Ts.ED

Ts.ED is a TypeScript framework for building APIs on Node.js. You write classes with decorators for routes, validation, and dependency injection, and it runs them on Express by default, or Koa, Fastify, or serverless. JSON Schema and OpenAPI sit at the core, so your validation and your API docs come from the same decorators. MIT and free.

Nothing to host beyond your own app. Version 8 needs Node 20.11 or later and is ESM only, so CommonJS projects have a migration ahead. Bun works as a runtime. The integration list is long: Prisma, TypeORM, Mongoose, MikroORM, GraphQL, Socket.io, BullMQ, Temporal, Stripe, Passport, and an OIDC provider. Keep every @tsed package on the same version or things break.

Free at every size. The honest comparison is nestjs/nest, which does the same decorator and dependency injection style with a far larger community and paid enterprise support. Pick Ts.ED for schema-first APIs on plain Express without Nest's Angular-style module system. For a team hiring Node developers, Nest is the safer bet.

The catch is bus factor. One maintainer wrote the overwhelming majority of the commits. Some features only work on Express: Passport is Express only, and Fastify has documented gaps. The docs also describe premium plugins behind a $14/mo GitHub sponsorship, though several of those packages now sit on public npm under MIT.