diff --git a/crates/domain/src/ports.rs b/crates/domain/src/ports.rs
index bfd0726..8395906 100644
--- a/crates/domain/src/ports.rs
+++ b/crates/domain/src/ports.rs
@@ -1,9 +1,11 @@
+use std::collections::HashMap;
+
 use crate::{
     errors::DomainError,
     events::{DomainEvent, EventEnvelope},
     models::{
         api_key::ApiKey,
-        feed::{FeedEntry, PageParams, Paginated, UserSummary},
+        feed::{EngagementStats, FeedEntry, PageParams, Paginated, UserSummary, ViewerContext},
         notification::Notification,
         remote_actor::RemoteActor,
         social::{Block, Boost, Follow, FollowState, Like},
@@ -56,6 +58,8 @@ pub trait UserReader: Send + Sync {
     async fn find_by_email(&self, email: &Email) -> Result<Option<User>, DomainError>;
     async fn list_with_stats(&self) -> Result<Vec<UserSummary>, DomainError>;
     async fn count(&self) -> Result<i64, DomainError>;
+    async fn list_paginated(&self, page: PageParams) -> Result<Paginated<UserSummary>, DomainError>;
+    async fn find_by_ids(&self, ids: &[UserId]) -> Result<HashMap<UserId, User>, DomainError>;
 }
 
 #[async_trait]
@@ -115,6 +119,15 @@ pub trait BoostRepository: Send + Sync {
     async fn count_for_thought(&self, thought_id: &ThoughtId) -> Result<i64, DomainError>;
 }
 
+#[async_trait]
+pub trait EngagementRepository: Send + Sync {
+    async fn get_for_thoughts(
+        &self,
+        thought_ids: &[ThoughtId],
+        viewer_id: Option<&UserId>,
+    ) -> Result<HashMap<ThoughtId, (EngagementStats, Option<ViewerContext>)>, DomainError>;
+}
+
 #[async_trait]
 pub trait FollowRepository: Send + Sync {
     async fn save(&self, follow: &Follow) -> Result<(), DomainError>;
@@ -180,6 +193,11 @@ pub trait ApiKeyRepository: Send + Sync {
     async fn delete(&self, id: &ApiKeyId, user_id: &UserId) -> Result<(), DomainError>;
 }
 
+#[async_trait]
+pub trait ApiKeyService: Send + Sync {
+    async fn validate_key(&self, raw_key: &str) -> Result<Option<UserId>, DomainError>;
+}
+
 #[async_trait]
 pub trait TopFriendRepository: Send + Sync {
     async fn set_top_friends(