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What is Dome API?

Dome API provides comprehensive access to prediction market data across multiple platforms including Polymarket and Kalshi. Get real-time market prices, historical candlestick data, wallet analytics, order tracking, and cross-platform market matching. Get started with a free API key here.

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What are Websockets?

Dome API provides real-time data streaming through WebSocket connections, allowing you to receive live updates for market prices, trades, orderbook changes, and more without constantly polling the REST API.

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Tier Limits

Subscription and wallet tracking limits vary by tier:
TierSubscriptionsWallets per Subscription
Free25
Dev500500
EnterpriseCustomCustom

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Quick Start

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1. Get Your API Key

Sign up for an account and get your API Key from the dashboard. Hero Light Pn

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2. Connect to the WebSocket

Connect to the Dome API WebSocket endpoint to start receiving real-time data. Below is an example using wscat wscat -c wss://ws.domeapi.io/<API_KEY_GOES_HERE>

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3. WebSocket Actions

Dome API WebSockets support three main actions to manage your real-time data streams:

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Subscribe

Subscribe to channels to start receiving real-time updates. You can filter orders by:
  • User addresses - Track trades from specific wallets or use a wildcard for all trades (Dev tier only)
  • Condition IDs - Track trades for specific market conditions
  • Market slugs - Track all trades within specific markets
{
    "action": "subscribe",
    "platform": "polymarket",
    "version": 1,
    "type": "orders",
    "filters": {
        "users": ["0x6031b6eed1c97e853c6e0f03ad3ce3529351f96d"]
    }
}
Learn more about subscribing →

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Update

Update an existing subscription’s filters without creating a new subscription: 
{
    "action": "update",
    "subscription_id": "sub_k7f5hgr7wy",
    "platform": "polymarket",
    "version": 1,
    "type": "orders",
    "filters": {
        "users": ["0x6031b6eed1c97e853c6e0f03ad3ce3529351f96d"]
    }
}
Learn more about updating subscriptions →

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Unsubscribe

Stop receiving updates from a subscription: 
{
    "action": "unsubscribe",
    "version": 1,
    "subscription_id": "sub_wjhhq8dny2"
}
Learn more about unsubscribing →

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