diff --git a/codex-rs/analytics/src/analytics_client_tests.rs b/codex-rs/analytics/src/analytics_client_tests.rs
index 1acfdb92d3..a89e684aa2 100644
--- a/codex-rs/analytics/src/analytics_client_tests.rs
+++ b/codex-rs/analytics/src/analytics_client_tests.rs
@@ -287,7 +287,6 @@ fn sample_turn_resolved_config(turn_id: &str) -> TurnResolvedConfigFact {
         submission_type: None,
         ephemeral: false,
         session_source: SessionSource::Exec,
-        initialization_mode: ThreadInitializationMode::New,
         model: "gpt-5".to_string(),
         model_provider: "openai".to_string(),
         sandbox_policy: SandboxPolicy::new_read_only_policy(),
@@ -456,6 +455,18 @@ async fn ingest_turn_prerequisites(
 ) {
     if include_initialize {
         ingest_initialize(reducer, out).await;
+        reducer
+            .ingest(
+                AnalyticsFact::Response {
+                    connection_id: 7,
+                    response: Box::new(sample_thread_start_response(
+                        "thread-2", /*ephemeral*/ false, "gpt-5",
+                    )),
+                },
+                out,
+            )
+            .await;
+        out.clear();
     }
 
     reducer
@@ -1611,6 +1622,10 @@ async fn accepted_turn_steer_emits_expected_event() {
         payload["event_params"]["runtime"]["codex_rs_version"],
         json!("0.1.0")
     );
+    assert_eq!(payload["event_params"]["thread_source"], json!("user"));
+    assert_eq!(payload["event_params"]["initialization_mode"], json!("new"));
+    assert_eq!(payload["event_params"]["subagent_source"], json!(null));
+    assert_eq!(payload["event_params"]["parent_thread_id"], json!(null));
     assert!(payload["event_params"].get("product_client_id").is_none());
 }
 
@@ -1639,6 +1654,10 @@ async fn rejected_turn_steer_uses_request_connection_metadata() {
         payload["event_params"]["runtime"]["codex_rs_version"],
         json!("0.1.0")
     );
+    assert_eq!(payload["event_params"]["thread_source"], json!("user"));
+    assert_eq!(payload["event_params"]["initialization_mode"], json!("new"));
+    assert_eq!(payload["event_params"]["subagent_source"], json!(null));
+    assert_eq!(payload["event_params"]["parent_thread_id"], json!(null));
     assert_eq!(payload["event_params"]["result"], json!("rejected"));
     assert_eq!(
         payload["event_params"]["rejection_reason"],
diff --git a/codex-rs/analytics/src/events.rs b/codex-rs/analytics/src/events.rs
index 4bc3ccde9d..74105a742d 100644
--- a/codex-rs/analytics/src/events.rs
+++ b/codex-rs/analytics/src/events.rs
@@ -213,6 +213,10 @@ pub(crate) struct CodexTurnSteerEventParams {
     pub(crate) accepted_turn_id: Option<String>,
     pub(crate) app_server_client: CodexAppServerClientMetadata,
     pub(crate) runtime: CodexRuntimeMetadata,
+    pub(crate) thread_source: Option<String>,
+    pub(crate) initialization_mode: ThreadInitializationMode,
+    pub(crate) subagent_source: Option<String>,
+    pub(crate) parent_thread_id: Option<String>,
     pub(crate) num_input_images: usize,
     pub(crate) result: TurnSteerResult,
     pub(crate) rejection_reason: Option<TurnSteerRejectionReason>,
@@ -351,6 +355,10 @@ pub(crate) fn codex_turn_steer_event_params(
     app_server_client: CodexAppServerClientMetadata,
     runtime: CodexRuntimeMetadata,
     tracking: &TrackEventsContext,
+    thread_source: Option<&'static str>,
+    initialization_mode: ThreadInitializationMode,
+    subagent_source: Option<String>,
+    parent_thread_id: Option<String>,
     turn_steer: CodexTurnSteerEvent,
 ) -> CodexTurnSteerEventParams {
     CodexTurnSteerEventParams {
