated<domain::models::DiaryEntry>, domain::errors::DomainError> { panic!() }
-            async fn get_review_history(&self, _: &domain::value_objects::MovieId) -> Result<domain::models::ReviewHistory, domain::errors::DomainError> { panic!() }
-            async fn get_review_by_id(&self, _: &domain::value_objects::ReviewId) -> Result<Option<domain::models::Review>, domain::errors::DomainError> { Ok(None) }
-            async fn delete_review(&self, _: &domain::value_objects::ReviewId) -> Result<(), domain::errors::DomainError> { Ok(()) }
-            async fn delete_movie(&self, _: &domain::value_objects::MovieId) -> Result<(), domain::errors::DomainError> { Ok(()) }
-            async fn query_activity_feed(&self, _: &domain::models::collections::PageParams) -> Result<domain::models::collections::Paginated<domain::models::FeedEntry>, domain::errors::DomainError> { panic!() }
-            async fn get_user_stats(&self, _: &domain::value_objects::UserId) -> Result<domain::models::UserStats, domain::errors::DomainError> { panic!() }
-            async fn get_user_history(&self, _: &domain::value_objects::UserId) -> Result<Vec<domain::models::DiaryEntry>, domain::errors::DomainError> { Ok(vec![]) }
-            async fn get_user_trends(&self, _: &domain::value_objects::UserId) -> Result<domain::models::UserTrends, domain::errors::DomainError> { panic!() }
+
+        struct DummyObjectHandler;
+        #[async_trait::async_trait]
+        impl activitypub::ApObjectHandler for DummyObjectHandler {
+            async fn get_local_objects_for_user(&self, _: uuid::Uuid) -> anyhow::Result<Vec<(url::Url, serde_json::Value)>> { Ok(vec![]) }
+            async fn on_create(&self, _: &url::Url, _: &url::Url, _: serde_json::Value) -> anyhow::Result<()> { Ok(()) }
+            async fn on_update(&self, _: &url::Url, _: &url::Url, _: serde_json::Value) -> anyhow::Result<()> { Ok(()) }
+            async fn on_delete(&self, _: &url::Url, _: &url::Url) -> anyhow::Result<()> { Ok(()) }
+            async fn on_actor_removed(&self, _: &url::Url) -> anyhow::Result<()> { Ok(()) }
        }
+
        Arc::new(
-            activitypub::ActivityPubService::new(fed_repo, Arc::new(DummyUserRepo), Arc::new(DummyMovieRepo), "http://localhost:3000".to_string(), true)
-                .await
-                .unwrap(),
+            activitypub::ActivityPubService::new(
+                fed_repo,
+                Arc::new(DummyApUserRepo),
+                Arc::new(DummyObjectHandler),
+                "http://localhost:3000".to_string(),
+                true,
+            )
+            .await
+            .unwrap(),
        )
    }

--- a/crates/presentation/src/handlers.rs
+++ b/crates/presentation/src/handlers.rs
@@ -340,7 +340,7 @@ pub mod html {

        let following_count = if is_own_profile {
            if let Some(ref uid) = user_id {
-                state.ap_service.count_following(uid.clone()).await.unwrap_or(0)
+                state.ap_service.count_following(uid.value()).await.unwrap_or(0)
            } else {
                0
            }
@@ -350,7 +350,7 @@ pub mod html {

        let followers_count = if is_own_profile {
            state.ap_service
-                .count_accepted_followers(domain::value_objects::UserId::from_uuid(profile_user_uuid))
+                .count_accepted_followers(profile_user_uuid)
                .await
                .unwrap_or(0)
        } else {
@@ -359,7 +359,7 @@ pub mod html {

