> For the complete documentation index, see [llms.txt](https://attr.sygnal.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://attr.sygnal.com/overview/technical-notes-and-goals/callback-handlers.md).

# Callback Handlers

SA5 uses callbacks for two purposes;

1. Specifying configuration options, for modules which have them 
2. Notifying custom code handlers of state changes that the site owner may want to specially handle 

An example callback; 

```
<script>
window.sa5 = window.sa5 || [];
window.sa5.push(['getMembershipRoutingConfig', 
  (config) => {
  
    // ... your custom code here ... 

    return config;
  }]); 
</script>
```

## Defined Callbacks

<table><thead><tr><th width="284.3333333333333">Callback Name</th><th width="153">Module</th><th>Use</th></tr></thead><tbody><tr><td>getMembershipRoutingConfig</td><td>Memberships</td><td><a href="/pages/qJhFuSJm4MeWvoG2XtOH">Configuration</a></td></tr><tr><td>userInfoChanged</td><td>Memberships</td><td><a href="/pages/i1aP9XW45cKdNk07CpwV">Event Notification</a> when new user information is loaded</td></tr><tr><td>breakpointChanged</td><td>HTML</td><td><a href="/pages/AM2IVshU3PVQTTA5Phkr">Event Notification</a> on a breakpoint change</td></tr></tbody></table>