codex - 💡(How to fix) Fix Built-in amazon-bedrock provider uses outdated Mantle endpoint path (/openai/v1/responses)

What issue are you seeing?

Summary

Codex CLI v0.132.0 appears to use an outdated AWS Bedrock Mantle endpoint path when using the built-in amazon-bedrock provider.

The built-in provider sends requests to:

/openai/v1/responses

However, current AWS Bedrock Mantle documentation specifies:

/v1/responses

This causes requests to fail with 404.

Environment

• Codex CLI: v0.132.0
• AWS Region: ap-northeast-1
• Model: openai.gpt-oss-120b

Current config

profile = "bedrock-profile"

[model_providers.amazon-bedrock]
model_provider = "amazon-bedrock"

[profiles.bedrock-profile]
model_provider = "amazon-bedrock"
model = "openai.gpt-oss-120b"

Actual request URL

Codex sends requests to:

https://bedrock-mantle.ap-northeast-1.api.aws/openai/v1/responses

This returns:

404 Not Found

Verification performed

Using a custom OpenAI provider configuration, I verified that:

https://bedrock-mantle.ap-northeast-1.api.aws/v1/responses

exists and responds correctly.

Example result:

401 Unauthorized: Invalid bearer token

This confirms that:

• /v1/responses exists
• Bedrock Mantle Responses API is available
• openai.gpt-oss-120b supports Responses API
• the built-in provider appears to construct the wrong URL path

What steps can reproduce the bug?

Built-in amazon-bedrock provider should use:

/v1/responses

instead of:

/openai/v1/responses

What is the expected behavior?

No response

Additional information

No response