Create a session for one-click trading without requiring signatures for each order.

Once a session is created, you can use the returned sessionHash in the x-one-click header for subsequent trading requests without providing signatures for each individual order.

Security: The session is bound to the user address provided during creation. All subsequent one-click trading requests must use the same address as the maker (for limit orders, cancellations) or taker (for market/combo orders). Requests from a different address will be rejected with ONE_CT_USER_MISMATCH.

EIP-712 Signature Example (TypeScript)

import { parseUnits } from 'viem';
import { privateKeyToAccount } from 'viem/accounts';

// Domain parameters for EIP-712 signature
const EIP712Domain = {
  chainId: 421614, // Arbitrum Sepolia (use 42161 for Arbitrum One mainnet)
  name: 'Premia',
  verifyingContract: '0x...' // ClearingHouseProxy address from deployment
  version: '1'
};

// Type definition for one-click session
const OneClickSignature = [
  { name: 'deadline', type: 'uint256' },
  { name: 'user', type: 'address' },
  { name: 'bindToIp', type: 'bool' }
];

// Example session data
const sessionData = {
  user: '0xYourWalletAddress', // Your Ethereum address
  bind_to_ip: true // Optional: bind session to IP address (defaults to true)
};

// Calculate deadline (5 minutes from now)
const deadline = Math.floor(Date.now() / 1000) + 300;

// Setup wallet
const account = privateKeyToAccount('0xYourPrivateKey');

// Sign the typed data
const signature = await account.signTypedData({
  domain: EIP712Domain,
  types: { OneClickSignature },
  primaryType: 'OneClickSignature',
  message: {
    deadline,
    user: sessionData.user,
    bindToIp: sessionData.bind_to_ip
  }
});

// Final request payload
const requestPayload = {
  ...sessionData,
  signature,
  signature_deadline: deadline
};

// Create session
const response = await fetch(`${BASE_URL}/session`, {
  method: 'POST',
  headers: {
    'x-apikey': API_KEY,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify(requestPayload)
});

const { sessionHash } = await response.json();

// Use session for trading
const orderResponse = await fetch(`${BASE_URL}/limit`, {
  method: 'POST',
  headers: {
    'x-apikey': API_KEY,
    'x-one-click': sessionHash,
    'Content-Type': 'application/json'
  },
  body: JSON.stringify(orders) // No signature required
});