Building interactive widgets for ChatGPT turned out to be way more complex than I expected. Between the MCP protocol, widget registration, build setup, CSP policies, and resource serving — I kept writing the same boilerplate over and over just to get something basic working.

That’s why I built FastApps, an open-source framework that lets you build ChatGPT apps with only two files: a Python backend and a React frontend.

It removes all the glue code and focuses on developer experience:

- Auto-discovers and registers MCP widgets automatically

- Builds and bundles React UIs with zero config

- Manages CSP, metadata, and resource serving out of the box

- Type-safe data flow with Pydantic and React hooks

- Runs as an MCP server, fully compatible with ChatGPT and other MCP clients

If you’ve been experimenting with MCP or building ChatGPT tools, I’d love your feedback. It’s fully open source — and I’m looking for contributors who want to help shape this ecosystem together.

GitHub → https://github.com/DooiLabs/FastApps

Docs → https://www.fastapps.org/