diff --git a/codex-rs/analytics/src/reducer.rs b/codex-rs/analytics/src/reducer.rs
index 33e89df011..e9fd03f924 100644
--- a/codex-rs/analytics/src/reducer.rs
+++ b/codex-rs/analytics/src/reducer.rs
@@ -74,8 +74,7 @@ pub(crate) struct AnalyticsReducer {
     requests: HashMap<(u64, RequestId), RequestState>,
     turns: HashMap<String, TurnState>,
     connections: HashMap<u64, ConnectionState>,
-    thread_connections: HashMap<String, u64>,
-    thread_metadata: HashMap<String, ThreadMetadataState>,
+    threads: HashMap<String, ThreadAnalyticsState>,
 }
 
 struct ConnectionState {
@@ -83,6 +82,84 @@ struct ConnectionState {
     runtime: CodexRuntimeMetadata,
 }
 
+#[derive(Default)]
+struct ThreadAnalyticsState {
+    connection_id: Option<u64>,
+    metadata: Option<ThreadMetadataState>,
+}
+
+struct ResolvedAnalyticsContext<'a> {
+    connection_state: &'a ConnectionState,
+    thread_metadata: Option<&'a ThreadMetadataState>,
+}
+
+enum AnalyticsConnectionSource<'a> {
+    Thread(&'a str),
+    Known(u64),
+    MaybeKnown(Option<u64>),
+}
+
+enum ThreadMetadataRequirement<'a> {
+    NotRequired,
+    Required(&'a str),
+}
+
+struct AnalyticsDropSite<'a> {
+    event_name: &'static str,
+    thread_id: &'a str,
+    turn_id: Option<&'a str>,
+    review_id: Option<&'a str>,
+    item_id: Option<&'a str>,
+}
+
+impl<'a> AnalyticsDropSite<'a> {
+    fn guardian(input: &'a GuardianReviewEventParams) -> Self {
+        Self {
+            event_name: "guardian",
+            thread_id: &input.thread_id,
+            turn_id: Some(&input.turn_id),
+            review_id: Some(&input.review_id),
+            item_id: None,
+        }
+    }
+
+    fn compaction(input: &'a CodexCompactionEvent) -> Self {
+        Self {
+            event_name: "compaction",
+            thread_id: &input.thread_id,
+            turn_id: Some(&input.turn_id),
+            review_id: None,
+            item_id: None,
+        }
+    }
+
+    fn turn_steer(thread_id: &'a str) -> Self {
+        Self {
+            event_name: "turn steer",
+            thread_id,
+            turn_id: None,
+            review_id: None,
+            item_id: None,
+        }
+    }
+
+    fn turn(thread_id: &'a str, turn_id: &'a str) -> Self {
+        Self {
+            event_name: "turn",
+            thread_id,
+            turn_id: Some(turn_id),
+            review_id: None,
+            item_id: None,
+        }
+    }
+}
+
+enum MissingAnalyticsContext {
+    ThreadConnection,
+    Connection { connection_id: u64 },
+    ThreadMetadata,
+}
+
 #[derive(Clone)]
 struct ThreadMetadataState {
     thread_source: Option<&'static str>,
@@ -271,6 +348,22 @@ impl AnalyticsReducer {
         input: SubAgentThreadStartedInput,
         out: &mut Vec<TrackEventRequest>,
     ) {
+        let parent_thread_id = input
+            .parent_thread_id
+            .clone()
+            .or_else(|| subagent_parent_thread_id(&input.subagent_source));
+        let parent_connection_id = parent_thread_id
+            .as_ref()
+            .and_then(|parent_thread_id| self.threads.get(parent_thread_id))
+            .and_then(|thread| thread.connection_id);
+        let thread_state = self.threads.entry(input.thread_id.clone()).or_default();
+        thread_state.metadata = Some(ThreadMetadataState {
+            thread_source: Some("subagent"),
+            initialization_mode: ThreadInitializationMode::New,
+            subagent_source: Some(subagent_source_name(&input.subagent_source)),
+            parent_thread_id,
+        });
+        thread_state.connection_id = parent_connection_id;
         out.push(TrackEventRequest::ThreadInitialized(
             subagent_thread_started_event_request(input),
         ));
@@ -281,23 +374,15 @@ impl AnalyticsReducer {
         input: GuardianReviewEventParams,
         out: &mut Vec<TrackEventRequest>,
     ) {
-        let Some(connection_id) = self.thread_connections.get(&input.thread_id) else {
-            tracing::warn!(
-                thread_id = %input.thread_id,
-                turn_id = %input.turn_id,
-                review_id = %input.review_id,
-                "dropping guardian analytics event: missing thread connection metadata"
-            );
-            return;
-        };
-        let Some(connection_state) = self.connections.get(connection_id) else {
-            tracing::warn!(
-                thread_id = %input.thread_id,
-                turn_id = %input.turn_id,
-                review_id = %input.review_id,
-                connection_id,
-                "dropping guardian analytics event: missing connection metadata"
-            );
+        let Some(ResolvedAnalyticsContext {
+            connection_state,
+            thread_metadata: None,
+        }) = self.resolve_analytics_context(
+            AnalyticsDropSite::guardian(&input),
+            AnalyticsConnectionSource::Thread(&input.thread_id),
+            ThreadMetadataRequirement::NotRequired,
