GoKawiilLasm lets developers compile Lean 4 code to WebAssembly for Node, edge and browser apps
Lasm is a new toolchain that ahead-of-time compiles standard Lean 4 programs into WebAssembly, letting a single codebase run as a Node server, serverless or edge function, WASI/Fastly module, or browser app. It ships via npm bundling Lean and its Lake build tools, requiring only Node, Bun, or Deno. Its flagship demo, a RealWorld-spec app called Conduit, includes 117 formally proved theorems.