Elysia

Elysia is a TypeScript-first REST framework designed for Bun. End-to-end type safety, compile-time optimisation, and a plugin architecture that keeps things composable without the bloat of Express or Fastify.

For Bun projects, it's the natural choice. The performance benchmarks are impressive, but the real win is developer experience — route definitions, validation, and error handling all work with full type inference. We use it for API services where the simplicity of the framework matches the simplicity of the deployment.