OpenAI Codex CLI
Understand the Responses API compatibility blocker.
Not supported
2026-10-10. Codex CLI 0.162.1. Its configuration parser was checked locally and rejects wire_api = "chat".
Codex CLI is OpenAI's terminal coding agent. The current release requires the Responses API. unused.market exposes Chat Completions and Messages, so there is no working direct Codex CLI configuration for this gateway.
Before you start
If your goal is a working coding agent now, use Claude Code, Aider, or opencode. For application code, use the OpenAI SDK with Chat Completions.
Configure the tool
Codex stores user settings in ~/.codex/config.toml on macOS/Linux and %USERPROFILE%\.codex\config.toml on Windows. A custom base_url changes the host; it does not translate the API protocol. Setting it to https://unused.market/v1 would still make Codex request /v1/responses, which is not a public gateway route.
Do not copy older guides that recommend wire_api = "chat". Version 0.162.1 rejects that value before sending a request.
Verify the connection
There is no successful direct inference test to perform for this version. After choosing a supported agent, ask it for a one-sentence greeting and find the request in Analytics → Requests. Changing the model ID cannot fix a missing API endpoint.
Limits and troubleshooting
| Symptom | Cause and next step |
|---|---|
wire_api = "chat" is no longer supported | Current Codex accepts Responses only. Choose a compatible client. |
/v1/responses is not found | The public gateway has no Responses route. A new API key will not change this. |
A seller offering a model associated with Codex does not mean the Codex CLI protocol is exposed to buyers.
Sources and verification
Checked 2026-10-10: Codex CLI 0.162.1, including the local parser rejection. Official source: configuration reference, model_providers.<id>.wire_api and custom provider fields.