Cancel Orders (WebSocket)

Cancel one or more existing orders through the WebSocket connection for fastest order management.

Action Result Notifications

This method executes cancellations immediately. Cancellation events are automatically sent via SubAccount Updates Subscription if subscribed.

Endpoint

ws.send() wss://api.synthetix.io/v1/ws/trade

Request

Request Format

{
  "id": "cancel-1",
  "method": "post",
  "params": {
    "action": "cancelOrders",
    "orderIds": ["1948058938469519360", "1948058938469519361"],
    "nonce": 1704067200000,
    "expiresAfter": 1704067300000,
    "signature": {
      "v": 28,
      "r": "0x1234567890ABCDEF1234567890ABCDEF1234567890ABCDEF1234567890ABCDEF",
      "s": "0xABCDEF1234567890ABCDEF1234567890ABCDEF1234567890ABCDEF1234567890"
    }
  }
}

Parameters

Request Parameters

Params Object

Response Format

Success Response

{
  "id": "cancel-1",
  "status": 200,
  "result": [
    {
      "canceled": {
        "orderId": "1948058938469519360"
      }
    },
    {
      "canceled": {
        "orderId": "1948058938469519361"
      }
    }
  ]
}

Error Response

{
  "id": "cancel-1",
  "status": 404,
  "result": null,
  "error": {
    "code": 404,
    "message": "Order not found or does not belong to this subaccount"
  }
}

Implementation Example

// Cancel single order
const cancelRequest = {
  id: "cancel-1",
  method: "post",
  params: {
    action: "cancelOrders",
    orderIds: ["1948058938469519360"],
    nonce: Date.now(),
    expiresAfter: Date.now() + 30000,
    signature: await signCancelMessage(...)
  }
};
 
ws.send(JSON.stringify(cancelRequest));
 
// Cancel multiple orders
const cancelMultiple = {
  id: "cancel-2",
  method: "post",
  params: {
    action: "cancelOrders",
    orderIds: ["1948058938469519360", "1948058938469519361"],
    nonce: Date.now(),
    expiresAfter: Date.now() + 30000,
    signature: await signCancelMessage(...)
  }
};
 
ws.send(JSON.stringify(cancelMultiple));

Implementation Notes

• Cancellation requests must include at least one order ID
• Order IDs must belong to the authenticated subaccount
• Authentication timestamps must be monotonically increasing per subaccount
• EIP-712 domain separator must use "Synthetix" for WebSocket endpoints

Cancellation Behavior

• Only OPEN and PARTIALLY_FILLED orders can be cancelled
• Filled portions of partially filled orders remain executed
• Cancellation is immediate upon validation
• Freed margin becomes available instantly

Signing

All trading methods are signed using EIP-712. Each successful trading request will contain:

• A piece of structured data that includes the sender address
• A signature of the hash of that structured data, signed by the sender

For detailed information on EIP-712 signing, see EIP-712 Signing.

Nonce Management

The nonce system prevents replay attacks and ensures order uniqueness:

• Use current timestamp in milliseconds as nonce
• Each nonce must be greater than the previous one
• Recommended: Use Date.now() or equivalent
• If nonce conflicts occur, increment by 1 and retry

Next Steps

• Modify Order - Order modification via WebSocket
• Cancel All Orders - Emergency cancellation
• REST Alternative - REST API comparison