BNB Smart Chain (BSC)

import { wrapFetch } from '@dexterai/x402/client';
 
const x402Fetch = wrapFetch(fetch, {
  evmPrivateKey: process.env.EVM_PRIVATE_KEY,
  preferredNetwork: 'eip155:56',
});
 
// BSC payment handled automatically via Permit2
const response = await x402Fetch('https://api.example.com/protected');

// Check allowance
const allowance = await publicClient.readContract({
  address: tokenAddress,
  abi: erc20Abi,
  functionName: "allowance",
  args: [userAddress, "0x3D56A1A196aC81c959A1be21ABC28c173fB063B8"],
});
 
// Approve if needed (~$0.02 BNB, one time)
if (allowance < totalPaymentAmount) {
  await walletClient.writeContract({
    address: tokenAddress,
    abi: erc20Abi,
    functionName: "approve",
    args: ["0x3D56A1A196aC81c959A1be21ABC28c173fB063B8", approvalAmount],
  });
}
 
// Sign the EIP-712 payment (gasless)
const signature = await walletClient.signTypedData({
  domain: { name: "DexterBSCFacilitator", version: "1", chainId: 56n,
    verifyingContract: "0x3D56A1A196aC81c959A1be21ABC28c173fB063B8" },
  types: {
    Payment: [
      { name: "from", type: "address" }, { name: "to", type: "address" },
      { name: "token", type: "address" }, { name: "amount", type: "uint256" },
      { name: "fee", type: "uint256" }, { name: "nonce", type: "uint256" },
      { name: "deadline", type: "uint256" }, { name: "paymentId", type: "bytes32" },
    ],
  },
  primaryType: "Payment",
  message: { from: userAddress, to: merchantAddress, token: tokenAddress,
    amount: paymentAmount, fee: feeAmount, nonce: randomNonce,
    deadline: BigInt(deadlineUnix), paymentId: randomBytes32 },
});
 
// Submit to facilitator (same /verify + /settle as every other chain)

# Returns two kinds: exact (permit2) and exact-approval
curl -s https://x402.dexter.cash/supported | jq '.kinds[] | select(.network == "eip155:56")'