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

# list_event_types

> Distinct event names in this space with first/last seen dates and a count over a lookback window.

Returns the empirical list of conversion event names the space has actually received — distinct from [`list_custom_events`](/mcp/tools/list-custom-events) which lists *configured* slots (some of which may be empty).

## When to use

* "What events am I tracking?"
* Before composing a `query_events_aggregated` call when you're not sure which events have data.

## Parameters

| Parameter       | Type    | Required | Description                                           |
| --------------- | ------- | -------- | ----------------------------------------------------- |
| `lookback_days` | integer | No       | How many days of history to scan (1–365, default 30). |
| `format`        | string  | No       | `csv` (default), `json`, or `yaml`.                   |

## Output

```csv theme={null}
event_name,label,first_seen,last_seen,count
purchase,purchase,2025-08-12 14:22:00,2026-05-14 23:51:00,28411
custom_event_2,Deal Created,2025-09-04 09:13:00,2026-05-14 19:02:00,892
lead_generated,lead_generated,2025-08-12 14:22:00,2026-05-14 23:51:00,4124
```

`label` is the configured human-readable name for `custom_event_*` slots; otherwise it's the canonical event slug.