cancel payload (gRPC) | Hyperliquid API Docs

Decode Hyperliquid `cancel` payloads for order cancellations by ID, returned through Dwellir's read-only L1 gRPC API.

Read-only action reference

Dwellir's Hyperliquid gRPC API returns this decoded action payload through StreamBlocks and GetBlock. It does not submit or execute this action. Submit supported user write actions through Hyperliquid's native POST /exchange endpoint.

The decoded cancel payload records one or more native Hyperliquid order-cancellation requests identified by order ID (oid).

Sample Data

JSON

{
  "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:

Python

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 - New order payloads
cancelByCloid - Cancellations by client order ID
scheduleCancel - Scheduled cancellations

cancel payload - Order Cancellations by ID