What is this?
Elysia is a TypeScript framework for building HTTP servers and APIs. It pitches end-to-end type safety and a polished developer experience, and it is built on the Bun runtime.
Elysia is a TypeScript framework for building HTTP servers and APIs. It pitches end-to-end type safety and a polished developer experience, and it is built on the Bun runtime.Is it a full web framework, or a thin routing library I have to assemble myself?A full framework: routing, cookie handling and URI decoding are built in. Its runtime dependencies are just four small packages — a router (memoirist), a cookie parser, a URI decoder and a type-mirroring helper.
A full framework: routing, cookie handling and URI decoding are built in. Its runtime dependencies are just four small packages — a router (memoirist), a cookie parser, a URI decoder and a type-mirroring helper.How do I add it to a project and get a server running?Install the package with 'bun add elysia' (npm works too), import it and start a server on Bun; the repo's own dev loop is 'bun run --watch example/a.ts'.
Install the package with 'bun add elysia' (npm works too), import it and start a server on Bun; the repo's own dev loop is 'bun run --watch example/a.ts'.Am I locked into Bun, or can I run it on Node.js too?Bun is the intended runtime, but the repo's test suite explicitly runs the framework under Node.js as well — both CommonJS and ESM — so Node projects are covered.
Bun is the intended runtime, but the repo's test suite explicitly runs the framework under Node.js as well — both CommonJS and ESM — so Node projects are covered.Where can I deploy it — does it run outside a regular server, say on Cloudflare Workers?Yes — besides Bun and Node, the repo ships a Cloudflare Workers test setup with generated worker types, so edge deployment on Cloudflare is explicitly tested.
Yes — besides Bun and Node, the repo ships a Cloudflare Workers test setup with generated worker types, so edge deployment on Cloudflare is explicitly tested.What does end-to-end type safety actually get me in day-to-day code?Route definitions and handlers share one type chain, so mismatches between what a route accepts and what it returns surface at compile time. The repo even keeps a dedicated tsc-based type test suite to enforce it.
Route definitions and handlers share one type chain, so mismatches between what a route accepts and what it returns surface at compile time. The repo even keeps a dedicated tsc-based type test suite to enforce it.Is it mature enough to build a production service on, or still experimental?Established rather than experimental: started in December 2022, around 19.2k GitHub stars, MIT-licensed, with GitHub Actions CI over a multi-target test matrix.
Established rather than experimental: started in December 2022, around 19.2k GitHub stars, MIT-licensed, with GitHub Actions CI over a multi-target test matrix.Which topics is it in?developer-experience, type-safe, cloudflare-workers, bun, web-framework, http, rest-api, backend, web-development, performance, framework, npm
developer-experience, type-safe, cloudflare-workers, bun, web-framework, http, rest-api, backend, web-development, performance, framework, npm