> ## 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 Metrics

> Get notified when an event's aggregated metrics cross a threshold.

<Note>
  **Event:** `event_metrics` \
  **Endpoint:** `wss://api.struct.to/ws/alerts` \
  **Cost:** 0.1 credits per event
</Note>

Get notified when an event's aggregated metrics cross a threshold. Filter by event slugs, volume ranges, or timeframes to receive only the alerts you need.

## Filters

| Filter                      | Type      | Required | Description                                                                    |
| --------------------------- | --------- | -------- | ------------------------------------------------------------------------------ |
| `event_slugs`               | string\[] | No       | Restrict to specific events (max 500)                                          |
| `min_volume_usd`            | number    | No       | Minimum volume in USD                                                          |
| `max_volume_usd`            | number    | No       | Maximum volume in USD                                                          |
| `min_fees`                  | number    | No       | Minimum fees in USD                                                            |
| `min_txns`                  | number    | No       | Minimum transaction count                                                      |
| `min_unique_traders`        | number    | No       | Minimum unique trader count                                                    |
| `timeframes`                | string\[] | No       | Timeframe windows: `1m`, `5m`, `30m`, `1h`, `6h`, `24h`, `7d`, `30d` (max 500) |
| `exclude_shortterm_markets` | boolean   | No       | Exclude short-term markets from results                                        |

## Subscribe

```json theme={null}
{
  "op": "subscribe",
  "event": "event_metrics",
  "min_volume_usd": 5000,
  "timeframes": ["1h", "24h"]
}
```

## Response

<Info>
  **Volume on Polymarket vs. Struct.** Polymarket's UI reports "volume" as notional (the count of shares or contracts traded), which corresponds to `shares_volume` in Struct payloads. `usd_volume` is the dollar value of those trades. Use `shares_volume` to match figures shown on Polymarket and `usd_volume` for true USD throughput.
</Info>

```json theme={null}
{
  "event": "event_metrics",
  "timestamp": 1775913505260,
  "data": {
    "event_slug": "us-presidential-election-2028",
    "timeframe": "1h",
    "volume_usd": 82410.25,
    "shares_volume": 126800.0,
    "builder_usd_volume": 20800.0,
    "builder_shares_volume": 32000.0,
    "fees": 824.10,
    "builder_fees": 208.0,
    "txns": 215,
    "builder_txns": 54,
    "unique_traders": 98,
    "unique_builder_traders": 25
  }
}
```

Each payload includes builder-attributed counterparts for volume, fees, transactions, and unique traders so you can monitor builder-routed activity separately.