Tutorial: hooks you can poke

Block your first command in the browser, then graduate to the real engine.

Write a hook, type a command at it, watch the verdict. Every widget on these pages runs a JavaScript port of capt-hook’s dispatch — and every preset button is a row in a parity test, so what the widget answers is what capt-hook test answers. When a command uses shell features the port doesn’t model (substitution, heredocs), the widget says so instead of guessing.

Try it — this is the hook you’ll build on the next page:

Six short stops, each one interaction and one idea:

1. Your first block: one line guards a whole command family
2. Precision with Runs: recall vs precision, and why you want both ends
3. Conditions compose: AND, veto, and the guard that ignores reads
4. Walk the command: when a regex can’t decide
5. Stop gates: gate the session, not the tool call
6. Test it, then ship it: the same cases, as inline tests

Fifteen minutes end to end. When you’re done, uvx capt-hook init gives you the real thing.