Jac

v0.1.0 · by Jaseci Labs · added 3 November 2026

Jac language support.

LanguagesLanguage servers

How to install

With Forge Super installed, the button above opens the app on this extension, where you press Install. Nothing is installed until you do.

You can also open the Extensions panel in the app and search for Jac. The extension's id is jac.

Don't have Forge Super yet? Download it here.

From the extension's repository, written by its authors and not by Mentenaz. See the source.

Jac language support for Zed.

Install the jac CLI and ensure it is on your PATH:

pip install jaclang

Zed will automatically start jac lsp for .jac files.

You can override the language server binary or arguments in your Zed settings:

{
  "lsp": {
    "jac-lsp": {
      "binary": {
        "path": "/path/to/jac",
        "arguments": ["lsp"]
      }
    }
  }
}

Any settings placed under lsp.jac-lsp.settings are forwarded to the language server as workspace configuration.

Build the extension as a WebAssembly module:

rustup target add wasm32-wasip2
cargo build --target wasm32-wasip2

Then open Zed, run the "zed: extensions" command, click Install Dev Extension, and select this directory.

extension.toml — extension manifest and language/grammar declarations
Cargo.toml / src/jac.rs — Rust extension entry point that launches jac lsp
languages/jac/ — language configuration and Tree-sitter highlights