Venue System

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Overview

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How it works

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Venue response

{
  "venue": {
    "exchange": "0xA1b2C3...",
    "adapter": "0xD4e5F6..."
  }
}

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Required token approvals

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New trading venues

{
  "venue": {
    "exchange": "0x…",
    "adapter": null,
    "feeModule": "0x…",
    "feeModuleType": "COLLATERAL"
  }
}

1. Approve USDC to venue.feeModule from the wallet that signs orders. A max approval is recommended. Approve once per fee module address. Simple CLOB and NegRisk markets use different fee modules, so always read the address from the market and never hardcode it. The approval is required for every order that is not postOnly, both BUY and SELL. Without it, the API rejects the order with Insufficient collateral allowance for the order fee.
2. Keep your existing approvals. The USDC and Conditional Token approvals to venue.exchange and venue.adapter remain valid, and the EIP-712 domain (verifyingContract = venue.exchange) is unchanged.
3. Sign feeRateBps as 0. Any other value is rejected with FEE_RATE_MISMATCH. Orders on legacy venues keep the current fee rate rules.
4. Keep a little extra USDC. Buy orders need the order amount plus a fee reserve of 5% of it at the standard rate. Sells need no USDC. See how the fee is calculated.

import { erc20Abi, maxUint256 } from 'viem';

const API_URL = 'https://api.limitless.exchange';
const USDC = '0x…'; // USDC token address on Base

const { venue } = await (await fetch(`${API_URL}/markets/${slug}`)).json();
const isNewVenue = venue?.feeModuleType === 'COLLATERAL';

if (isNewVenue) {
  // One-time per fee module address, from the wallet that signs orders
  await walletClient.writeContract({
    address: USDC,
    abi: erc20Abi,
    functionName: 'approve',
    args: [venue.feeModule, maxUint256],
  });
}

// Sign this value. legacyFeeRateBps follows the legacy rules: your
// effectiveFeeRateBps on fee-enabled markets, 0 on fee-disabled markets.
const feeRateBps = isNewVenue ? 0 : legacyFeeRateBps;