+        )
+        else {
             return;
         };
         out.push(TrackEventRequest::GuardianReview(Box::new(
@@ -683,10 +768,13 @@ impl AnalyticsReducer {
         };
         let thread_metadata =
             ThreadMetadataState::from_thread_metadata(&thread_source, initialization_mode);
-        self.thread_connections
-            .insert(thread_id.clone(), connection_id);
-        self.thread_metadata
-            .insert(thread_id.clone(), thread_metadata.clone());
+        self.threads.insert(
+            thread_id.clone(),
+            ThreadAnalyticsState {
+                connection_id: Some(connection_id),
+                metadata: Some(thread_metadata.clone()),
+            },
+        );
         out.push(TrackEventRequest::ThreadInitialized(
             ThreadInitializedEvent {
                 event_type: "codex_thread_initialized",
@@ -707,29 +795,15 @@ impl AnalyticsReducer {
     }
 
     fn ingest_compaction(&mut self, input: CodexCompactionEvent, out: &mut Vec<TrackEventRequest>) {
-        let Some(connection_id) = self.thread_connections.get(&input.thread_id) else {
-            tracing::warn!(
-                thread_id = %input.thread_id,
-                turn_id = %input.turn_id,
-                "dropping compaction analytics event: missing thread connection metadata"
-            );
-            return;
-        };
-        let Some(connection_state) = self.connections.get(connection_id) else {
-            tracing::warn!(
-                thread_id = %input.thread_id,
-                turn_id = %input.turn_id,
-                connection_id,
-                "dropping compaction analytics event: missing connection metadata"
-            );
-            return;
-        };
-        let Some(thread_metadata) = self.thread_metadata.get(&input.thread_id) else {
-            tracing::warn!(
-                thread_id = %input.thread_id,
-                turn_id = %input.turn_id,
-                "dropping compaction analytics event: missing thread lifecycle metadata"
-            );
+        let Some(ResolvedAnalyticsContext {
+            connection_state,
+            thread_metadata: Some(thread_metadata),
+        }) = self.resolve_analytics_context(
+            AnalyticsDropSite::compaction(&input),
+            AnalyticsConnectionSource::Thread(&input.thread_id),
+            ThreadMetadataRequirement::Required(&input.thread_id),
+        )
+        else {
             return;
         };
         out.push(TrackEventRequest::Compaction(Box::new(
@@ -781,14 +855,15 @@ impl AnalyticsReducer {
         rejection_reason: Option<TurnSteerRejectionReason>,
         out: &mut Vec<TrackEventRequest>,
     ) {
-        let Some(connection_state) = self.connections.get(&connection_id) else {
-            return;
-        };
-        let Some(thread_metadata) = self.thread_metadata.get(&pending_request.thread_id) else {
-            tracing::warn!(
-                thread_id = %pending_request.thread_id,
-                "dropping turn steer analytics event: missing thread lifecycle metadata"
-            );
+        let Some(ResolvedAnalyticsContext {
+            connection_state,
+            thread_metadata: Some(thread_metadata),
+        }) = self.resolve_analytics_context(
+            AnalyticsDropSite::turn_steer(&pending_request.thread_id),
+            AnalyticsConnectionSource::Known(connection_id),
+            ThreadMetadataRequirement::Required(&pending_request.thread_id),
+        )
+        else {
             return;
         };
         out.push(TrackEventRequest::TurnSteer(CodexTurnSteerEventRequest {
@@ -821,42 +896,26 @@ impl AnalyticsReducer {
         {
             return;
         }
-        let connection_metadata = turn_state
-            .connection_id
-            .and_then(|connection_id| self.connections.get(&connection_id))
-            .map(|connection_state| {
-                (
-                    connection_state.app_server_client.clone(),
-                    connection_state.runtime.clone(),
-                )
-            });
-        let Some((app_server_client, runtime)) = connection_metadata else {
-            if let Some(connection_id) = turn_state.connection_id {
-                tracing::warn!(
-                    turn_id,
-                    connection_id,
-                    "dropping turn analytics event: missing connection metadata"
-                );
-            }
-            return;
-        };
         let Some(thread_id) = turn_state.thread_id.as_ref() else {
             return;
         };
-        let Some(thread_metadata) = self.thread_metadata.get(thread_id) else {
-            tracing::warn!(
-                thread_id,
-                turn_id,
-                "dropping turn analytics event: missing thread lifecycle metadata"
-            );
+        let Some(ResolvedAnalyticsContext {
+            connection_state,
