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POST
/
2
/
perp
/
payloads
/
cancel-order
Build cancel-order payload
curl --request POST \
  --url https://demo-api.mobula.io/api/2/perp/payloads/cancel-order \
  --header 'Content-Type: application/json' \
  --data '
{
  "timestamp": 123,
  "signature": "<string>",
  "chainId": "<string>",
  "orderIndex": "<string>",
  "marketId": "<string>"
}
'
{
  "success": true,
  "data": {
    "action": "<string>",
    "dex": "<string>",
    "chainId": "<string>",
    "payloadStr": "<string>",
    "marketId": "<string>"
  }
}
Lighter requires the wallet to be a registered account before any trade/withdraw action.If the EOA has never deposited on Lighter, this endpoint will fail. First-time setup is a two-step prerequisite:
  1. Deposit ≥ 5 USDC via /2/perp/payloads/deposit → Lighter creates an accountIndex on-chain once the bridge settles. (5 USDC is a Lighter requirement, not a Mobula limit.)
  2. Provision API key + auth token via /2/perp/payloads/create-account using that accountIndex.
Read the Build Create-Account Payload page for the full setup flow including how to discover the accountIndex after a deposit.
Builds the payload to cancel an unfilled order. For Gains, orderType distinguishes pending limit orders (order) from TP/SL legs (tp, sl) attached to an open trade.

​
Request Body

​
dex
string
required
gains or lighter.
​
chainId
string
required
Chain of the order.
​
orderIndex
string
required
Order index as a positive integer string (regex ^\d+$). Obtainable from /2/wallet/perp/orders.
​
marketId
string
Mobula market identifier. Required by Lighter.
​
orderType
string
Gains only. One of order, tp, sl. Omit for Lighter.

​
Authentication

Every /2/perp/payloads/<action> endpoint verifies the caller by requiring two extra fields in the request body alongside the action parameters:
​
timestamp
number
required
Unix timestamp in milliseconds. Must be within 30 seconds of server time. Older timestamps are rejected to prevent replay.
​
signature
string
required
Hex signature (EIP-191 personal_sign) of the message `${endpoint}-${timestamp}`, where endpoint is the path of this endpoint without the leading slash (e.g., for this page: api/2/perp/payloads/<this-action>). The recovered signer address becomes the user for the request. Single-use — replay returns 403 signature already used.
// Replace `<action>` with the action of THIS page (e.g. create-account, deposit, …)
const endpoint = 'api/2/perp/payloads/<action>';
const timestamp = Date.now();
const signature = await wallet.signMessage(`${endpoint}-${timestamp}`);

await fetch(`https://api.mobula.io/${endpoint}`, {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    timestamp,
    signature,
    // ...action-specific fields below
  }),
});

​
Authentication errors

Statusmessage
403timestamp expired — timestamp older than 30s
403signature already used — replay attempt
400zod validation failed — timestamp/signature shape invalid

​
Response envelope

Every /2/perp/payloads/<action> endpoint returns the same envelope shape. You pass these fields verbatim into POST /2/perp/execute-v2 to execute the action.
Top-level shape. Successful (2xx) responses return { data: { ... } }. A success: true flag is only present inside the body of execute-v2’s response, not on the payload-build endpoints. Parse defensively: read body.data, then check for the action-specific fields you need (e.g. data.payloadStr).
​
data
object

​
Endpoint-specific errors

Statusmessage
400cancel-order payload generation failed — order not found or DEX refusal

​
Full flow — cancel an order end-to-end

Single example covering both DEXes (Lighter offchain-api, Gains evm-tx). The flow branches on data.transport. 
import { ethers } from 'ethers';

// 1. Auth-sign + fetch the cancel-order payload
const endpoint = 'api/2/perp/payloads/cancel-order';
const ts = Date.now();
const authSig = await wallet.signMessage(`${endpoint}-${ts}`);

const { data } = await fetch(`https://api.mobula.io/${endpoint}`, {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    timestamp: ts,
    signature: authSig,
    dex: 'lighter',                  // or 'gains'
    chainId: 'lighter:301',          // or 'evm:42161'
    marketId: 'lighter-btc-usd',     // Lighter requires marketId
    orderIndex: '42',
    // orderType: 'order',           // Gains only: 'order' | 'tp' | 'sl'
  }),
}).then(r => r.json());

// 2. Branch on transport
let signedTx;
const finalPayloadStr = data.payloadStr;

if (data.transport === 'evm-tx') {
  // Gains
  const txData = JSON.parse(data.payloadStr).payload.data;
  const provider = new ethers.JsonRpcProvider(rpcUrlFor(txData.chainId));
  const feeData = await provider.getFeeData();

  const baseTx = {
    to: txData.to,
    data: txData.callData,
    value: txData.value ? BigInt(txData.value) : 0n,
    from: wallet.address,
    chainId: txData.chainId,
    nonce: txData.nonce ?? await provider.getTransactionCount(wallet.address),
  };
  const gasLimit = txData.gas ? BigInt(txData.gas) : await provider.estimateGas(baseTx);

  signedTx = await wallet.signTransaction({
    ...baseTx, gasLimit,
    maxFeePerGas: txData.maxFeePerGas ? BigInt(txData.maxFeePerGas) : feeData.maxFeePerGas,
    maxPriorityFeePerGas: txData.maxPriorityFeePerGas ? BigInt(txData.maxPriorityFeePerGas) : feeData.maxPriorityFeePerGas,
    type: 2,
  });
}

// 3. Sign + submit execute-v2
const execTs = Date.now();
const execSig = await wallet.signMessage(
  `api/2/perp/execute-v2-${execTs}-${finalPayloadStr}`,
);

const execRes = await fetch('https://api.mobula.io/api/2/perp/execute-v2', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    action: data.action,
    dex: data.dex,
    chainId: data.chainId,
    transport: data.transport,
    payloadStr: finalPayloadStr,
    timestamp: execTs,
    signature: execSig,
    ...(signedTx && { signedTx }),
  }),
}).then(r => r.json());

Body

application/json
​
timestamp
number
required
​
signature
string
required
​
dex
enum<string>
required
Available options:
gains,
lighter
​
chainId
string
required
​
orderIndex
string
required

Positive integer string (regex ^\d+$).

​
marketId
string

Required by Lighter.

​
orderType
enum<string>

Gains only. Omit for Lighter.

Available options:
order,
tp,
sl

Response

200 - application/json

Canonical payload envelope

​
success
boolean
required
​
data
object
required