        let pending_followers = if is_own_profile {
            state.ap_service
-                .get_pending_followers(domain::value_objects::UserId::from_uuid(profile_user_uuid))
+                .get_pending_followers(profile_user_uuid)
                .await
                .unwrap_or_default()
                .into_iter()
@@ -425,7 +425,7 @@ pub mod html {
        if user_id.value() != profile_user_uuid {
            return StatusCode::FORBIDDEN.into_response();
        }
-        match state.ap_service.follow(user_id.clone(), &form.handle).await {
+        match state.ap_service.follow(user_id.value(), &form.handle).await {
            Ok(()) => Redirect::to(&format!("/users/{}", profile_user_uuid)).into_response(),
            Err(e) => {
                tracing::error!("follow error: {:?}", e);
@@ -444,7 +444,7 @@ pub mod html {
        if user_id.value() != profile_user_uuid {
            return StatusCode::FORBIDDEN.into_response();
        }
-        match state.ap_service.unfollow(user_id.clone(), &form.actor_url).await {
+        match state.ap_service.unfollow(user_id.value(), &form.actor_url).await {
            Ok(()) => Redirect::to(&format!("/users/{}/following-list", profile_user_uuid)).into_response(),
            Err(e) => {
                let msg = encode_error(&e.to_string());
@@ -462,7 +462,7 @@ pub mod html {
        if user_id.value() != profile_user_uuid {
            return StatusCode::FORBIDDEN.into_response();
        }
-        match state.ap_service.accept_follower(user_id, &form.actor_url).await {
+        match state.ap_service.accept_follower(user_id.value(), &form.actor_url).await {
            Ok(_) => Redirect::to(&format!("/users/{}", profile_user_uuid)).into_response(),
            Err(e) => {
                let msg = encode_error(&e.to_string());
@@ -480,7 +480,7 @@ pub mod html {
        if user_id.value() != profile_user_uuid {
            return StatusCode::FORBIDDEN.into_response();
        }
-        match state.ap_service.reject_follower(user_id, &form.actor_url).await {
+        match state.ap_service.reject_follower(user_id.value(), &form.actor_url).await {
            Ok(_) => Redirect::to(&format!("/users/{}", profile_user_uuid)).into_response(),
            Err(e) => {
                let msg = encode_error(&e.to_string());
@@ -501,7 +501,7 @@ pub mod html {
        let mut ctx = build_page_context(&state, Some(user_id.clone())).await;
        ctx.page_title = "Following — Movies Diary".to_string();
        ctx.canonical_url = format!("{}/users/{}/following-list", state.app_ctx.config.base_url, profile_user_uuid);
-        match state.ap_service.get_following(user_id).await {
+        match state.ap_service.get_following(user_id.value()).await {
            Ok(following) => {
                let actors = following.into_iter().map(|a| RemoteActorView {
                    handle: a.handle,
@@ -538,7 +538,7 @@ pub mod html {
        let mut ctx = build_page_context(&state, Some(user_id.clone())).await;
        ctx.page_title = "Followers — Movies Diary".to_string();
        ctx.canonical_url = format!("{}/users/{}/followers-list", state.app_ctx.config.base_url, profile_user_uuid);
-        match state.ap_service.get_accepted_followers(user_id).await {
+        match state.ap_service.get_accepted_followers(user_id.value()).await {
            Ok(followers) => {
                let actors = followers.into_iter().map(|a| RemoteActorView {
                    handle: a.handle,
@@ -572,7 +572,7 @@ pub mod html {
        if user_id.value() != profile_user_uuid {
            return StatusCode::FORBIDDEN.into_response();
        }
-        match state.ap_service.remove_follower(user_id, &form.actor_url).await {
+        match state.ap_service.remove_follower(user_id.value(), &form.actor_url).await {
            Ok(_) => Redirect::to(&format!("/users/{}/followers-list", profile_user_uuid)).into_response(),
            Err(e) => {
                let msg = encode_error(&e.to_string());
--- a/crates/presentation/src/main.rs
+++ b/crates/presentation/src/main.rs
@@ -15,7 +15,7 @@ use auth::{AuthConfig, Argon2PasswordHasher, JwtAuthService};
 use metadata::MetadataClientImpl;
 use poster_fetcher::{PosterFetcherConfig, ReqwestPosterFetcher};
 use poster_storage::{PosterStorageAdapter, StorageConfig};
-use activitypub::ActivityPubService;
+use activitypub::{ActivityPubEventHandler, ActivityPubService, DomainUserRepoAdapter, ReviewObjectHandler};
 use sqlite::{SqliteFederationRepository, SqliteMovieRepository, SqliteUserRepository};
 use rss::RssAdapter;
 use template_askama::AskamaHtmlRenderer;
@@ -94,17 +94,27 @@ async fn wire_dependencies() -> anyhow::Result<AppState> {

    // Federation
    let federation_repo = Arc::new(SqliteFederationRepository::new(pool));
+    let user_repo_adapter = Arc::new(DomainUserRepoAdapter(Arc::clone(&user_repository)));
+    let review_handler = Arc::new(ReviewObjectHandler {
+        movie_repo: Arc::clone(&repository),
+        review_store: Arc::clone(&federation_repo) as Arc<dyn activitypub::RemoteReviewRepository>,
+        base_url: app_config.base_url.clone(),
+    });
    let ap_service = Arc::new(
        ActivityPubService::new(
            federation_repo,
-            Arc::clone(&user_repository),
-            Arc::clone(&repository),
+            user_repo_adapter,
+            review_handler,
            app_config.base_url.clone(),
            cfg!(debug_assertions),
        )
        .await?,
    );
-    let ap_event_handler = ap_service.event_handler();
+    let ap_event_handler = ActivityPubEventHandler::new(
+        Arc::clone(&ap_service),
+        Arc::clone(&repository),
+        app_config.base_url.clone(),
+    );

    let poster_handler = PosterSyncHandler::new(handler_ctx, 3);
    let (event_publisher, event_worker) = create_event_channel(