Developer XiaoDuoYa released codex-with-chatgpt, an open-source tool that connects a ChatGPT web subscription to the Codex coding agent so ChatGPT handles planning while Codex executes the code changes, according to the project's GitHub repository. It has drawn more than 4,100 stars.
The tool works over a read-only Model Context Protocol connection secured with OAuth 2.1: ChatGPT can read specific lines of code through nine read-only tools but cannot modify files or run shell commands, and it never receives an entire repository at once, the repository says.
A local loopback HTTP server manages the connection, with an optional Cloudflare tunnel for a stable hostname across restarts, and each access token is bound to a single workspace with strict path containment, according to the project's documentation.
The pitch is direct: use a ChatGPT subscription already being paid for to do the expensive reasoning work, and save API token spend for the execution step Codex is built for.
As agent harnesses increasingly split thinking from doing across different products, the read-only, workspace-scoped access model here, wiring a planning model to an execution tool without exposing a full codebase, is worth studying regardless of whether a team uses this specific project.