Replace Guardian tickets with parent response IDs (#43002)

## What changed

Capture the ID from `response.created` and pass it as `parent_response_id` in Guardian review and classifier request metadata. Clear the current response ID before sampling retries so tool reviews cannot inherit a failed response's ID.

Request Guardian credits with `guardian_credits_requested` on eligible parent requests. Remove the ticket protocol, transport attachment, and ticket-specific body redaction. Keep ordinary app-server client `parent_response_id` values inside `x-codex-turn-metadata` rather than promoting them to Guardian request metadata.

## Testing

Update coverage for HTTP fallback, WebSocket review reuse, missing response IDs, classifier transport retries, and code-mode yield/resume attribution. Extend app-server tests to verify client metadata placement over HTTP and WebSocket.

GitOrigin-RevId: c1665e56382ecec8d260fc2ca0ecd5e20b0b2391

codex-rs/core/src/client.rs

@@ -1104,14 +1104,24 @@ impl ModelClient {
             && provider.aws.is_none()
     }
 
-    fn set_guardian_ticket_request(
+    fn set_guardian_metadata(
         &self,
         metadata: &mut Option<HashMap<String, String>>,
+        parent_response_id: Option<&str>,
         auth: Option<&CodexAuth>,
         endpoint: ResponsesEndpoint,
     ) {
         if let Some(metadata) = metadata.as_mut() {
-            metadata.remove("guardian_ticket_requested");
+            metadata.remove("guardian_credits_requested");
+            metadata.remove("parent_response_id");
+        }
+        if endpoint == ResponsesEndpoint::Guardian
+            && let Some(parent_response_id) = parent_response_id
+        {
+            metadata.get_or_insert_with(HashMap::new).insert(
+                "parent_response_id".to_owned(),
+                parent_response_id.to_owned(),
+            );
         }
         if self.free_guardian_enabled
             && endpoint == ResponsesEndpoint::Responses
@@ -1125,7 +1135,7 @@ impl ModelClient {
         {
             metadata
                 .get_or_insert_with(HashMap::new)
-                .insert("guardian_ticket_requested".to_owned(), "true".to_owned());
+                .insert("guardian_credits_requested".to_owned(), "true".to_owned());
         }
     }
 
@@ -1351,7 +1361,6 @@ impl ModelClientSession {
             },
             compression,
             turn_state: Some(Arc::clone(&self.turn_state)),
-            guardian_ticket: responses_metadata.guardian_ticket.clone(),
         }
     }
 
@@ -1641,8 +1650,9 @@ impl ModelClientSession {
                 service_tier.clone(),
                 responses_metadata,
             )?;
-            self.client.set_guardian_ticket_request(
+            self.client.set_guardian_metadata(
                 &mut request.client_metadata,
+                responses_metadata.parent_response_id.as_deref(),
                 client_setup.auth.as_ref(),
                 endpoint,
             );
@@ -1900,8 +1910,9 @@ impl ModelClientSession {
                 ),
                 ..ResponseCreateWsRequest::from(&request)
             };
-            self.client.set_guardian_ticket_request(
+            self.client.set_guardian_metadata(
                 &mut ws_payload.client_metadata,
+                responses_metadata.parent_response_id.as_deref(),
                 client_setup.auth.as_ref(),
                 endpoint,
             );
@@ -1922,7 +1933,6 @@ impl ModelClientSession {
                     ws_request,
                     self.websocket_session.connection_reused(),
                     Some(Arc::clone(&self.turn_state)),
-                    responses_metadata.guardian_ticket.as_ref(),
                 )
                 .await;
             if let Some(original_item_ids) = original_item_ids {

codex-rs/core/src/client_tests.rs

@@ -844,9 +844,7 @@ async fn response_stream_records_last_model_feedback_ids() {
         .set_default();
 
