> ## Documentation Index
> Fetch the complete documentation index at: https://docs.antigen.sh/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Hooks

Hooks are extension points in a vulnerability's lifecycle. A vulnerability emits an event when its status or assignment changes. A hook receives that event and can start work in response.

Antigen uses hooks for its built-in workflows. You can use the same hooks through the SDK to extend the lifecycle with your own agents and workflows.

## Status changes

A status-change hook receives the previous status and the current status.

When Antigen creates a vulnerability, the previous status is `null` and the current status is `open`. The same event occurs when a vulnerability moves back to `open` after verification finds that the issue remains exploitable. Antigen's triage workflow responds to either event. When the status changes to `remediated`, a verification workflow can respond.

## Assignment changes

An assignment-change hook receives the previous assignee and the current assignee.

For a new assignment, the previous assignee is `null`. A handler can use the event to give the newly assigned agent or person the context they need to act.

## Extend the lifecycle

Antigen registers built-in handlers for triage and remediation. You can register your own handlers through the SDK. For example, you can assign a vulnerability to your coding agent or create a task in your team's tools.