Limits

All of them deliberate.

What a Script cannot do

• Touch the machine. No filesystem access, no process control, no shelling out, no AppleScript. Only Effects.
• Use @external. Zero FFI is a measured property of the design, and it is what makes starkit.gleam the whole interface.
• Run another Script, or reach into one. import scripts/other is not a supported shape.
• Outlive 5 seconds. A Script still running then is killed and the bar says so. A fetch that never returns is what that deadline is for.
• Write to stdout. stdout is the protocol: io.println lands in front of the JSON reply and earns you Starkit could not read what "x" answered. echo and io.println_error go to stderr and are safe, which is how you print while debugging.
• Keep anything between runs. A fresh bun per run, and nothing survives it. No caches, no files on the side.
• Carry configuration outside its Manifest. There is no config file and no per-Script key binding; the only key binding in Starkit summons the bar.
• Use OTP, actors, or an Erlang-only Hex package. The target is JavaScript.

Crashing

panic, todo and an unhandled crash all become a Refusal naming the Script, with the stack trace as the detail, and no Effect is performed: the list goes out only once run has returned the whole of it.

Once it has, the Shelf performs the Effects in order and there is no way back. clean guards against Killing Starkit for exactly that reason, since a Kill aimed at itself would end the process partway down its own list.

Limits of the app itself

• The chord is ⌃⌘K and cannot be changed. It races Script Kit, Raycast and Alfred, and the loser registers nothing without saying so.
• There is no preferences window, no theming, and no per-Script configuration outside its own manifest.
• Effects go out and nothing comes back, so no Script can stop and offer you a list to choose from.

When four words are not enough

Adding an Effect or a Context slice is a design decision, and the smallness of the Vocabulary is the property being defended — so the bar for a new word is several Scripts needing it and not one. The same goes for a permission beyond Accessibility, and for a new dependency.

Ask before adding any of them, and update the Vocabulary in the Starkit repo’s CONTEXT.md in the same change that adds to it.