@@ -359,6 +367,10 @@ pub(crate) fn codex_turn_steer_event_params(
         accepted_turn_id: turn_steer.accepted_turn_id,
         app_server_client,
         runtime,
+        thread_source: thread_source.map(str::to_string),
+        initialization_mode,
+        subagent_source,
+        parent_thread_id,
         num_input_images: turn_steer.num_input_images,
         result: turn_steer.result,
         rejection_reason: turn_steer.rejection_reason,
diff --git a/codex-rs/analytics/src/facts.rs b/codex-rs/analytics/src/facts.rs
index 446186507a..b7f34ba803 100644
--- a/codex-rs/analytics/src/facts.rs
+++ b/codex-rs/analytics/src/facts.rs
@@ -56,7 +56,6 @@ pub struct TurnResolvedConfigFact {
     pub submission_type: Option<TurnSubmissionType>,
     pub ephemeral: bool,
     pub session_source: SessionSource,
-    pub initialization_mode: ThreadInitializationMode,
     pub model: String,
     pub model_provider: String,
     pub sandbox_policy: SandboxPolicy,
diff --git a/codex-rs/analytics/src/reducer.rs b/codex-rs/analytics/src/reducer.rs
index 6edcbb0ccb..00e4b7abd7 100644
--- a/codex-rs/analytics/src/reducer.rs
+++ b/codex-rs/analytics/src/reducer.rs
@@ -83,12 +83,16 @@ struct ConnectionState {
 #[derive(Clone)]
 struct ThreadMetadataState {
     thread_source: Option<&'static str>,
+    initialization_mode: ThreadInitializationMode,
     subagent_source: Option<String>,
     parent_thread_id: Option<String>,
 }
 
 impl ThreadMetadataState {
-    fn from_session_source(session_source: &SessionSource) -> Self {
+    fn from_thread_lifecycle(
+        session_source: &SessionSource,
+        initialization_mode: ThreadInitializationMode,
+    ) -> Self {
         let (subagent_source, parent_thread_id) = match session_source {
             SessionSource::SubAgent(subagent_source) => (
                 Some(subagent_source_name(subagent_source)),
@@ -103,6 +107,7 @@ impl ThreadMetadataState {
         };
         Self {
             thread_source: thread_source_name(session_source),
+            initialization_mode,
             subagent_source,
             parent_thread_id,
         }
@@ -615,7 +620,8 @@ impl AnalyticsReducer {
         let Some(connection_state) = self.connections.get(&connection_id) else {
             return;
         };
-        let thread_metadata = ThreadMetadataState::from_session_source(&thread_source);
+        let thread_metadata =
+            ThreadMetadataState::from_thread_lifecycle(&thread_source, initialization_mode);
         self.thread_connections
             .insert(thread_id.clone(), connection_id);
         self.thread_metadata
@@ -717,6 +723,13 @@ impl AnalyticsReducer {
         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"
+            );
+            return;
+        };
         let tracking = TrackEventsContext {
             model_slug: String::new(),
             thread_id: pending_request.thread_id,
@@ -739,6 +752,10 @@ impl AnalyticsReducer {
                 connection_state.app_server_client.clone(),
                 connection_state.runtime.clone(),
                 &tracking,
+                thread_metadata.thread_source,
+                thread_metadata.initialization_mode,
+                thread_metadata.subagent_source.clone(),
+                thread_metadata.parent_thread_id.clone(),
                 turn_steer,
             ),
         }));
@@ -765,6 +782,24 @@ impl AnalyticsReducer {
                 )
             });
         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"
+            );
             return;
         };
         out.push(TrackEventRequest::TurnEvent(Box::new(
@@ -775,6 +810,7 @@ impl AnalyticsReducer {
