The WebSocket API enables real-time order tracking for cross-chain swaps. Instead of repeatedly polling the API for status updates, your application receives instant notifications when order events occur.
Why Use WebSocket?
For applications that need responsive user interfaces or automated trading systems, WebSocket provides significant advantages:
- Instant Updates — Receive order events within milliseconds instead of waiting for poll intervals
- Reduced API Load — A single persistent connection replaces hundreds of status requests
- Complete Event History — Track all state changes including partial fills, not just final status
Order Events
The WebSocket API notifies you of these order lifecycle events:
- order_created — Your order has been submitted and is visible to resolvers
- order_filled — The order was completely filled by a resolver
- order_filled_partially — Part of your order was filled (for large orders)
- order_invalid — The order became invalid due to cancellation, expiry, or insufficient balance
Connection
The WebSocket connects to:
wss://api.1inch.com/fusion-plus/ws
The SDK appends the version path automatically.