OpenAPI schema generation for tRPC

The @trpc/openapi package generates an OpenAPI 3.1 specification from your tRPC router. Use the spec to:

• Generate a typed API client in any language
• Call tRPC endpoints via HTTP tools like Postman or Insomnia
• Enable AI agent integrations which can consume OpenAPI

Install

pnpm add @trpc/openapi

Quick start

CLI

pnpm exec trpc-openapi ./src/server/router.ts

Programmatic

import { generateOpenAPIDocument } from '@trpc/openapi';

const doc = generateOpenAPIDocument('./src/server/router.ts', {
  exportName: 'AppRouter',
  title: 'My API',
  version: '1.0.0',
});

The generator statically analyses your router's TypeScript types — it never executes your code.

Documentation

Full documentation is available at trpc.io/docs/openapi.

AI Agents

If you use an AI coding agent, install tRPC skills for better code generation:

npx @tanstack/intent@latest install

TODO

• SSE subscriptions
• non-json content types (might already work, needs tests)
• non-nodejs example
• an ai/mcp example
• investigate async generators support (types generate... poorly)
• Document breaking change detection via oasdiff

Maybes

• workaround for needing transformers even cross-ecosystem (some options documented)
• REST translation layer without TrpcEnvelope and with alternative search params formats for get