                     runtime,
                     turn_id.to_string(),
                     turn_state,
+                    thread_metadata,
                 ),
             },
         )));
@@ -787,6 +823,7 @@ fn codex_turn_event_params(
     runtime: CodexRuntimeMetadata,
     turn_id: String,
     turn_state: &TurnState,
+    thread_metadata: &ThreadMetadataState,
 ) -> CodexTurnEventParams {
     let (Some(thread_id), Some(num_input_images), Some(resolved_config), Some(completed)) = (
         turn_state.thread_id.clone(),
@@ -803,8 +840,7 @@ fn codex_turn_event_params(
         num_input_images: _resolved_num_input_images,
         submission_type,
         ephemeral,
-        session_source,
-        initialization_mode,
+        session_source: _session_source,
         model,
         model_provider,
         sandbox_policy,
@@ -826,10 +862,10 @@ fn codex_turn_event_params(
         runtime,
         submission_type,
         ephemeral,
-        thread_source: thread_source_name(&session_source).map(str::to_string),
-        initialization_mode,
-        subagent_source: None,
-        parent_thread_id: None,
+        thread_source: thread_metadata.thread_source.map(str::to_string),
+        initialization_mode: thread_metadata.initialization_mode,
+        subagent_source: thread_metadata.subagent_source.clone(),
+        parent_thread_id: thread_metadata.parent_thread_id.clone(),
         model: Some(model),
         model_provider,
         sandbox_policy: Some(sandbox_policy_mode(&sandbox_policy)),
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 ea3ba02b46..694d0a6eef 100644
--- a/codex-rs/app-server/tests/suite/v2/turn_start.rs
+++ b/codex-rs/app-server/tests/suite/v2/turn_start.rs
@@ -395,6 +395,17 @@ async fn turn_start_tracks_turn_event_analytics() -> Result<()> {
     assert_eq!(event["event_params"]["model"], "mock-model");
     assert_eq!(event["event_params"]["model_provider"], "mock_provider");
     assert_eq!(event["event_params"]["sandbox_policy"], "read_only");
+    assert_eq!(event["event_params"]["ephemeral"], false);
+    assert_eq!(event["event_params"]["thread_source"], "user");
+    assert_eq!(event["event_params"]["initialization_mode"], "new");
+    assert_eq!(
+        event["event_params"]["subagent_source"],
+        serde_json::Value::Null
+    );
+    assert_eq!(
+        event["event_params"]["parent_thread_id"],
+        serde_json::Value::Null
+    );
     assert_eq!(event["event_params"]["num_input_images"], 1);
     assert_eq!(event["event_params"]["status"], "completed");
     assert!(event["event_params"]["started_at"].as_u64().is_some());
diff --git a/codex-rs/core/src/codex.rs b/codex-rs/core/src/codex.rs
index ad171ef98f..49588490ae 100644
--- a/codex-rs/core/src/codex.rs
+++ b/codex-rs/core/src/codex.rs
@@ -55,7 +55,6 @@ use codex_analytics::CompactionPhase;
 use codex_analytics::CompactionReason;
 use codex_analytics::InvocationType;
 use codex_analytics::SubAgentThreadStartedInput;
-use codex_analytics::ThreadInitializationMode;
 use codex_analytics::TurnResolvedConfigFact;
 use codex_analytics::build_track_events_context;
 use codex_app_server_protocol::AuthMode;
@@ -657,7 +656,6 @@ impl Codex {
             app_server_client_name: None,
             app_server_client_version: None,
             session_source,
-            thread_initialization_mode: ThreadInitializationMode::New,
             dynamic_tools,
             persist_extended_history,
             inherited_shell_snapshot,
@@ -1175,7 +1173,6 @@ pub(crate) struct SessionConfiguration {
     app_server_client_version: Option<String>,
     /// Source of the session (cli, vscode, exec, mcp, ...)
