cancel

Cancel one or more existing orders by their order ID (oid). This action removes orders from the order book before they can be filled.

Sample Data#

{
  "signature": {
    "r": "0xb7233b2b2b0cf0eb161f86319be9a86c197f860dbcbe4d4f189e5fa757137c89",
    "s": "0x65e5d0ffd58b0bf7ed168a8d1a9b6f8df6050c7acf24db588fb62f9390e9a2c3",
    "v": 27
  },
  "action": {
    "type": "cancel",
    "cancels": [
      {
        "a": 0,
        "o": 291379970288
      }
    ]
  },
  "nonce": 1768146913376
}

View this transaction on Hypurrscan →

Field Reference#

Action Fields#

Field	Type	Description
`type`	string	Always `"cancel"`
`cancels`	array	Array of cancel requests

Cancel Object Fields#

Field	Type	Description
`a`	number	Asset index of the order to cancel
`o`	number	Order ID (oid) to cancel

Optional Fields#

Field	Type	Description
`vaultAddress`	string	Vault address if cancelling vault orders

Use Cases#

Order Management Systems#

Track cancellation activity to understand order lifecycle and fill rates:

def process_cancel_action(action):
    for cancel in action.get('cancels', []):
        asset = cancel['a']
        order_id = cancel['o']

        print(f"Order cancelled: asset={asset}, oid={order_id}")

Risk Management#

Monitor cancellation patterns to detect:

High cancellation rates (potential spoofing)
Emergency position exits
Market maker quote updates

Market Making Analytics#

Analyze the ratio of order placements to cancellations to understand market maker behavior and quote refresh rates.

order - Submit new orders
cancelByCloid - Cancel by client order ID
scheduleCancel - Schedule future cancellation