Codex + Tencent LKEAP 401: It Was Not the Key

Description and use

A 401 error was caused by a protocol mismatch between Codex (Responses API) and Tencent LKEAP (Chat Completions). A local Node.js proxy was created to translate requests, and the configuration was updated accordingly.

Problem

Codex misinterpreted a Tencent LKEAP endpoint as a Responses API, appending "/responses" to a Chat Completions URL and causing a 401 error.

Outcome

The 401 error was caused by a protocol mismatch; a local proxy successfully bridged the gap, allowing Codex to communicate with Tencent LKEAP.

Workflow

• Inspect the final request URL for unexpected path patterns.
• Confirm the client’s wire protocol (Responses vs Chat Completions).
• Verify the upstream endpoint’s expected URL shape.
• If mismatch, either adjust the client config or implement a local protocol adapter.
• Set up a local Node.js proxy that forwards Responses requests to the correct Chat Completions URL.
• Configure Codex to point to the proxy and provide a dummy OPENAI_API_KEY.
• Test the setup with a real Tencent LKEAP API key and validate responses.
• Document any remaining gaps (streaming, tool‑call traffic, error mapping).

Evidence

unexpected status 401 Unauthorized

Source

invalid configuration: wire_api = "chat" is no longer supported.

Source