Right now it's React-first because the Apps SDK UI layer is React-based.
But the frontend is bundled automatically, so if OpenAI expands support for other frameworks later, swapping it out would be straightforward.
It’s an actual runtime, not just scaffolding. FastApps runs as an MCP server and it handles widget registration, protocol messages, static assets, and the data flow between backend and frontend.
When you run fastapps create, you get a running service that ChatGPT talks to over MCP, not just a code template. You can extend or deploy it like any other web app.
Could you share a bit more on what you mean by “backend-only"? Are you thinking of running logic without any UI part?
Node.js isn’t supported yet, but I’d love to hear your use case!