     let api_stream = futures::stream::iter([
-        Ok(ResponseEvent::Created {
-            guardian_ticket: None,
-        }),
+        Ok(ResponseEvent::Created { response_id: None }),
         Ok(ResponseEvent::Completed {
             response_id: "resp-123".to_string(),
             token_usage: None,
@@ -1062,9 +1060,7 @@ async fn dropped_backpressured_response_stream_traces_cancelled_partial_output()
     let backpressured_item_yielded = Arc::new(Notify::new());
     let mut events = VecDeque::new();
     for _ in 0..super::RESPONSE_STREAM_CHANNEL_CAPACITY {
-        events.push_back(ResponseEvent::Created {
-            guardian_ticket: None,
-        });
+        events.push_back(ResponseEvent::Created { response_id: None });
     }
     events.push_back(ResponseEvent::OutputItemDone(output_message(
         "1",

codex-rs/core/src/guardian/mod.rs

@@ -88,8 +88,8 @@ const GUARDIAN_RECENT_ENTRY_LIMIT: usize = 40;
 /// step-scoped things past their lifetime (like MCP bindings)
 #[derive(Clone)]
 pub(crate) struct GuardianReviewContext {
-    /// Ticket from the response currently handled in this execution context.
-    pub(crate) guardian_ticket: Option<codex_protocol::guardian_ticket::GuardianTicket>,
+    /// The response currently handled in this execution context.
+    pub(crate) parent_response_id: Option<String>,
     turn: Arc<TurnContext>,
     environments: TurnEnvironmentSnapshot,
     // Model and reasoning inputs are carried for the follow-up Guardian and V2 migrations.
@@ -109,11 +109,10 @@ impl GuardianReviewContext {
         settings: &ResolvedStepSettings,
     ) -> Self {
         Self {
-            guardian_ticket: turn
+            parent_response_id: turn
                 .extension_data
-                .get::<codex_protocol::guardian_ticket::GuardianTicket>()
-                .as_deref()
-                .cloned(),
+                .get::<codex_api::ResponseId>()
+                .map(|id| id.0.clone()),
             environments: turn.environments.clone(),
             model_info: Arc::clone(&settings.model_info),
             reasoning_effort: settings.reasoning_effort().cloned(),
@@ -136,12 +135,11 @@ impl GuardianReviewContext {
 impl From<&Arc<StepContext>> for GuardianReviewContext {
     fn from(step: &Arc<StepContext>) -> Self {
         Self {
-            guardian_ticket: step
+            parent_response_id: step
                 .turn
                 .extension_data
-                .get::<codex_protocol::guardian_ticket::GuardianTicket>()
-                .as_deref()
-                .cloned(),
+                .get::<codex_api::ResponseId>()
+                .map(|id| id.0.clone()),
             turn: Arc::clone(&step.turn),
             environments: step.environments.clone(),
             model_info: Arc::clone(&step.settings.model_info),
@@ -156,11 +154,10 @@ impl From<&Arc<StepContext>> for GuardianReviewContext {
 impl From<Arc<TurnContext>> for GuardianReviewContext {
     fn from(turn: Arc<TurnContext>) -> Self {
         Self {
-            guardian_ticket: turn
+            parent_response_id: turn
                 .extension_data
-                .get::<codex_protocol::guardian_ticket::GuardianTicket>()
-                .as_deref()
-                .cloned(),
+                .get::<codex_api::ResponseId>()
+                .map(|id| id.0.clone()),
             environments: turn.environments.clone(),
             model_info: Arc::clone(turn.model_info()),
             reasoning_effort: turn.reasoning_effort().cloned(),

codex-rs/core/src/guardian/review_session.rs

@@ -1300,8 +1300,14 @@ async fn run_review_on_session(
                 }),
                 ..Default::default()
             })
+            .with_responses_metadata(
+                params
+                    .parent_context
+                    .parent_response_id
+                    .as_ref()
+                    .map(|id| HashMap::from([("parent_response_id".to_owned(), id.clone())])),
+            )
             .on_start(TurnStartOptions {
-                guardian_ticket: params.parent_context.guardian_ticket.clone(),
                 final_output_json_schema: Some(params.schema.clone()),
                 service_tier: None,
                 parent_turn_id: Some(parent_turn.sub_id.clone()),

