By skyforbes 
A step-by-step guide to wrapping your React Router Node backend as an MCP server, deploying it and securely integrating it into ChatGPT’s Agent Builder for real API interactions.
ChatGPT just released Agent Builder last week and honestly, it’s huge. I can already see thousands of possible use cases where end users could benefit from this AI feast.
I tinkered around a bit, spun everything up, and got a fresh taste of what it looks like when integrated into my own project.
For the demo, I’m using a simple placeholder API: https://jsonplaceholder.typicode.com/posts/${id} You can plug in any API endpoint you want, this is just to test the wiring. Eventually, I’m going to bundle this setup into my product, but first, I wanted to try it out.
The frontend is built with React Router v7 (framework mode) and a custom Node entry, which I already use to integrate API endpoints.
The main libraries that I am using here are openai and @modelcontextprotocol/sdk and also zod for the validation.
Inside your server folder (where your main app.ts file sits), create a new file…