diff --git a/codex-rs/analytics/src/reducer.rs b/codex-rs/analytics/src/reducer.rs
index f0eb0ac9a..1be9f624f 100644
--- a/codex-rs/analytics/src/reducer.rs
+++ b/codex-rs/analytics/src/reducer.rs
@@ -1300,7 +1300,7 @@ impl AnalyticsReducer {
                 thread_metadata.session_id.clone(),
                 connection_state.app_server_client.clone(),
                 connection_state.runtime.clone(),
-                thread_metadata.thread_source,
+                thread_metadata.thread_source.clone(),
                 thread_metadata.subagent_source.clone(),
                 thread_metadata.parent_thread_id.clone(),
             ),
diff --git a/codex-rs/app-server/src/extensions.rs b/codex-rs/app-server/src/extensions.rs
index 9e0a6e1c4..4916132c5 100644
--- a/codex-rs/app-server/src/extensions.rs
+++ b/codex-rs/app-server/src/extensions.rs
@@ -26,19 +26,32 @@ use crate::outgoing_message::OutgoingMessageSender;
 use crate::thread_state::ThreadListenerCommand;
 use crate::thread_state::ThreadStateManager;
 
+pub(crate) struct ThreadExtensionDependencies {
+    pub(crate) event_sink: Arc<dyn ExtensionEventSink>,
+    pub(crate) auth_manager: Arc<AuthManager>,
+    pub(crate) state_db: Option<StateDbHandle>,
+    pub(crate) analytics_events_client: AnalyticsEventsClient,
+    pub(crate) thread_manager: Weak<ThreadManager>,
+    pub(crate) goal_service: Arc<GoalService>,
+    pub(crate) executor_skill_provider: Arc<dyn codex_skills_extension::SkillProvider>,
+}
+
 pub(crate) fn thread_extensions<S>(
     guardian_agent_spawner: S,
-    event_sink: Arc<dyn ExtensionEventSink>,
-    auth_manager: Arc<AuthManager>,
-    state_db: Option<StateDbHandle>,
-    analytics_events_client: AnalyticsEventsClient,
-    thread_manager: Weak<ThreadManager>,
-    goal_service: Arc<GoalService>,
-    executor_skill_provider: Arc<dyn codex_skills_extension::SkillProvider>,
+    dependencies: ThreadExtensionDependencies,
 ) -> Arc<ExtensionRegistry<Config>>
 where
     S: AgentSpawner<StartThreadOptions, Spawned = NewThread, Error = CodexErr> + 'static,
 {
+    let ThreadExtensionDependencies {
+        event_sink,
+        auth_manager,
+        state_db,
+        analytics_events_client,
+        thread_manager,
+        goal_service,
+        executor_skill_provider,
+    } = dependencies;
     let mut builder = ExtensionRegistryBuilder::<Config>::with_event_sink(event_sink);
     if let Some(state_db) = state_db {
         codex_goal_extension::install_with_backend(
diff --git a/codex-rs/app-server/src/mcp_refresh.rs b/codex-rs/app-server/src/mcp_refresh.rs
index ff7104883..b5431228d 100644
--- a/codex-rs/app-server/src/mcp_refresh.rs
+++ b/codex-rs/app-server/src/mcp_refresh.rs
@@ -96,6 +96,7 @@ async fn queue_refresh(
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::extensions::ThreadExtensionDependencies;
     use crate::extensions::guardian_agent_spawner;
     use crate::extensions::thread_extensions;
     use async_trait::async_trait;
@@ -193,13 +194,15 @@ mod tests {
                 Arc::clone(&environment_manager),
                 thread_extensions(
                     guardian_agent_spawner(thread_manager.clone()),
-                    Arc::new(NoopExtensionEventSink),
-                    auth_manager.clone(),
-                    Some(state_db.clone()),
-                    codex_analytics::AnalyticsEventsClient::disabled(),
-                    thread_manager.clone(),
-                    Arc::new(codex_goal_extension::GoalService::new()),
-                    Arc::clone(&executor_skill_provider),
+                    ThreadExtensionDependencies {
+                        event_sink: Arc::new(NoopExtensionEventSink),
+                        auth_manager: auth_manager.clone(),
+                        state_db: Some(state_db.clone()),
+                        analytics_events_client: codex_analytics::AnalyticsEventsClient::disabled(),
+                        thread_manager: thread_manager.clone(),
+                        goal_service: Arc::new(codex_goal_extension::GoalService::new()),
+                        executor_skill_provider: Arc::clone(&executor_skill_provider),
+                    },
                 ),
                 /*analytics_events_client*/ None,
                 Arc::clone(&thread_store),
diff --git a/codex-rs/app-server/src/message_processor.rs b/codex-rs/app-server/src/message_processor.rs
index 2069d61c7..6bb5121dc 100644
--- a/codex-rs/app-server/src/message_processor.rs
+++ b/codex-rs/app-server/src/message_processor.rs
@@ -8,6 +8,7 @@ use crate::attestation::app_server_attestation_provider;
 use crate::config_manager::ConfigManager;
 use crate::connection_rpc_gate::ConnectionRpcGate;
 use crate::error_code::invalid_request;
+use crate::extensions::ThreadExtensionDependencies;
 use crate::extensions::app_server_extension_event_sink;
 use crate::extensions::guardian_agent_spawner;
 use crate::extensions::thread_extensions;
@@ -324,13 +325,18 @@ impl MessageProcessor {
                 environment_manager,
                 thread_extensions(
                     guardian_agent_spawner(thread_manager.clone()),
-                    app_server_extension_event_sink(outgoing.clone(), thread_state_manager.clone()),
-                    auth_manager.clone(),
-                    state_db.clone(),
-                    analytics_events_client.clone(),
-                    thread_manager.clone(),
-                    Arc::clone(&goal_service),
-                    Arc::clone(&executor_skill_provider),
+                    ThreadExtensionDependencies {
+                        event_sink: app_server_extension_event_sink(
+                            outgoing.clone(),
+                            thread_state_manager.clone(),
+                        ),
+                        auth_manager: auth_manager.clone(),
+                        state_db: state_db.clone(),
+                        analytics_events_client: analytics_events_client.clone(),
+                        thread_manager: thread_manager.clone(),
+                        goal_service: Arc::clone(&goal_service),
+                        executor_skill_provider: Arc::clone(&executor_skill_provider),
+                    },
                 ),
                 Some(analytics_events_client.clone()),
                 Arc::clone(&thread_store),
diff --git a/codex-rs/app-server/tests/suite/v2/turn_start.rs b/codex-rs/app-server/tests/suite/v2/turn_start.rs
index 508093799..823851b71 100644
--- a/codex-rs/app-server/tests/suite/v2/turn_start.rs
+++ b/codex-rs/app-server/tests/suite/v2/turn_start.rs
@@ -591,7 +591,15 @@ async fn turn_start_emits_thread_scoped_warning_notification_for_trimmed_skills(
     write_test_skill(codex_home.path(), "alpha-skill")?;
     write_test_skill(codex_home.path(), "beta-skill")?;
 
-    let mut mcp = TestAppServer::new(codex_home.path()).await?;
+    let isolated_home = codex_home.path().to_string_lossy();
+    let mut mcp = TestAppServer::new_with_env(
+        codex_home.path(),
+        &[
+            ("HOME", Some(isolated_home.as_ref())),
+            ("USERPROFILE", Some(isolated_home.as_ref())),
+        ],
+    )
+    .await?;
     timeout(DEFAULT_READ_TIMEOUT, mcp.initialize()).await??;
 
     let thread_req = mcp