codex-rs/core/src/responses_metadata.rs

@@ -58,8 +58,7 @@ pub(crate) const WORKSPACES_KEY: &str = "workspaces";
 // App-server clients can specify additional metadata in the `responsesapi_client_metadata` param
 // when submitting a turn, but they must not override fields owned by core.
 const RESERVED_METADATA_KEYS: &[&str] = &[
-    codex_protocol::guardian_ticket::GUARDIAN_TICKET_METADATA_KEY,
-    "guardian_ticket_requested",
+    "guardian_credits_requested",
     INSTALLATION_ID_KEY,
     X_CODEX_INSTALLATION_ID_HEADER,
     SESSION_ID_KEY,
@@ -219,8 +218,8 @@ pub(crate) enum TurnToolSource {
 /// truth.
 #[derive(Clone, Debug)]
 pub struct CodexResponsesMetadata {
-    /// Opaque runtime receipt; deliberately omitted from metadata projections.
-    pub(crate) guardian_ticket: Option<codex_protocol::guardian_ticket::GuardianTicket>,
+    /// Guardian parent reference; projected only onto a Guardian request.
+    pub(crate) parent_response_id: Option<String>,
     pub(crate) installation_id: String,
     pub(crate) session_id: String,
     pub(crate) thread_id: String,
@@ -260,7 +259,7 @@ impl CodexResponsesMetadata {
         window_id: String,
     ) -> Self {
         Self {
-            guardian_ticket: None,
+            parent_response_id: None,
             installation_id,
             session_id,
             thread_id,

codex-rs/core/src/session/review.rs

@@ -137,7 +137,6 @@ pub(super) async fn spawn_review_thread(
     extension_data.insert(parent_turn_context.skills_snapshot().as_ref().clone());
 
     let review_turn_context = TurnContext {
-        guardian_ticket: None,
         sub_id: review_turn_id.clone(),
         trace_id: current_span_trace_id(),
         realtime_active: parent_turn_context.realtime_active,

codex-rs/core/src/session/session.rs

@@ -619,7 +619,6 @@ impl Session {
             request_kind,
         );
         CodexResponsesMetadata {
-            guardian_ticket: turn_context.guardian_ticket.clone(),
             window_number: Some(window_number),
             context_window_id: Some(context_window_id),
             history_ingest_requested: turn_context

codex-rs/core/src/session/turn.rs

@@ -1437,10 +1437,10 @@ async fn run_sampling_request(
     let mut original_input = None;
     let mut executed_tool_calls_by_output = HashMap::new();
     loop {
-        // A retry must not lend a previous response's ticket to the next tool call.
+        // A retry must not attribute the next tool call to the previous response.
         turn_context
             .extension_data
-            .remove::<codex_protocol::guardian_ticket::GuardianTicket>();
+            .remove::<codex_api::ResponseId>();
         let prompt_input = if let Some(input) = initial_input.take() {
             input
         } else {
@@ -2376,9 +2376,11 @@ async fn try_run_sampling_request(
         record_turn_ttft_metric(&turn_context, &event).await;
 
         match event {
-            ResponseEvent::Created { guardian_ticket } => {
-                if let Some(ticket) = guardian_ticket {
-                    turn_context.extension_data.insert(ticket);
+            ResponseEvent::Created { response_id } => {
+                if let Some(response_id) = response_id {
+                    turn_context
+                        .extension_data
+                        .insert(codex_api::ResponseId(response_id));
                 }
             }
             ResponseEvent::OutputItemDone(mut item) => {

