Community

Lumen is developed in the open on GitHub. Everything below is a public repository or issue tracker; there is no mailing list to join first.

The compiler

lumen-lang-org/lumen: the compiler, standard library, playground service and this website. Star it to follow releases.

Issues

Bug reports, feature requests and questions. Search first; a short repro gets a fix fastest.

Releases

Every release ships binaries for macOS and Linux (x86_64 and arm64) and a Windows zip, with notes on what changed.

Packages: std-contrib

The curated package catalog. Each package is plain Lumen with tests, imported by URL.

Roadmap

What is not there yet and why, module by module. Comment on an issue if one of these blocks you.

Lumen on npm

Libraries written in Lumen ship as zero-dependency wasm packages. @lumen-lang/markdown is the first.

Report a bug

Open an issue with the smallest .ts file that shows the problem, the command you ran, the full output, and the compiler version from lumen version. If lumen check passes but lumen compile fails, say so: that pair is always a compiler bug.

lumen version
lumen check repro.ts
lumen compile repro.ts

Contribute a package

Packages live in std-contrib, one directory each. The rules are short: current language only (it must compile with the released lumen), statically typed, tested with inline test blocks, self-contained, and focused on one concern.

packages/
  <name>/
    <name>.ts      # the source, with test "…" { expect(…); } blocks
    README.md      # what it does, the public functions, a usage snippet
index.json         # add { "name", "version", "summary", "path" }

Check it locally with lumen test packages/<name>/<name>.ts; CI runs the same command on every package, and the package's page on this site is generated from its README. The full guide is CONTRIBUTING.md.

Contribute to the compiler

The compiler is written in Zig. Each feature lands as a spec folder under specs/ with a plan and tasks, then an implementation slice, then conformance cases. Read CLAUDE.md and docs/CODEMAP.md in the repository for the pipeline layout and the project's working rules, and open an issue before a large change so the design can be agreed first.