What does it do?
Lasm compiles ordinary Lean 4 programs ahead of time to WebAssembly. Its npm package includes Lean, Lake, and build tools, so developers can start in a Node, Bun, or Deno environment. During development, saving a file triggers a rebuild and server restart; if a type error occurs, the last successful build keeps running. Examples include a REST API, a server-rendered browser app, and Conduit, which includes proofs. Node builds and edge and browser builds differ in their available thread, file, and socket capabilities.
Key features
- Compile Lean 4 programs ahead of time to WebAssembly
- Build Node servers, edge functions, WASI modules, and browser apps
- Automatically rebuild and restart the server after saving
- Keep the last successful build running when a type error occurs
- Support proofs of properties of Lean code