codex-rs/core/src/session/turn_context.rs

@@ -185,7 +185,6 @@ impl std::fmt::Debug for TurnEnvironment {
 /// Request options for one turn, separate from persistent thread settings.
 #[derive(Default)]
 pub(crate) struct NewTurnContextOptions {
-    pub(crate) guardian_ticket: Option<codex_protocol::guardian_ticket::GuardianTicket>,
     pub(crate) final_output_json_schema: Option<Value>,
     pub(crate) cyber_access_program: Option<CyberAccessProgram>,
 }
@@ -193,8 +192,6 @@ pub(crate) struct NewTurnContextOptions {
 /// The context needed for a single turn of the thread.
 #[derive(Debug)]
 pub struct TurnContext {
-    /// Receipt selected for this Guardian turn, separate from its own responses.
-    pub(crate) guardian_ticket: Option<codex_protocol::guardian_ticket::GuardianTicket>,
     pub(crate) sub_id: String,
     pub(crate) trace_id: Option<String>,
     pub(crate) realtime_active: bool,
@@ -540,7 +537,6 @@ impl TurnContext {
             windows_sandbox_level: self.windows_sandbox_level,
             available_models,
             unified_exec_shell_mode: self.unified_exec_shell_mode.clone(),
-            guardian_ticket: self.guardian_ticket.clone(),
             final_output_json_schema: self.final_output_json_schema.clone(),
             dynamic_tools: self.dynamic_tools.clone(),
             turn_metadata_state: self.turn_metadata_state.clone(),
@@ -785,7 +781,6 @@ impl Session {
         let extension_data = Arc::new(codex_extension_api::ExtensionData::new(sub_id.clone()));
         extension_data.insert(skills_snapshot);
         TurnContext {
-            guardian_ticket: None,
             sub_id,
             trace_id: current_span_trace_id(),
             realtime_active: false,
@@ -1040,7 +1035,6 @@ impl Session {
         turn_context.extension_data.insert(trusted_plugin_roots);
         turn_context.realtime_active = self.conversation.running_state().await.is_some();
 
-        turn_context.guardian_ticket = options.guardian_ticket;
         turn_context.final_output_json_schema = options.final_output_json_schema;
         if turn_context.config.model_provider_id == codex_model_provider_info::OPENAI_PROVIDER_ID {
             turn_context.cyber_access_program = options.cyber_access_program;

codex-rs/core/src/session/turn_input.rs

@@ -121,7 +121,6 @@ impl PreparedTurnInputSettings {
         kind: TurnStartKind,
     ) -> CodexResult<Option<Arc<TurnContext>>> {
         let TurnStartOptions {
-            guardian_ticket,
             turn_trigger,
             final_output_json_schema,
             service_tier,
@@ -139,7 +138,6 @@ impl PreparedTurnInputSettings {
         updates.service_tier_for_turn = service_tier;
 
         let options = NewTurnContextOptions {
-            guardian_ticket,
             final_output_json_schema,
             cyber_access_program,
         };

codex-rs/core/src/tasks/mod.rs

@@ -473,7 +473,6 @@ impl Session {
             .new_turn_with_default_settings(
                 sub_id,
                 NewTurnContextOptions {
-                    guardian_ticket: start_options.guardian_ticket,
                     final_output_json_schema: start_options.final_output_json_schema,
                     cyber_access_program: start_options.cyber_access_program,
                 },

codex-rs/core/src/turn_metadata.rs

@@ -393,6 +393,14 @@ impl TurnMetadataState {
             .read()
             .unwrap_or_else(std::sync::PoisonError::into_inner)
             .clone();
+        // Extract Guardian's internal parent before filtering configured metadata keys.
+        // Ordinary app-server client metadata stays in `extra`.
+        let parent_response_id =
+            if self.subagent_header.as_deref() == Some(crate::guardian::GUARDIAN_REVIEWER_NAME) {
+                extra.remove("parent_response_id")
+            } else {
+                None
+            };
         for key in self
             .responses_api_metadata
             .read()
@@ -402,6 +410,7 @@ impl TurnMetadataState {
             extra.remove(key);
         }
         let mut metadata = CodexResponsesMetadata {
+            parent_response_id,
             turn_id: Some(self.turn_id.clone()),
             agent_name: Some(self.agent_name.clone()),
             forked_from_thread_id: self.forked_from_thread_id,

codex-rs/core/src/turn_timing_tests.rs

@@ -29,9 +29,7 @@ async fn turn_timing_state_records_ttft_only_once_per_turn() {
     state.mark_turn_started(Instant::now()).await;
     assert_eq!(
         state
-            .record_ttft_for_response_event(&ResponseEvent::Created {
-                guardian_ticket: None
-            })
+            .record_ttft_for_response_event(&ResponseEvent::Created { response_id: None })
             .await,
         None
     );