+            thread_metadata: Some(thread_metadata),
+        }) = self.resolve_analytics_context(
+            AnalyticsDropSite::turn(thread_id, turn_id),
+            AnalyticsConnectionSource::MaybeKnown(turn_state.connection_id),
+            ThreadMetadataRequirement::Required(thread_id),
+        )
+        else {
             return;
         };
         out.push(TrackEventRequest::TurnEvent(Box::new(
             CodexTurnEventRequest {
                 event_type: "codex_turn_event",
                 event_params: codex_turn_event_params(
-                    app_server_client,
-                    runtime,
+                    connection_state.app_server_client.clone(),
+                    connection_state.runtime.clone(),
                     turn_id.to_string(),
                     turn_state,
                     thread_metadata,
@@ -865,6 +924,105 @@ impl AnalyticsReducer {
         )));
         self.turns.remove(turn_id);
     }
+
+    fn resolve_analytics_context(
+        &self,
+        drop_site: AnalyticsDropSite<'_>,
+        connection_source: AnalyticsConnectionSource<'_>,
+        thread_metadata_requirement: ThreadMetadataRequirement<'_>,
+    ) -> Option<ResolvedAnalyticsContext<'_>> {
+        let connection_id = match connection_source {
+            AnalyticsConnectionSource::Thread(thread_id) => {
+                let Some(thread_state) = self.threads.get(thread_id) else {
+                    warn_missing_analytics_context(
+                        &drop_site,
+                        MissingAnalyticsContext::ThreadConnection,
+                    );
+                    return None;
+                };
+                let Some(connection_id) = thread_state.connection_id else {
+                    warn_missing_analytics_context(
+                        &drop_site,
+                        MissingAnalyticsContext::ThreadConnection,
+                    );
+                    return None;
+                };
+                connection_id
+            }
+            AnalyticsConnectionSource::Known(connection_id) => connection_id,
+            AnalyticsConnectionSource::MaybeKnown(None) => return None,
+            AnalyticsConnectionSource::MaybeKnown(Some(connection_id)) => connection_id,
+        };
+        let Some(connection_state) = self.connections.get(&connection_id) else {
+            warn_missing_analytics_context(
+                &drop_site,
+                MissingAnalyticsContext::Connection { connection_id },
+            );
+            return None;
+        };
+        let thread_metadata = match thread_metadata_requirement {
+            ThreadMetadataRequirement::NotRequired => None,
+            ThreadMetadataRequirement::Required(thread_id) => {
+                let Some(thread_metadata) = self.thread_metadata(thread_id) else {
+                    warn_missing_analytics_context(
+                        &drop_site,
+                        MissingAnalyticsContext::ThreadMetadata,
+                    );
+                    return None;
+                };
+                Some(thread_metadata)
+            }
+        };
+        Some(ResolvedAnalyticsContext {
+            connection_state,
+            thread_metadata,
+        })
+    }
+
+    fn thread_metadata(&self, thread_id: &str) -> Option<&ThreadMetadataState> {
+        self.threads
+            .get(thread_id)
+            .and_then(|thread| thread.metadata.as_ref())
+    }
+}
+
+fn warn_missing_analytics_context(
+    drop_site: &AnalyticsDropSite<'_>,
+    missing: MissingAnalyticsContext,
+) {
+    match missing {
+        MissingAnalyticsContext::ThreadConnection => {
+            tracing::warn!(
+                thread_id = %drop_site.thread_id,
+                turn_id = ?drop_site.turn_id,
+                review_id = ?drop_site.review_id,
+                item_id = ?drop_site.item_id,
+                "dropping {} analytics event: missing thread connection metadata",
+                drop_site.event_name
+            );
+        }
+        MissingAnalyticsContext::Connection { connection_id } => {
+            tracing::warn!(
+                thread_id = %drop_site.thread_id,
+                turn_id = ?drop_site.turn_id,
+                review_id = ?drop_site.review_id,
+                item_id = ?drop_site.item_id,
+                connection_id,
+                "dropping {} analytics event: missing connection metadata",
+                drop_site.event_name
+            );
+        }
+        MissingAnalyticsContext::ThreadMetadata => {
+            tracing::warn!(
+                thread_id = %drop_site.thread_id,
+                turn_id = ?drop_site.turn_id,
+                review_id = ?drop_site.review_id,
+                item_id = ?drop_site.item_id,
+                "dropping {} analytics event: missing thread lifecycle metadata",
+                drop_site.event_name
+            );
+        }
+    }
 }
 
 fn codex_turn_event_params(