diff --git a/codex-rs/codex-api/src/endpoint/models.rs b/codex-rs/codex-api/src/endpoint/models.rs
index b15f07fca2..7f21c77635 100644
--- a/codex-rs/codex-api/src/endpoint/models.rs
+++ b/codex-rs/codex-api/src/endpoint/models.rs
@@ -5,6 +5,7 @@ use crate::provider::Provider;
 use crate::telemetry::run_with_request_telemetry;
 use codex_client::HttpTransport;
 use codex_client::RequestTelemetry;
+use codex_protocol::openai_models::ModelInfo;
 use codex_protocol::openai_models::ModelsResponse;
 use http::HeaderMap;
 use http::Method;
@@ -41,7 +42,7 @@ impl<T: HttpTransport, A: AuthProvider> ModelsClient<T, A> {
         &self,
         client_version: &str,
         extra_headers: HeaderMap,
-    ) -> Result<ModelsResponse, ApiError> {
+    ) -> Result<(Vec<ModelInfo>, Option<String>), ApiError> {
         let builder = || {
             let mut req = self.provider.build_request(Method::GET, self.path());
             req.headers.extend(extra_headers.clone());
@@ -66,7 +67,7 @@ impl<T: HttpTransport, A: AuthProvider> ModelsClient<T, A> {
             .and_then(|value| value.to_str().ok())
             .map(ToString::to_string);
 
-        let ModelsResponse { models, etag } = serde_json::from_slice::<ModelsResponse>(&resp.body)
+        let ModelsResponse { models } = serde_json::from_slice::<ModelsResponse>(&resp.body)
             .map_err(|e| {
                 ApiError::Stream(format!(
                     "failed to decode models response: {e}; body: {}",
@@ -74,9 +75,7 @@ impl<T: HttpTransport, A: AuthProvider> ModelsClient<T, A> {
                 ))
             })?;
 
-        let etag = header_etag.unwrap_or(etag);
-
-        Ok(ModelsResponse { models, etag })
+        Ok((models, header_etag))
     }
 }
 
@@ -102,16 +101,15 @@ mod tests {
     struct CapturingTransport {
         last_request: Arc<Mutex<Option<Request>>>,
         body: Arc<ModelsResponse>,
+        response_etag: Arc<Option<String>>,
     }
 
     impl Default for CapturingTransport {
         fn default() -> Self {
             Self {
                 last_request: Arc::new(Mutex::new(None)),
-                body: Arc::new(ModelsResponse {
-                    models: Vec::new(),
-                    etag: String::new(),
-                }),
+                body: Arc::new(ModelsResponse { models: Vec::new() }),
+                response_etag: Arc::new(None),
             }
         }
     }
@@ -122,8 +120,8 @@ mod tests {
             *self.last_request.lock().unwrap() = Some(req);
             let body = serde_json::to_vec(&*self.body).unwrap();
             let mut headers = HeaderMap::new();
-            if !self.body.etag.is_empty() {
-                headers.insert(ETAG, self.body.etag.parse().unwrap());
+            if let Some(etag) = self.response_etag.as_ref().as_deref() {
+                headers.insert(ETAG, etag.parse().unwrap());
             }
             Ok(Response {
                 status: StatusCode::OK,
@@ -166,14 +164,12 @@ mod tests {
 
     #[tokio::test]
     async fn appends_client_version_query() {
-        let response = ModelsResponse {
-            models: Vec::new(),
-            etag: String::new(),
-        };
+        let response = ModelsResponse { models: Vec::new() };
 
         let transport = CapturingTransport {
             last_request: Arc::new(Mutex::new(None)),
             body: Arc::new(response),
+            response_etag: Arc::new(None),
         };
 
         let client = ModelsClient::new(
@@ -182,12 +178,12 @@ mod tests {
             DummyAuth,
         );
 
-        let result = client
+        let (models, _etag) = client
             .list_models("0.99.0", HeaderMap::new())
             .await
             .expect("request should succeed");
 
