Hooks

Purpose

Enforce a rule deterministically rather than asking the model to remember it. A hook runs every time, regardless of the model's attention, its context, or its mood — which is exactly what a rule requires.

When to Use

• A rule must hold every time: formatting, a forbidden command, a required check.
• The agent keeps forgetting an instruction despite it being in the instructions.
• Automating a step that should happen around every edit or command.
• Blocking a dangerous action before it executes.

Capabilities

• Lifecycle events: before and after a tool call, on session start, on stop.
• Deterministic enforcement: formatting, linting, blocking.
• Injecting context at the right moment.
• Notification and logging.