# Developers

SleekTrack has three surfaces for code: the `window.sleekTrack` function on
tracked pages, PHP hooks, and a REST API. Its WP-CLI commands are described
in [CLI](/docs/track/cli.md).

## Sending events

Custom events and their properties are sent from the browser through
`window.sleekTrack`; see [Events and goals](/docs/track/events.md).

## Hooks

SleekTrack fires actions when its data or state changes, so your own code can
react, for example to keep an external system in step:

- Sites: `sleekTrack/site/created`, `sleekTrack/site/updated` and
  `sleekTrack/site/deleted`, from the workspace, the REST API and WP-CLI
- Groups: `sleekTrack/group/created`, `sleekTrack/group/updated` and
  `sleekTrack/group/deleted`
- Networks: `sleekTrack/network/enabled` and `sleekTrack/network/disabled`
- Lifecycle: `sleekTrack/init` at the end of every boot,
  `sleekTrack/activated`, `sleekTrack/activatedNetwork` and
  `sleekTrack/deactivated`, and `sleekTrack/database/tablesCreated` and
  `sleekTrack/database/tablesDropped` for the analytics tables

The `sleekTrack/revenue/baseCurrency` filter sets the headline revenue
currency on a site without WooCommerce or Easy Digital Downloads; see
[Revenue](/docs/track/events.md#revenue).

```php
add_action('sleekTrack/site/created', function (array $site) {
    error_log('Now tracking ' . $site['domain']);
});
```

[Hooks](/docs/track/reference/hooks.md) lists every hook with its arguments.

## REST API

The dashboards read and write everything through the `sleek-track/v1` REST
namespace, and so can your code: sites, groups, statistics and breakdowns,
goals, funnels, annotations, share links, saved views, CSV export, history
import and the collection settings. Every operation needs the
`manage_options` capability, the network operations need
`manage_network_options`, and the operations behind a share link,
`Shares_stats`, `Shares_statsBreakdown` and `Shares_statsRealtime`, are
public and check the link's password themselves. For example, `Sites_stats` returns a site's totals, the
previous period and the timeseries:

```bash
curl -u admin:APPLICATION_PASSWORD \
  'https://example.com/wp-json/sleek-track/v1/sites/1/stats?period=30d'
```

Statistics operations take `period`, `from` and `to` like the dashboard, and
`filters` as a JSON array of `{"key": "...", "value": "..."}` objects. Every
response is wrapped as `{"success": true, "data": ...}`.
[REST operations](/docs/track/reference/rest.md) lists every operation with its
method, path and permission.

The collector itself is not part of the REST API. The tracker posts to the
site's home URL with `?sleek-track=1`, or to `admin-ajax.php` as a fallback;
see [Snippet](/docs/track/snippet.md).