tRPC

tRPC is an open source TypeScript library for building APIs that share types between server and client. You write functions on the server and call them from the client with full type inference.

Each server procedure has an input and an output type. The client reads those types directly from the server code, so the editor can flag wrong inputs or missing fields before the app runs. It works with common TypeScript frameworks such as Next.js and can be served from several runtimes.

• Share types between server and client code
• Query and mutation procedures with typed inputs
• Editor feedback when inputs or outputs change
• Works with Next.js and other TypeScript frameworks
• Client created with one function call

Full-stack TypeScript teams who control both the frontend and the backend and want to avoid writing separate API docs. It is less suited to public APIs that clients in other languages must consume.

The project is free and released under the MIT license. It is a library, so you add it to an existing project with a package manager. Because the types come from the server code, both the server and the client need to be written in TypeScript.