Hooks
Automate governance without relying on the model to remember.
In one sentence
Interception points in the agent cycle where custom code runs automatically: before a tool, after an edit, at the end of the turn. They are used for validation, formatting, and blocking prohibited actions, and they automate governance without relying on the model to remember.
Before
Agent is about to execute an action
What it does
Code intercepts and validates
After
Proceeds, is corrected, or is blocked
Example
A hook runs before any sending tool: it scans the text for CPF, address, and school name. If it finds them, it blocks the action and returns the reason. The LGPD rule is enforced by code on every execution, whether or not the model remembers it.
In practice
- Use it for anything that cannot depend on the model remembering: LGPD, limits, format.
- A hook that blocks needs to return the reason; otherwise, the agent will try again the same way.
- Keep the hook fast, because it runs on every execution and, if slow, becomes a bottleneck.
How to make it tangible
Code that runs before or after a tool, validating or blocking the action.
Connects with
Translated from Portuguese with AI assistance.