diff --git a/codex-rs/analytics/src/analytics_client.rs b/codex-rs/analytics/src/analytics_client.rs
index 2dcd27a25a..646b4fc6ac 100644
--- a/codex-rs/analytics/src/analytics_client.rs
+++ b/codex-rs/analytics/src/analytics_client.rs
@@ -735,6 +735,7 @@ fn personality_mode(personality: Option<Personality>) -> Option<String> {
         Some(personality) => Some(personality.to_string()),
     }
 }
+
 fn codex_thread_initialized_event_params(
     thread_event: CodexThreadInitializedEvent,
 ) -> CodexThreadInitializedEventParams {
diff --git a/codex-rs/analytics/src/analytics_client_tests.rs b/codex-rs/analytics/src/analytics_client_tests.rs
index 425e7818e0..8d59236c31 100644
--- a/codex-rs/analytics/src/analytics_client_tests.rs
+++ b/codex-rs/analytics/src/analytics_client_tests.rs
@@ -5,7 +5,6 @@ use super::CodexAppUsedEventRequest;
 use super::CodexPluginEventRequest;
 use super::CodexPluginUsedEventRequest;
 use super::CodexThreadInitializedEvent;
-use super::CodexThreadInitializedEventRequest;
 use super::CodexTurnEvent;
 use super::CodexTurnEventRequest;
 use super::InitializationMode;
@@ -16,7 +15,7 @@ use super::TrackEventsContext;
 use super::codex_app_metadata;
 use super::codex_plugin_metadata;
 use super::codex_plugin_used_metadata;
-use super::codex_thread_initialized_event_params;
+use super::codex_thread_initialized_event_request;
 use super::codex_turn_event_params;
 use super::normalize_path_for_skill_id;
 use codex_login::default_client::originator;
@@ -264,9 +263,8 @@ fn turn_event_serializes_expected_shape() {
 
 #[test]
 fn thread_initialized_event_serializes_expected_shape() {
-    let event = TrackEventRequest::ThreadInitialized(CodexThreadInitializedEventRequest {
-        event_type: "codex_thread_initialized",
-        event_params: codex_thread_initialized_event_params(CodexThreadInitializedEvent {
+    let event = TrackEventRequest::ThreadInitialized(codex_thread_initialized_event_request(
+        CodexThreadInitializedEvent {
             thread_id: "thread-0".to_string(),
             model: "gpt-5".to_string(),
             ephemeral: true,
@@ -275,8 +273,8 @@ fn thread_initialized_event_serializes_expected_shape() {
             subagent_source: None,
             parent_thread_id: None,
             created_at: 1_716_000_000,
-        }),
-    });
+        },
+    ));
 
     let payload = serde_json::to_value(&event).expect("serialize thread initialized event");
 
@@ -301,9 +299,8 @@ fn thread_initialized_event_serializes_expected_shape() {
 
 #[test]
 fn thread_initialized_event_serializes_subagent_source() {
-    let event = TrackEventRequest::ThreadInitialized(CodexThreadInitializedEventRequest {
-        event_type: "codex_thread_initialized",
-        event_params: codex_thread_initialized_event_params(CodexThreadInitializedEvent {
+    let event = TrackEventRequest::ThreadInitialized(codex_thread_initialized_event_request(
+        CodexThreadInitializedEvent {
             thread_id: "thread-1".to_string(),
             model: "gpt-5".to_string(),
             ephemeral: false,
@@ -312,8 +309,8 @@ fn thread_initialized_event_serializes_subagent_source() {
             subagent_source: Some(SubAgentSource::Review),
             parent_thread_id: None,
             created_at: 1,
-        }),
-    });
+        },
+    ));
 
     let payload =
         serde_json::to_value(&event).expect("serialize subagent thread initialized event");
@@ -323,9 +320,8 @@ fn thread_initialized_event_serializes_subagent_source() {
 
 #[test]
 fn thread_initialized_event_omits_non_user_non_subagent_session_source() {
-    let event = TrackEventRequest::ThreadInitialized(CodexThreadInitializedEventRequest {
-        event_type: "codex_thread_initialized",
-        event_params: codex_thread_initialized_event_params(CodexThreadInitializedEvent {
+    let event = TrackEventRequest::ThreadInitialized(codex_thread_initialized_event_request(
+        CodexThreadInitializedEvent {
             thread_id: "thread-2".to_string(),
             model: "gpt-5".to_string(),
             ephemeral: false,
@@ -334,8 +330,8 @@ fn thread_initialized_event_omits_non_user_non_subagent_session_source() {
             subagent_source: None,
             parent_thread_id: None,
             created_at: 1,
-        }),
-    });
+        },
+    ));
 
     let payload = serde_json::to_value(&event).expect("serialize mcp thread initialized event");
     assert_eq!(
diff --git a/codex-rs/core/src/codex.rs b/codex-rs/core/src/codex.rs
index ba6fee03d4..75a517a57a 100644
--- a/codex-rs/core/src/codex.rs
+++ b/codex-rs/core/src/codex.rs
@@ -642,6 +642,8 @@ impl Codex {
 
         let initialization_mode = initialization_mode(&conversation_history);
         let thread_session_source = session_configuration.session_source.clone();
+        let subagent_source = session_source_subagent_source(&thread_session_source);
+        let parent_thread_id = session_source_parent_thread_id(&thread_session_source);
         let thread_initialized_configuration = session_configuration.clone();
 
         // Generate a unique ID for the lifetime of this Codex session.
@@ -691,8 +693,8 @@ impl Codex {
                         .ephemeral,
                     session_source: thread_session_source,
                     initialization_mode,
-                    subagent_source: session_source_subagent_source(&thread_session_source),
-                    parent_thread_id: session_source_parent_thread_id(&thread_session_source),
+                    subagent_source,
+                    parent_thread_id,
                 },
             });