matchameleon/gpt-codex-plugin

GPT Relay Codex Plugin is a plugin for Codex, OpenAI's coding agent, that lets Codex send prompts to ChatGPT using your own existing Chrome browser session. Instead of connecting through an API, it drives the actual ChatGPT web page, then sends the finished reply, any generated images, Deep Research reports, and conversation links back to Codex. It is an independent community project and is not an official OpenAI or ChatGPT product. The plugin is meant for people who want Codex to be able to ask ChatGPT while choosing the same visible options you would pick by hand in the ChatGPT interface, such as different model and mode choices, Deep Research, web search, image generation, and file uploads. It can switch to a specific model or mode when asked, and it will refuse clearly if your account does not have access to that option rather than quietly falling back to something else. Installing it requires Codex with plugin support, plus the official Codex Chrome extension installed, enabled, and signed into a working ChatGPT session in Chrome. You add the plugin's repository as a marketplace source either from the Codex plugin menu or with a command line call, then install and start a new Codex thread. If you want the plugin to upload local files or images to ChatGPT, you also need to turn on file URL access for the Codex Chrome extension in Chrome's extension settings. Once set up, a user can type a prompt in Codex such as asking it to use a specific model to analyze a question, or asking it to run Deep Research on a topic, and the plugin handles sending that to ChatGPT and returning the formatted answer, including headings, lists, tables, and code blocks. There is also an optional Redis setup for people running multiple copies of the plugin against one shared Chrome profile, which coordinates browser access and can cache session state across processes. Without Redis configured, everything still works as normal. The project notes that since it relies on the visible ChatGPT web page, it can be affected by future ChatGPT interface changes, and it will pause on login prompts, CAPTCHAs, or other account permission dialogs.