POST /cancel-order

This endpoint builds a cancellation transaction for an existing limit order. The returned payload must be signed and submitted to the blockchain by the caller to complete the cancellation.

TypeScript Types: Generate types for this API with a single command. See Type Generation.

API Reference: For detailed schema definitions and interactive testing, see the API Reference.

Request

Endpoint

POST /cancel-order

Headers

Content-Type: application/json
x-api-key: YOUR_API_KEY

Body Parameters

Field	Type	Required	Description
`orderId`	`string`	Yes	The ID of the limit order to cancel
`chain`	`Chain`	Yes	The chain where the order was placed

Example Request

import type { components } from './m0-swap'; // From type generation
 
type CancelOrderResponse = components['schemas']['CancelOrderResponse'];
 
const response = await fetch('https://gateway.m0.xyz/v1/orchestration/cancel-order', {
  method: 'POST',
  headers: {
    'Content-Type': 'application/json',
    'x-api-key': YOUR_API_KEY,
  },
  body: JSON.stringify({
    orderId: '0xabc123...', // The limit order ID
    chain: 'Ethereum',
  }),
});
 
if (!response.ok) {
  const error = await response.text();
  throw new Error(`Cancel order failed: ${error}`);
}
 
const result: CancelOrderResponse = await response.json();

Response

Success Response (200)

Returns a CancelOrderResponse object containing the transaction payload to submit on-chain to complete the cancellation.

import type { components } from './m0-swap';
 
type CancelOrderResponse = components['schemas']['CancelOrderResponse'];

Response Fields

Field	Type	Description
`orderId`	`string`	The ID of the order being cancelled
`chain`	`Chain`	The chain where the cancellation transaction must be sent
`payload`	`TransactionPayload`	The signed transaction data to submit to cancel the order

The payload field follows the same TransactionPayload structure as quote payloads — either an EvmPayload or SvmPayload depending on the chain. See the Quote docs for payload execution examples.

Error Responses

Status	Description
`404`	Order not found — the `orderId` does not exist on the specified `chain`
`409`	Order cannot be cancelled — it may already be filled, expired, or cancelled
`500`	Internal server error

Example Response

{
  "orderId": "0xabc123...",
  "chain": "Ethereum",
  "payload": {
    "type": "evm",
    "chain": "Ethereum",
    "chainId": 1,
    "to": "0x1234567890abcdef...",
    "data": "0xabcdef...",
    "value": "0"
  }
}

Executing the Cancellation

Once you have the response, submit the payload to the blockchain to complete the cancellation:

import { createWalletClient, http } from 'viem';
import { mainnet } from 'viem/chains';
import type { components } from './m0-swap';
 
type EvmPayload = components['schemas']['EvmPayload'];
 
async function executeCancelOrder(payload: EvmPayload, account: `0x${string}`) {
  const client = createWalletClient({
    chain: mainnet,
    transport: http(),
    account,
  });
 
  const hash = await client.sendTransaction({
    to: payload.to as `0x${string}`,
    data: payload.data as `0x${string}`,
    value: BigInt(payload.value),
  });
 
  return hash;
}

Notes

Only the original order creator can cancel a limit order
A 409 response means the order is in a terminal state (filled, expired, or already cancelled) and no action is needed
The cancellation is not final until the returned transaction payload is submitted and confirmed on-chain