Codex with ChatGPT: Connect Your ChatGPT Web Subscription as the Planning Brain for Codex

Developer XiaoDuoYa released Codex with ChatGPT, an open-source bridge that connects a ChatGPT web subscription to a local Codex terminal session via a read-only Model Context Protocol (MCP) server. The tool lets ChatGPT handle high-context planning and code review while Codex executes edits, aiming to cut API token costs by using flat-rate web quotas. The bridge uses OAuth 2.1 authentication and exposes only read tools such as read_file, git_diff, and test_status, with no write, delete, or shell execution capabilities.

Autonomous coding agents such as OpenAI Codex and Claude Code have revolutionized local software development. However, running high-reasoning models across entire codebases to draft architectural plans, design specifications, and review multi-file pull requests consumes millions of expensive API tokens. Paradoxically, many engineers pay for flat-rate monthly subscriptions like ChatGPT Plus or Pro whose generous web quotas sit underutilized while their command-line API bills mount. Codex with ChatGPT is an open-source bridge developed by XiaoDuoYa. Operating on the core philosophy "ChatGPT thinks. Codex works." , it links the official ChatGPT web interface to your local Codex terminal session through a secure, read-only Model Context Protocol MCP bridge. Codex with ChatGPT separates software development into two distinct layers: Rather than copying and pasting files manually or routing code through untrusted third-party reverse proxies, ChatGPT reads only the specific lines of code it requires via an OAuth 2.1-authenticated local MCP bridge. By offloading high-context architectural reasoning and code reviews to the ChatGPT web client, developers eliminate repetitive token burn on planning tasks. Codex only uses tokens when executing code edits and terminal commands. Security is enforced by design: read file , git diff , test status , etc. . No write, delete, or shell execution tools exist on the bridge server, eliminating prompt injection risks. .env , private keys, and credential stores are blocked by default. Once Codex finishes modifying files and running test suites, ChatGPT does not rely on text summaries. Instead, it inspects the actual git diff and test execution records through the MCP data plane to verify correctness before signing off. The project includes a streamlined Codex skill that automates full environment setup: Instruct your Codex agent directly: Please install and configure "Codex with ChatGPT" for me, fully automatically. Codex checks system prerequisites, compiles the local bridge, provisions the tunnel, and establishes the pairing connection without manual configuration. By combining the conversational reasoning depth of ChatGPT web with the local execution power of Codex, Codex with ChatGPT offers an economical and disciplined approach to agentic development. Want to connect your web subscription to Codex? Check out the Codex with ChatGPT GitHub Repository https://github.com/XiaoDuoYa/codex-with-chatgpt .