Connecting Codex in ChatGPT Plus to the UEFN MCP server
A four-step guide to adding UEFN's built-in MCP server to Codex in the Windows ChatGPT desktop app so the AI edits scripts until the build compiles.
codex is already in your £20 chatgpt plus, so start there: 1/ get the new chatgpt desktop app for windows, sign in with the same account, pick Codex from the top-left menu 2/ in uefn: Project → Project Settings, Beta Access at the bottom. tick Python Editor Scripting + UEFN MCP Toolsets, restart uefn 3/ with uefn open, in codex: Settings → MCP servers → Add server. name: unreal-mcp, type: Streamable HTTP, url: http://127.0.0.1:8000/mcp. save the server, then hit Restart 4/ save your project (it's beta, the editor can freeze). open its folder in codex (trust it if asked) and ask "add a log when the round starts, then compile it" it can keep fixing its compile errors till the build is green. the server lives in uefn, not in codex, so you can add claude code later if you want. it's a separate bill (claude pro or higher, or api credits)