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

# Event Holder Metrics

> Get notified when holder metrics update for an event.

<Note>
  **Event:** `event_holder_metrics` \
  **Endpoint:** `wss://api.struct.to/ws/alerts` \
  **Cost:** 0.025 credits per event
</Note>

Fires when the holder count updates for one of the events you subscribe to, aggregated across every market in that event. The `event_slugs` filter is required: you only receive metrics for the event slugs you name.

## Filters

| Filter        | Type       | Required | Description                    |
| ------------- | ---------- | -------- | ------------------------------ |
| `event_slugs` | `string[]` | Yes      | Event slugs to track (max 500) |

## Subscribe

```json theme={null}
{
  "op": "subscribe",
  "event": "event_holder_metrics",
  "event_slugs": ["2026-us-midterm-elections"]
}
```

## Response

```json theme={null}
{
  "event": "event_holder_metrics",
  "timestamp": 1775913505260,
  "data": {
    "ts": 1713052800,
    "block": 68554321,
    "event_slug": "2026-us-midterm-elections",
    "holder_count": 9120
  }
}
```