# elysiajs/elysia

Ergonomic Framework for Humans

Repository: https://github.com/elysiajs/elysia
Canonical: https://ross.abutalabs.com/products/elysia
Homepage: https://elysiajs.com
Language: TypeScript
License: MIT
License Family: permissive
Topics: framework, typescript, bun, web, http, server
Last push: 2026-08-26T21:19:05+00:00

## Health v2 (maintenance only)
Score: 94/100 (v2, computed 2026-09-03T02:39:23.370411+00:00)
- activity 99, release rhythm 87, longevity 97
- inputs: {"age_days": 1368, "days_push": 7, "days_rel": 7, "gap_med": 2.0, "n_releases_24m": 95}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 18975, forks 574 (observed 2026-08-28T04:11:27.307633+00:00)

## What it is
Elysia is a TypeScript backend web framework built for Bun, emphasizing end-to-end type safety, schema-driven validation, and ergonomic developer experience. It generates OpenAPI docs and client types from a single schema source and claims top-tier benchmark performance.

## Use cases
- build a fast REST API in TypeScript on Bun
- get end-to-end type safety between server and client like tRPC
- auto-generate OpenAPI documentation from route schemas
- build realtime apps with WebSockets and server-sent events
- replace Express or Fastify with a faster Bun-native framework
- validate request bodies and infer handler types from one schema

## When to choose
- you use (or are willing to adopt) the Bun runtime
- you want type-safe APIs with minimal boilerplate and great DX
- raw HTTP throughput matters for your service

## When to avoid
- your deployment targets Node.js or Deno exclusively and you can't use Bun
- you need a mature ecosystem of middleware beyond what Elysia plugins cover
- your team is locked into an existing Express/NestJS codebase

## Facets
- artifact type: framework
- maturity: active
- function: web-framework, http-server, routing, websocket, middleware, api-framework
- domain: web-development, backend, apis, developer-tools
- platform: bun, cross-platform
- tags: end-to-end-type-safety, openapi, typebox-validation, eden-rpc, server-sent-events, high-performance, typescript, web-server

## Member repositories
- elysiajs/elysia (main) score 94

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:11:27.307633+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:00:43.057037+00:00, confidence not recorded.
  - readme: https://github.com/elysiajs/elysia (fetched 2026-08-28T04:11:27.307633+00:00, sha 5ea2de9e8ab0)
  - homepage: https://elysiajs.com (fetched 2026-08-29T07:59:21.438436+00:00, sha 2edbd5f54068)
  - site_page: https://elysiajs.com/table-of-content.html (fetched 2026-08-29T07:59:21.447830+00:00, sha 2ddbc1181b5a)
- Data as of 2026-08-30T08:39:29.467469+00:00.