JSLab launch-day FAQ, answered from the docs

JSLab feature notes: one docs page, explained. Today: the questions we expect on launch day, each answered from the docs.

JSLab, a fast, native JavaScript & TypeScript scratchpad for macOS, launches tomorrow. Here are the questions we expect, with the docs' answers.

Which Macs does it run on?

Apple Silicon Macs, on macOS 14 or later. No Intel Macs, no Windows, no Linux, no web version. It needs macOS 14 because license verification uses WebKit's Ed25519 support, which macOS 13 lacks. (Install)

Do I need an account?

No. The trial starts with no signup, and buying doesn't create an account either. (Free trial and license)

Is there a trial?

Yes: 14 days, starting the first time you open the app. Every feature works during the trial exactly as it will with a key. If the trial ends, running code pauses; opening, editing and saving keep working, so nothing you've written is locked away.

Does my code leave my Mac?

Your code runs locally. JSLab has no telemetry, no analytics and no crash reporting. The one feature that sends code anywhere is Ask AI, and only to the provider you choose: with Ollama at its standard local address, nothing leaves your Mac. With OpenAI, Anthropic or Gemini, requests go straight from your Mac to them, with your own key, stored in the macOS Keychain. (AI providers and keys)

Does it run TypeScript? npm packages?

Yes, and yes. Types are checked in the editor and stripped when the code runs. ⌘I installs any npm package once, for every tab, with types and autocomplete. (npm packages)

What if my code hangs?

⇧⌘R stops a run; ⌥⌘R kills it. Endless loops are stopped after 2,000 iterations by default. Each run is its own process, so a crash never takes JSLab down. If a tab hangs every time JSLab opens, hold Shift while launching for Safe Mode. (The editor)

How do updates work?

JSLab checks for signed updates about once an hour, fetches them in the background and asks you to restart. Nothing installs while you're working, and an update that can't be verified is never installed. (Updates)

Where's my data?

In one folder: ~/Library/Application Support/dev.jslab.app/<channel>/. Settings, session, snippets, keybindings and imported themes are all plain files there. API keys aren't: they're in your Keychain. Open Data Folder in the command palette takes you there. (Troubleshooting)

Can I bring my VS Code theme?

Yes. Themes → Import VS Code Theme… takes a .json or .vsix. (Themes)

Where do I start?

Open a tab and type. Then Your first tab, or Help → Learning & Tips inside the app.

JSLab launches tomorrow, Nov 15. All the docs: https://js-lab.app/docs