JSLab
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The jslab CLI

Open files and piped code in JSLab from a terminal with the jslab command, and run them straight away.

jslab is a small command-line tool that opens files, or code piped from another command, in a new JSLab tab.

Install it

Open files in JSLab from a terminal, or pipe code into a new tab and run it.

Choose Help → Install jslab Command… to link the jslab binary inside the app (Contents/Resources/app/bin/jslab) into ~/.local/bin/jslab.

If ~/.local/bin isn’t on your PATH, the message tells you the line to add to your shell profile:

export PATH="$HOME/.local/bin:$PATH"

Once it’s installed, the same menu item reads Uninstall jslab Command…, which removes the link.

Usage

jslab [file ...]                 Open files in new tabs
jslab -                          Read code from stdin into a new tab
jslab --run [file|-]             Open and run immediately
      --runtime bun|browser|browser-node
      --lang ts|js|tsx|jsx       (default: from extension, else settings)
      --cwd <dir>                Set the tab's working directory (default for `-`: current dir)
      --title <title>
jslab --version | --help
Option What it does
--run Runs the code as soon as it opens. Without it, the file only opens.
--runtime The tab’s runtime: bun, browser or browser-node (Browser & Node APIs).
--lang The tab’s language. By default it comes from the file’s extension, or from your settings.
--cwd The tab’s working directory. For jslab -, it defaults to your terminal’s current folder.
--title The tab’s title.

Examples

# Open a file in a new tab
jslab notes.ts

# Run code piped from stdin
echo 'console.log(new Date())' | jslab --run -

# Open a component in the Browser runtime, in the current folder
jslab --runtime browser --cwd . app.tsx

How it works

If JSLab isn’t running, jslab starts it and waits up to 10 seconds for it to be ready. Each call then sends one request over a local socket, jslab.sock in JSLab’s data folder. See Troubleshooting for where that is.

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