crosschain-payments.mdx

title	Crosschain Payments
description	Multi-network payment routing with automatic bridging and optimization

Overview

Crosschain payments allow users to pay a request using a stablecoin from a different blockchain network than the one specified on the request. For example, a payer can pay a request for USDC on Base using USDT from their Optimism wallet.

Benefits

• Flexibility: Payers can pay with their preferred currency.
• Cost-Effective: Automated routing balances cost and speed.
• Time-Saving: Payers don't need to swap or bridge tokens manually.
• Simplified UX: Payment settlement requires only 1 or 2 signatures from the payer.

Crosschain Payments Supported Chains and Currencies

For crosschain (and samechain) payments, the Request Network API supports 12 stablecoins: USDC, USDT, and DAI on 4 chains (Ethereum, Arbitrum One, Base, OP Mainnet).

Crosschain Payments Supported Chains

Crosschain payments are supported on the following blockchain networks:

• Ethereum
• Arbitrum One
• Base
• OP Mainnet

Crosschain Payments Supported Currencies

Crosschain payments work only with mainnet funds (real money). Test networks are not supported.

The following stablecoins are supported for crosschain payments on both the sending and receiving networks:

• USDC
• USDT
• DAI

How It Works

To enable crosschain payments, the request must be created with:

• paymentCurrency in the supported stablecoins and supported networks
• amount greater than 1 (crosschain execution under 1 stablecoin is not allowed)

Create the request via POST /v2/request.

Fetch possible routes with [GET /v2/request/{requestId}/routes](https://api.request.network/open-api/#tag/v2request/GET/v2/request/{requestId}/routes). The API returns routes based on payer balances.

The API ranks routes by:

• transaction fees
• processing speed

Each route includes fee estimates and breakdowns:

1. Gas fees for transfer/approval/execution on the processor side
2. Service fees for crosschain infrastructure

For tokens that do not support EIP-2612, payer approval gas is paid directly by the payer and is not included in route total fees.

The API may also return samechain routes when payer funds are on the same chain as paymentCurrency.

Once a route is selected, fetch unsigned payloads using [GET /v2/request/{requestId}/pay](https://api.request.network/open-api/#tag/v2request/GET/v2/request/{requestId}/pay).

• For crosschain routes: returns payment intent + approval payload (permit/calldata)
• For direct samechain routes: returns payment calldata and approval data only when needed

Sign the returned payloads with the payer wallet. Approval handling depends on EIP-2612 support.

import { ethers } from "ethers";

const ethersProvider = new ethers.providers.Web3Provider(
  walletProvider as ethers.providers.ExternalProvider,
);
const signer = await ethersProvider.getSigner();

const paymentIntent = JSON.parse(paymentData.paymentIntent);
const supportsEIP2612 = paymentData.metadata.supportsEIP2612;
let approvalSignature = undefined;
let approval = undefined;

if (supportsEIP2612) {
  approval = JSON.parse(paymentData.approvalPermitPayload);

  approvalSignature = await signer._signTypedData(
    approval.domain,
    approval.types,
    approval.values,
  );
} else {
  const tx = await signer.sendTransaction(paymentData.approvalCalldata);
  await tx.wait();
}

const paymentIntentSignature = await signer._signTypedData(
  paymentIntent.domain,
  paymentIntent.types,
  paymentIntent.values,
);

const signedData = {
  signedPaymentIntent: {
    signature: paymentIntentSignature,
    nonce: paymentIntent.values.nonce.toString(),
    deadline: paymentIntent.values.deadline.toString(),
  },
  signedApprovalPermit: approvalSignature
    ? {
        signature: approvalSignature,
        nonce: approval.values.nonce.toString(),
        deadline: approval?.values?.deadline
          ? approval.values.deadline.toString()
          : approval.values.expiry.toString(),
      }
    : undefined,
};

Send signed payment data with [POST /v2/request/payment-intents/{paymentIntentId}](https://api.request.network/open-api/#tag/v2request/POST/v2/request/payment-intents/{paymentIntentId}).

The API processes the payment and sends webhook lifecycle updates, including completion events.

Custom fee configuration

Custom fee configuration is available.

See Platform Fees for setup details (feePercentage, feeAddress) and implementation examples.