elysia

elysia

Build high-performance Bun apps with Elysia.

Bun-Native Performance

• Built on Bun runtime for fast startup and low latency
• Zero-cost abstractions with compile-time optimizations
• Native Bun file I/O and SQLite support

Eden Treaty

• End-to-end type safety between server and client
• EdenTreaty generates typed client from server instance
• Shared types without code generation

Validation

• Built-in validation via Elysia.t (type system DSL)
• Supports all standard types: string, number, boolean, enum, array
• Custom error messages and validation transforms

WebSocket & File Uploads

• Built-in WebSocket support via app.ws()
• File uploads via @elysiajs/bun form data
• Streaming responses for large payloads

Rate Limiting & Auth

• @elysiajs/rate-limit for request throttling
• JWT auth via @elysiajs/jwt
• Cookie-based sessions with @elysiajs/cookie
• CORS configuration via @elysiajs/cors