fix: extract nested provider response models

crates/aether-usage/runtime/src/event_wire.rs

@@ -242,8 +242,10 @@ impl WireOverrides {
             metadata,
             request_body,
             data.request_body_state,
+            data.api_format.as_deref(),
             data.response_body.as_ref(),
             data.response_body_state,
+            data.endpoint_api_format.as_deref(),
         );
         // Billing reads raw-body TTL before metadata regardless of capture state.
         // Preserve that precedence independently of reasoning and tier authority.

crates/aether-usage/runtime/src/record.rs

@@ -90,8 +90,10 @@ pub fn build_upsert_usage_record_from_event(
         data.request_metadata,
         data.request_body.as_ref(),
         data.request_body_state,
+        data.api_format.as_deref(),
         data.response_body.as_ref(),
         data.response_body_state,
+        data.endpoint_api_format.as_deref(),
     );
     let now_unix_secs = event.timestamp_ms / 1_000;
 

crates/aether-usage/runtime/src/request_metadata.rs

@@ -255,8 +255,10 @@ pub(crate) fn attach_provider_response_model_metadata(
     metadata: Option<Value>,
     request_body: Option<&Value>,
     request_body_state: Option<UsageBodyCaptureState>,
+    request_api_format: Option<&str>,
     response_body: Option<&Value>,
     response_body_state: Option<UsageBodyCaptureState>,
+    provider_api_format: Option<&str>,
 ) -> Option<Value> {
     let both_bodies_are_authoritative =
         usage_body_capture_is_authoritative(request_body, request_body_state)
@@ -264,8 +266,10 @@ pub(crate) fn attach_provider_response_model_metadata(
     let response_model = extract_provider_response_model_from_bodies(
         request_body,
         request_body_state,
+        request_api_format,
         response_body,
         response_body_state,
+        provider_api_format,
     );
     if !both_bodies_are_authoritative && response_model.is_none() {
         return metadata;
@@ -293,8 +297,10 @@ pub(crate) fn refresh_provider_response_model_metadata(
     metadata: Option<Value>,
     request_body: Option<&Value>,
     request_body_state: Option<UsageBodyCaptureState>,
+    request_api_format: Option<&str>,
     response_body: Option<&Value>,
     response_body_state: Option<UsageBodyCaptureState>,
+    provider_api_format: Option<&str>,
 ) -> Option<Value> {
     let mut object = match metadata {
         Some(Value::Object(object)) => object,
@@ -308,8 +314,10 @@ pub(crate) fn refresh_provider_response_model_metadata(
         if let Some(response_model) = extract_provider_response_model_from_bodies(
             request_body,
             request_body_state,
+            request_api_format,
             response_body,
             response_body_state,
+            provider_api_format,
         ) {
             object.insert(
                 PROVIDER_RESPONSE_MODEL_METADATA_KEY.to_string(),
@@ -881,8 +889,10 @@ mod tests {
             Some(json!({"provider_response_model": "old-model", "trace_id": "trace-1"})),
             Some(&json!({"model": "gpt-5"})),
             Some(UsageBodyCaptureState::Inline),
+            Some("openai:chat"),
             Some(&json!({"model": "gpt-5.1"})),
             Some(UsageBodyCaptureState::Inline),
+            Some("openai:chat"),
         )
         .expect("response model should be attached");
         assert_eq!(metadata["provider_response_model"], "gpt-5.1");
@@ -892,8 +902,10 @@ mod tests {
             Some(json!({"provider_response_model": "gpt-5.1"})),
             Some(&json!({"model": "gpt-5"})),
             Some(UsageBodyCaptureState::Inline),
+            Some("openai:chat"),
             Some(&json!({"model": "gpt-5"})),
             Some(UsageBodyCaptureState::Inline),
+            Some("openai:chat"),
         );
         assert!(metadata.is_none());
 
@@ -901,8 +913,10 @@ mod tests {
             Some(json!({"provider_response_model": "gpt-5.1"})),
             None,
             Some(UsageBodyCaptureState::Disabled),
+            Some("openai:chat"),
             Some(&json!({"model": "gpt-5.2"})),
             Some(UsageBodyCaptureState::Inline),
+            Some("openai:chat"),
         );
         assert!(metadata.is_none());
     }

crates/aether-usage/runtime/src/runtime.rs

@@ -5304,8 +5304,10 @@ fn preserve_provider_response_facts(event: &mut UsageEvent) {
         metadata,
         event.data.request_body.as_ref(),
         event.data.request_body_state,
+        event.data.api_format.as_deref(),
         event.data.response_body.as_ref(),
         event.data.response_body_state,
+        event.data.endpoint_api_format.as_deref(),
     );
 }
 

crates/aether-usage/runtime/src/write.rs

@@ -729,8 +729,10 @@ fn build_terminal_usage_event_from_seed_impl(
         request_metadata,
         request_body.as_ref(),
         body_states.request_body_state,
+        Some(client_contract.as_str()),
         provider_response.as_ref(),
         body_states.response_body_state,
+        Some(provider_contract.as_str()),
     );
 
     let mut data = UsageEventData {
@@ -1059,8 +1061,10 @@ pub fn build_sync_terminal_usage_seed(
         request_metadata,
         context_seed.request_body.as_ref(),
         context_seed.body_states.request_body_state,
+        Some(context_seed.client_contract.as_str()),
         provider_response_full.as_ref(),
         provider_response_body_state,
+        Some(context_seed.provider_contract.as_str()),
     );
 
     TerminalUsageSeed {
@@ -1244,8 +1248,10 @@ pub fn build_stream_terminal_usage_seed(
         request_metadata,
         context_seed.request_body.as_ref(),
         context_seed.body_states.request_body_state,
+        Some(context_seed.client_contract.as_str()),
         provider_response_full.as_ref(),
         provider_response_body_state,
+        Some(context_seed.provider_contract.as_str()),
     );
     // The parser's terminal summary is authoritative when a response body is truncated or the
     // body and summary disagree; attach it after the body refresh so it wins.