-        assert_eq!(result.models.len(), 0);
+        assert_eq!(models.len(), 0);
 
         let url = transport
             .last_request
@@ -232,12 +228,12 @@ mod tests {
                 }))
                 .unwrap(),
             ],
-            etag: String::new(),
         };
 
         let transport = CapturingTransport {
             last_request: Arc::new(Mutex::new(None)),
             body: Arc::new(response),
+            response_etag: Arc::new(None),
         };
 
         let client = ModelsClient::new(
@@ -246,27 +242,25 @@ mod tests {
             DummyAuth,
         );
 
-        let result = client
+        let (models, _etag) = client
             .list_models("0.99.0", HeaderMap::new())
             .await
             .expect("request should succeed");
 
-        assert_eq!(result.models.len(), 1);
-        assert_eq!(result.models[0].slug, "gpt-test");
-        assert_eq!(result.models[0].supported_in_api, true);
-        assert_eq!(result.models[0].priority, 1);
+        assert_eq!(models.len(), 1);
+        assert_eq!(models[0].slug, "gpt-test");
+        assert_eq!(models[0].supported_in_api, true);
+        assert_eq!(models[0].priority, 1);
     }
 
     #[tokio::test]
     async fn list_models_includes_etag() {
-        let response = ModelsResponse {
-            models: Vec::new(),
-            etag: "\"abc\"".to_string(),
-        };
+        let response = ModelsResponse { models: Vec::new() };
 
         let transport = CapturingTransport {
             last_request: Arc::new(Mutex::new(None)),
             body: Arc::new(response),
+            response_etag: Arc::new(Some("\"abc\"".to_string())),
         };
 
         let client = ModelsClient::new(
@@ -275,12 +269,12 @@ mod tests {
             DummyAuth,
         );
 
-        let result = client
+        let (models, etag) = client
             .list_models("0.1.0", HeaderMap::new())
             .await
             .expect("request should succeed");
 
-        assert_eq!(result.models.len(), 0);
-        assert_eq!(result.etag, "\"abc\"");
+        assert_eq!(models.len(), 0);
+        assert_eq!(etag.as_deref(), Some("\"abc\""));
     }
 }
diff --git a/codex-rs/codex-api/tests/models_integration.rs b/codex-rs/codex-api/tests/models_integration.rs
index 93baffd356..0b3e95ee30 100644
--- a/codex-rs/codex-api/tests/models_integration.rs
+++ b/codex-rs/codex-api/tests/models_integration.rs
@@ -90,7 +90,6 @@ async fn models_client_hits_models_endpoint() {
             reasoning_summary_format: ReasoningSummaryFormat::None,
             experimental_supported_tools: Vec::new(),
         }],
-        etag: String::new(),
     };
 
     Mock::given(method("GET"))
@@ -106,13 +105,13 @@ async fn models_client_hits_models_endpoint() {
     let transport = ReqwestTransport::new(reqwest::Client::new());
     let client = ModelsClient::new(transport, provider(&base_url), DummyAuth);
 
-    let result = client
+    let (models, _etag) = client
         .list_models("0.1.0", HeaderMap::new())
         .await
         .expect("models request should succeed");
 
-    assert_eq!(result.models.len(), 1);
-    assert_eq!(result.models[0].slug, "gpt-test");
+    assert_eq!(models.len(), 1);
+    assert_eq!(models[0].slug, "gpt-test");
 
     let received = server
         .received_requests()
diff --git a/codex-rs/core/src/openai_models/models_manager.rs b/codex-rs/core/src/openai_models/models_manager.rs
index 7f54c4f852..d6ca13e76b 100644
--- a/codex-rs/core/src/openai_models/models_manager.rs
+++ b/codex-rs/core/src/openai_models/models_manager.rs
@@ -94,12 +94,12 @@ impl ModelsManager {
         let client = ModelsClient::new(transport, api_provider, api_auth);
 
         let client_version = format_client_version_to_whole();
-        let ModelsResponse { models, etag } = client
+        let (models, etag) = client
             .list_models(&client_version, HeaderMap::new())
             .await
             .map_err(map_api_error)?;
 
