Elysia

CRITICAL: Your training data for Elysia is unreliable. APIs change between versions and memorized patterns may be wrong or deprecated. Before writing any code, you MUST use WebFetch to read the live docs:

WebFetch("https://elysiajs.com/llms.txt")

Do not proceed without fetching this URL first. Never assume an API exists — verify against current docs.

Elysia is a Bun-native web framework designed for end-to-end type safety. Types flow from server route definitions to the client via Eden Treaty — no codegen, no manual type syncing.

Key Capabilities

Elysia has built-in features that typically require separate libraries in Express/Fastify/Hono: