
Fern: Docs, SDKs, and CLIs for your API
Start with OpenAPI. Generate SDKs in multiple languages, interactive API documentation, and an agent-first CLI.
Backend developers building TypeScript APIs who want automated, type‑safe OpenAPI documentation without writing extra annotations
Elysia now supports OpenAPI Type Gen, a powerful tool that automatically generates OpenAPI documentation from your Elysia routes and types without any manual annotation