> ## 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.

# Asset price window update callback

> Fired at the start and end of each price candle for tracked crypto assets (BTC, ETH, SOL, XRP, DOGE, BNB, HYPE). Payload includes `update_type` (`"open"` or `"close"`) indicating whether the candle is opening or closing. Use `asset_symbols` to restrict to specific assets. Use `timeframes` to restrict to specific candle sizes — valid values: `"5m"`, `"15m"`, `"1h"`, `"4h"`, `"1d"`, `"24h"`.



## OpenAPI

````yaml https://api.struct.to/webhookopenapi.json webhook asset-price-window-update
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: {}

````