> ## 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 Volume Spike

> Get notified when an event's aggregated volume exceeds its baseline by a configured ratio.

<Note>
  **Event:** `event_volume_spike` \
  **Endpoint:** `wss://api.struct.to/ws/alerts` \
  **Cost:** 0.2 credits per event
</Note>

Get notified when an event's aggregated volume exceeds its baseline by a configured ratio. The `spike_ratio` filter is required and defines the volume multiplier threshold.

## Filters

| Filter                      | Type      | Required | Description                                                                    |
| --------------------------- | --------- | -------- | ------------------------------------------------------------------------------ |
| `spike_ratio`               | number    | Yes      | Volume multiplier threshold, must be greater than 1.0 (e.g. 2.0 = 2x baseline) |
| `event_slugs`               | string\[] | No       | Restrict to specific events (max 500)                                          |
| `timeframes`                | string\[] | No       | Timeframe windows: `1m`, `5m`, `30m`, `1h`, `6h`, `24h`, `7d`, `30d` (max 500) |
| `window_secs`               | number    | No       | Window reset interval in seconds (1-600)                                       |
| `exclude_shortterm_markets` | boolean   | No       | Exclude short-term markets from results                                        |

## Subscribe

```json theme={null}
{
  "op": "subscribe",
  "event": "event_volume_spike",
  "spike_ratio": 3.0,
  "timeframes": ["1h"]
}
```

## Response

```json theme={null}
{
  "event": "event_volume_spike",
  "timestamp": 1775913505260,
  "data": {
    "event_slug": "us-presidential-election-2028",
    "event_title": "US Presidential Election 2028",
    "image_url": "https://polymarket-upload.s3.us-east-2.amazonaws.com/us-presidential-election-2028.png",
    "timeframe": "1h",
    "current_volume_usd": 156000.00,
    "snapshot_volume_usd": 48000.00,
    "delta_volume_usd": 108000.00,
    "spike_pct": 225.00,
    "txns": 412,
    "fees": 1560.00
  }
}
```