-        let etag = (!etag.is_empty()).then_some(etag);
+        let etag = etag.filter(|value| !value.is_empty());
 
         self.apply_remote_models(models.clone()).await;
         *self.etag.write().await = etag.clone();
@@ -389,7 +389,6 @@ mod tests {
             &server,
             ModelsResponse {
                 models: remote_models.clone(),
-                etag: String::new(),
             },
         )
         .await;
@@ -446,7 +445,6 @@ mod tests {
             &server,
             ModelsResponse {
                 models: remote_models.clone(),
-                etag: String::new(),
             },
         )
         .await;
@@ -501,7 +499,6 @@ mod tests {
             &server,
             ModelsResponse {
                 models: initial_models.clone(),
-                etag: String::new(),
             },
         )
         .await;
@@ -542,7 +539,6 @@ mod tests {
             &server,
             ModelsResponse {
                 models: updated_models.clone(),
-                etag: String::new(),
             },
         )
         .await;
@@ -576,7 +572,6 @@ mod tests {
             &server,
             ModelsResponse {
                 models: initial_models,
-                etag: String::new(),
             },
         )
         .await;
@@ -605,7 +600,6 @@ mod tests {
             &server,
             ModelsResponse {
                 models: refreshed_models,
-                etag: String::new(),
             },
         )
         .await;
diff --git a/codex-rs/core/tests/common/responses.rs b/codex-rs/core/tests/common/responses.rs
index b98b29625e..8fcabdda54 100644
--- a/codex-rs/core/tests/common/responses.rs
+++ b/codex-rs/core/tests/common/responses.rs
@@ -677,14 +677,7 @@ pub async fn start_mock_server() -> MockServer {
         .await;
 
     // Provide a default `/models` response so tests remain hermetic when the client queries it.
-    let _ = mount_models_once(
-        &server,
-        ModelsResponse {
-            models: Vec::new(),
-            etag: String::new(),
-        },
-    )
-    .await;
+    let _ = mount_models_once(&server, ModelsResponse { models: Vec::new() }).await;
 
     server
 }
diff --git a/codex-rs/core/tests/suite/remote_models.rs b/codex-rs/core/tests/suite/remote_models.rs
index 3c4d389ec0..4086732c2b 100644
--- a/codex-rs/core/tests/suite/remote_models.rs
+++ b/codex-rs/core/tests/suite/remote_models.rs
@@ -93,7 +93,6 @@ async fn remote_models_remote_model_uses_unified_exec() -> Result<()> {
         &server,
         ModelsResponse {
             models: vec![remote_model],
-            etag: String::new(),
         },
     )
     .await;
@@ -232,7 +231,6 @@ async fn remote_models_apply_remote_base_instructions() -> Result<()> {
         &server,
         ModelsResponse {
             models: vec![remote_model],
-            etag: String::new(),
         },
     )
     .await;
@@ -310,7 +308,6 @@ async fn remote_models_preserve_builtin_presets() -> Result<()> {
         &server,
         ModelsResponse {
             models: vec![remote_model.clone()],
-            etag: String::new(),
         },
     )
     .await;
@@ -368,7 +365,6 @@ async fn remote_models_hide_picker_only_models() -> Result<()> {
         &server,
         ModelsResponse {
             models: vec![remote_model],
-            etag: String::new(),
         },
     )
     .await;
diff --git a/codex-rs/protocol/src/openai_models.rs b/codex-rs/protocol/src/openai_models.rs
index 28b25bb604..4cdc0e4ba6 100644
--- a/codex-rs/protocol/src/openai_models.rs
+++ b/codex-rs/protocol/src/openai_models.rs
@@ -197,8 +197,6 @@ pub struct ModelInfo {
 #[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq, TS, JsonSchema, Default)]
 pub struct ModelsResponse {
     pub models: Vec<ModelInfo>,
-    #[serde(default)]
-    pub etag: String,
 }
 
 // convert ModelInfo to ModelPreset