Just is a simple, and modern runtime for JavaScript that uses V8 and is built in Rust.
- Use your preferred import style. Local, web, package.
- Secure by default. No file, network, or environment access, unless explicitly enabled.
- Useful and extensive built-in utilities.
- Includes a set of standard modules for Just.
Shell (Mac, Linux):
curl -fsSL https://justjs.dev/install.sh | sh
PowerShell (Windows):
irm https://justjs.dev/install.ps1 | iex
Homebrew (Mac):
brew install justjs
Chocolatey (Windows):
choco install justjs
Scoop (Windows):
scoop install justjs
Build and install from source using Cargo:
cargo install justjs --locked
Try running a simple program:
$ just run https://justjs.dev/r/std/examples/welcome.js
# or the direct source link
$ just run https://r.justjs.dev/source/std/0.0.4/examples/welcome.js
Or a more complex one:
import { cmd } from 'just/sys';
import { random } from 'just/crypto';
import { Database } from 'just/db:sqlite';
const db = new Database('db_name');
db.create('versions', 'id text primary key, version text');
await cmd.spawn('just -v').then((output) => {
db.insert('versions', { id: random.secure(), version: output });
});
console.json(db.query('versions', "where version = '%s'".format(cmd.exec('just -v'))), true);
db.delete('versions', '');
Just package registry can be located here (api).
You can find a deeper introduction, examples, and environment setup guides in the docs.
The complete API reference is available at the runtime documentation.