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/ext/guardian-v2/src/async_scorer/extension.rs

@@ -512,11 +512,10 @@ impl GuardianV2Extension {
         let thread_id = input.thread_store.level_id().to_owned();
         let turn_id = input.turn_id.to_owned();
         let root_turn_id = input.root_turn_id.map(str::to_owned);
-        let guardian_ticket = input
+        let parent_response_id = input
             .turn_store
-            .get::<codex_protocol::guardian_ticket::GuardianTicket>()
-            .as_deref()
-            .cloned();
+            .get::<codex_api::ResponseId>()
+            .map(|id| id.0.clone());
         let thread_context: Result<_, String> = async {
             let parsed_thread_id =
                 ThreadId::from_string(&thread_id).map_err(|error| error.to_string())?;
@@ -839,7 +838,7 @@ impl GuardianV2Extension {
                 let instructions = guardian_config.render_classifier_instructions(policy);
                 let output = match sampler
                     .sample(LunaSamplingRequest {
-                        guardian_ticket,
+                        parent_response_id,
                         instructions,
                         trusted_review_evidence,
                         trusted_tool_context,

codex-rs/ext/guardian-v2/src/async_scorer/sampler.rs

@@ -90,8 +90,8 @@ pub struct LunaSamplerConfig {
 
 /// One tool-less Luna classification request over an already-open connection.
 pub struct LunaSamplingRequest {
-    /// Runtime receipt of the response handling the classified tool.
-    pub guardian_ticket: Option<codex_protocol::guardian_ticket::GuardianTicket>,
+    /// ID of the response handling the classified tool.
+    pub parent_response_id: Option<String>,
     /// Trusted instructions describing the requested classification.
     pub instructions: String,
     /// Host-supplied Guardian reviews isolated from untrusted transcript entries.
@@ -454,7 +454,7 @@ impl LunaSampler {
         }
         // A classification is its own inference turn; retries keep that identity.
         let turn_id = Uuid::now_v7().to_string();
-        let guardian_ticket = request.guardian_ticket;
+        let parent_response_id = request.parent_response_id;
         let parent_turn_id = request.parent_turn_id;
         let root_turn_id = request.root_turn_id;
         let mut input = vec![
@@ -629,6 +629,11 @@ impl LunaSampler {
                 turn_metadata["root_turn_id"] = json!(root_turn_id);
             }
             client_metadata.insert(TURN_METADATA_KEY.to_owned(), turn_metadata.to_string());
+            if lease.connection.endpoint == ResponsesEndpoint::GuardianClassifier
+                && let Some(parent_response_id) = &parent_response_id
+            {
+                client_metadata.insert("parent_response_id".to_owned(), parent_response_id.clone());
+            }
             request.client_metadata = Some(client_metadata);
             let mut stream = match lease
                 .connection
@@ -637,7 +642,6 @@ impl LunaSampler {
                     ResponsesWsRequest::ResponseCreate((&request).into()),
                     /*connection_reused*/ true,
                     /*turn_state*/ None,
-                    guardian_ticket.as_ref(),
                 )
                 .await
             {

codex-rs/ext/guardian-v2/src/async_scorer/sampler_tests.rs

@@ -192,7 +192,7 @@ async fn connect_sampler(config: LunaSamplerConfig) -> Result<LunaSampler> {
 
 fn sample_request(parent_turn_id: &str) -> LunaSamplingRequest {
     LunaSamplingRequest {
-        guardian_ticket: None,
+        parent_response_id: None,
         instructions: "Return high for high risk or low for low risk.".to_owned(),
         trusted_review_evidence: Vec::new(),
         trusted_tool_context: None,
@@ -447,7 +447,7 @@ async fn preconnected_sampler_reuses_authenticated_websocket_for_classifications
 
     let first = sampler
         .sample(LunaSamplingRequest {
-            guardian_ticket: None,
+            parent_response_id: None,
             instructions: "Return high for high risk or low for low risk.".to_owned(),
             trusted_review_evidence: Vec::new(),
             trusted_tool_context: None,
@@ -479,7 +479,7 @@ async fn preconnected_sampler_reuses_authenticated_websocket_for_classifications
     manager.refresh_token_from_authority().await?;
     let second = sampler
         .sample(LunaSamplingRequest {
-            guardian_ticket: None,
+            parent_response_id: None,
             instructions: "Return high for high risk or low for low risk.".to_owned(),
             trusted_review_evidence: Vec::new(),
             trusted_tool_context: None,
@@ -655,7 +655,7 @@ async fn sampler_returns_classification_token_before_terminal_response_events()
     let output = tokio::time::timeout(
         Duration::from_secs(2),
         sampler.sample(LunaSamplingRequest {
-            guardian_ticket: None,
+            parent_response_id: None,
             instructions: "Return high for high risk or low for low risk.".to_owned(),
             trusted_review_evidence: Vec::new(),
             trusted_tool_context: None,
@@ -1119,7 +1119,7 @@ async fn sampler_limits_transient_recovery_attempts() -> Result<()> {
 }
 
 #[tokio::test(flavor = "multi_thread", worker_threads = 2)]
-async fn guardian_ticket_survives_classifier_transport_retry() -> Result<()> {
+async fn parent_response_id_survives_classifier_transport_retry() -> Result<()> {
     skip_if_no_network!(Ok(()));
     for free_guardian in [false, true] {
         let healthy = responses::start_websocket_server(vec![vec![vec![
@@ -1146,10 +1146,9 @@ async fn guardian_ticket_survives_classifier_transport_retry() -> Result<()> {
             );
         }
         let sampler = connect_sampler(config).await?;
-        let raw_ticket = "t".repeat(43);
+        let parent_response_id = "resp-parent";
         let mut request = sample_request("turn-1");
-        request.guardian_ticket =
-            codex_protocol::guardian_ticket::GuardianTicket::from_server(&raw_ticket);
+        request.parent_response_id = Some(parent_response_id.to_owned());
         assert_eq!(sampler.sample(request).await?, "low");
         for server in [&expired, &healthy] {
             let requests = server.single_connection();
@@ -1157,12 +1156,12 @@ async fn guardian_ticket_survives_classifier_transport_retry() -> Result<()> {
             let body = requests[0].body_json();
             assert_eq!(
                 (
-                    body["client_metadata"].get("guardian_ticket").cloned(),
-                    body["client_metadata"].get("guardian_ticket_requested"),
+                    body["client_metadata"].get("parent_response_id").cloned(),
+                    body["client_metadata"].get("guardian_credits_requested"),
                 ),
-                (free_guardian.then(|| json!(raw_ticket)), None)
+                (free_guardian.then(|| json!(parent_response_id)), None)
             );
-            assert!(!body["input"].to_string().contains(&raw_ticket));
+            assert!(!body["input"].to_string().contains(parent_response_id));
         }
     }