From 8f103417ef3e63193561d7b3d8ff4cf9b91335de Mon Sep 17 00:00:00 2001
From: Celia Chen <celia@openai.com>
Date: Thu, 24 Sep 2026 22:58:51 +0000
Subject: [PATCH] Preserve the client-agent header for Amazon Bedrock Runtime
 (#47964)

## What changed

Keep `x-amzn-mantle-client-agent: codex` in the Amazon Bedrock Runtime provider instead of clearing the headers inherited from the Amazon Bedrock provider.

## Testing

Update provider construction expectations and extend the API provider header test to cover both Amazon Bedrock providers.

GitOrigin-RevId: eab07f347b53f0a6ba2e224a39590f49f181363e
---
 codex-rs/model-provider-info/src/lib.rs       |  1 -
 .../src/model_provider_info_tests.rs          | 35 ++++++++++++-------
 2 files changed, 22 insertions(+), 14 deletions(-)

diff --git a/codex-rs/model-provider-info/src/lib.rs b/codex-rs/model-provider-info/src/lib.rs
index eef9b2129c..e5d31ce3a9 100644
--- a/codex-rs/model-provider-info/src/lib.rs
+++ b/codex-rs/model-provider-info/src/lib.rs
@@ -593,7 +593,6 @@ other non-default provider fields are not supported"
     ) -> ModelProviderInfo {
         let mut provider = Self::create_amazon_bedrock_provider(aws);
         provider.name = AMAZON_BEDROCK_RUNTIME_PROVIDER_NAME.into();
-        provider.http_headers = None;
         provider
     }
 
diff --git a/codex-rs/model-provider-info/src/model_provider_info_tests.rs b/codex-rs/model-provider-info/src/model_provider_info_tests.rs
index c0c3971936..2929adfd98 100644
--- a/codex-rs/model-provider-info/src/model_provider_info_tests.rs
+++ b/codex-rs/model-provider-info/src/model_provider_info_tests.rs
@@ -354,7 +354,6 @@ fn test_create_amazon_bedrock_provider() {
 fn test_create_amazon_bedrock_runtime_provider() {
     let mut expected = ModelProviderInfo::create_amazon_bedrock_provider(/*aws*/ None);
     expected.name = "Amazon Bedrock Runtime".to_string();
-    expected.http_headers = None;
 
     assert_eq!(
         ModelProviderInfo::create_amazon_bedrock_runtime_provider(/*aws*/ None),
@@ -387,7 +386,10 @@ fn test_create_amazon_bedrock_runtime_provider_with_aws_configuration() {
                 credential_export: None,
                 auth_refresh: None,
             }),
-            None,
+            Some(maplit::hashmap! {
+                AMAZON_BEDROCK_MANTLE_CLIENT_AGENT_HEADER.to_string() =>
+                    AMAZON_BEDROCK_MANTLE_CLIENT_AGENT_VALUE.into(),
+            }),
             false,
         )
     );
@@ -407,18 +409,25 @@ fn provider_auth_for_test() -> ModelProviderAuthInfo {
 }
 
 #[test]
-fn test_amazon_bedrock_provider_adds_mantle_client_agent_header() {
-    let api_provider = ModelProviderInfo::create_amazon_bedrock_provider(/*aws*/ None)
-        .to_api_provider(/*auth_mode*/ None)
-        .expect("Amazon Bedrock provider should build API provider");
+fn test_amazon_bedrock_providers_add_mantle_client_agent_header() {
+    for provider in [
+        ModelProviderInfo::create_amazon_bedrock_provider(/*aws*/ None),
+        ModelProviderInfo::create_amazon_bedrock_runtime_provider(/*aws*/ None),
+    ] {
+        let api_provider = provider
+            .to_api_provider(/*auth_mode*/ None)
+            .expect("Amazon Bedrock provider should build API provider");
 
-    assert_eq!(
-        api_provider
-            .headers
-            .get(AMAZON_BEDROCK_MANTLE_CLIENT_AGENT_HEADER)
-            .and_then(|value| value.to_str().ok()),
-        Some(AMAZON_BEDROCK_MANTLE_CLIENT_AGENT_VALUE)
-    );
+        assert_eq!(
+            api_provider
+                .headers
+                .get(AMAZON_BEDROCK_MANTLE_CLIENT_AGENT_HEADER)
+                .and_then(|value| value.to_str().ok()),
+            Some(AMAZON_BEDROCK_MANTLE_CLIENT_AGENT_VALUE),
+            "provider: {}",
+            provider.name
+        );
+    }
 }
 
 #[test]