     session_source: SessionSource,
-    thread_initialization_mode: ThreadInitializationMode,
     dynamic_tools: Vec<DynamicToolSpec>,
     persist_extended_history: bool,
     inherited_shell_snapshot: Option<Arc<ShellSnapshot>>,
@@ -1200,7 +1197,6 @@ impl SessionConfiguration {
             reasoning_effort: self.collaboration_mode.reasoning_effort(),
             personality: self.personality,
             session_source: self.session_source.clone(),
-            initialization_mode: self.thread_initialization_mode,
         }
     }
 
@@ -6534,7 +6530,6 @@ async fn track_turn_resolved_config_analytics(
             submission_type: None,
             ephemeral: thread_config.ephemeral,
             session_source: thread_config.session_source,
-            initialization_mode: thread_config.initialization_mode,
             model: turn_context.model_info.slug.clone(),
             model_provider: turn_context.config.model_provider_id.clone(),
             sandbox_policy: turn_context.sandbox_policy.get().clone(),
diff --git a/codex-rs/core/src/codex_tests.rs b/codex-rs/core/src/codex_tests.rs
index ae444b4975..6e901a0346 100644
--- a/codex-rs/core/src/codex_tests.rs
+++ b/codex-rs/core/src/codex_tests.rs
@@ -15,8 +15,6 @@ use crate::mcp_tool_exposure::build_mcp_tool_exposure;
 use crate::shell::default_user_shell;
 use crate::tools::format_exec_output_str;
 
-use codex_analytics::ThreadInitializationMode;
-
 use codex_features::Features;
 use codex_login::CodexAuth;
 use codex_mcp::CODEX_APPS_MCP_SERVER_NAME;
@@ -1993,7 +1991,6 @@ async fn set_rate_limits_retains_previous_credits() {
         app_server_client_name: None,
         app_server_client_version: None,
         session_source: SessionSource::Exec,
-        thread_initialization_mode: ThreadInitializationMode::New,
         dynamic_tools: Vec::new(),
         persist_extended_history: false,
         inherited_shell_snapshot: None,
@@ -2096,7 +2093,6 @@ async fn set_rate_limits_updates_plan_type_when_present() {
         app_server_client_name: None,
         app_server_client_version: None,
         session_source: SessionSource::Exec,
-        thread_initialization_mode: ThreadInitializationMode::New,
         dynamic_tools: Vec::new(),
         persist_extended_history: false,
         inherited_shell_snapshot: None,
@@ -2449,7 +2445,6 @@ pub(crate) async fn make_session_configuration_for_tests() -> SessionConfigurati
         app_server_client_name: None,
         app_server_client_version: None,
         session_source: SessionSource::Exec,
-        thread_initialization_mode: ThreadInitializationMode::New,
         dynamic_tools: Vec::new(),
         persist_extended_history: false,
         inherited_shell_snapshot: None,
@@ -2713,7 +2708,6 @@ async fn session_new_fails_when_zsh_fork_enabled_without_zsh_path() {
         app_server_client_name: None,
         app_server_client_version: None,
         session_source: SessionSource::Exec,
-        thread_initialization_mode: ThreadInitializationMode::New,
         dynamic_tools: Vec::new(),
         persist_extended_history: false,
         inherited_shell_snapshot: None,
@@ -2818,7 +2812,6 @@ pub(crate) async fn make_session_and_context() -> (Session, TurnContext) {
         app_server_client_name: None,
         app_server_client_version: None,
         session_source: SessionSource::Exec,
-        thread_initialization_mode: ThreadInitializationMode::New,
         dynamic_tools: Vec::new(),
         persist_extended_history: false,
         inherited_shell_snapshot: None,
@@ -3664,7 +3657,6 @@ pub(crate) async fn make_session_and_context_with_dynamic_tools_and_rx(
         app_server_client_name: None,
         app_server_client_version: None,
         session_source: SessionSource::Exec,
-        thread_initialization_mode: ThreadInitializationMode::New,
         dynamic_tools,
         persist_extended_history: false,
         inherited_shell_snapshot: None,
diff --git a/codex-rs/core/src/codex_thread.rs b/codex-rs/core/src/codex_thread.rs
index f7b2904659..e90dd0f80a 100644
--- a/codex-rs/core/src/codex_thread.rs
+++ b/codex-rs/core/src/codex_thread.rs
@@ -3,7 +3,6 @@ use crate::codex::Codex;
 use crate::codex::SteerInputError;
 use crate::config::ConstraintResult;
 use crate::file_watcher::WatchRegistration;
-use codex_analytics::ThreadInitializationMode;
 use codex_features::Feature;
 use codex_protocol::config_types::ApprovalsReviewer;
 use codex_protocol::config_types::Personality;
@@ -44,7 +43,6 @@ pub struct ThreadConfigSnapshot {
     pub reasoning_effort: Option<ReasoningEffort>,
     pub personality: Option<Personality>,
     pub session_source: SessionSource,
-    pub initialization_mode: ThreadInitializationMode,
 }
 
 pub struct CodexThread {