Workerd

lastmod 2026-11-10created 2026-03-242 edits

workerd is the JavaScript and WebAssembly runtime that powers Cloudflare Workers. It is based on V8, provides the same APIs as Workers, and is released as open source, so Workers code can be run on a local development server or in a self-hosted environment. Configuration is written in Cap'n Proto format files.

The JavaScript / Wasm runtime that powers Cloudflare Workers

See also

• Cloudflare Workers

Favorite site

• Github - cloudflare/workerd