> ## 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 callback

> Fired when an event's aggregated trading volume grows by a multiple of `spike_ratio` within a timeframe. Requires `spike_ratio` (> 1.0, e.g. `2.0` fires when volume doubles). Optional `window_secs` sets the observation window in seconds (max 600). Optional `timeframes` and `event_slugs` to narrow scope.



## OpenAPI

````yaml https://api.struct.to/webhookopenapi.json webhook event-volume-spike
openapi: 3.1.0
info:
  title: Polymarket Webhook API
  description: ''
  license:
    name: ''
  version: 1.0.0
servers:
  - url: https://api.struct.to/v1
security: []
tags:
  - name: Webhooks
    description: Webhook subscription management (CRUD operations)
  - name: Webhook Callbacks
    description: Outgoing HTTP calls to your endpoints when subscribed events occur
paths: {}

````