src/hooks/executor.rs

This file runs your hooks: pre-checks with short-circuit semantics, notifications with none. It is where you learn which hook gets to say no.

Key items

You create a HookExecutor with HookExecutor::new(), which starts Headless, then add hooks through with_interactivity(...), with_hook(...), or register(...). Your hook_count() reports how many you installed.

check_pre_tool_use(ctx) -> HookAction lets the first non-Allow win. Under apply_interactivity, Ask downgrades to block in Headless with the message preserved in the reason.

check_pre_compact(ctx) -> CompactResult is abort-first. Instructions accumulate into the context as your hooks run, the last new_instructions wins, and additional_context extends.

Your notify methods run every hook: notify_post_tool_use, notify_post_compact, and notify_run_start plus notify_run_end, each with *_async ready-future wrappers that do no task spawning.

Behavior notes

Your hooks are stored in registration order, append-only, never reordered. Register the same instance twice and it runs twice.

An empty executor returns Allow and a default CompactResult in both interactivity modes.

Your engine consults this file at the exact boundaries: pre-tool before dispatch, where a block becomes a soft error result, and pre-compact before a pass.

Deep dive: Hooks.