wdk-protocol-fiat-peer

Peer Cash for Tether WDK. The module implements WDK's IFiatProtocol for cashing out Base USDC to supported fiat payment platforms at the live oracle rate.

Peer Cash is off-ramp only. quoteBuy() and buy() reject with a typed unsupported_operation error.

Install

npm install wdk-protocol-fiat-peer

Quote a cash-out

import PeerFiatProtocol from 'wdk-protocol-fiat-peer';

const fiat = new PeerFiatProtocol(account);

const quote = await fiat.quoteSell({
  cryptoAsset: 'usdc',
  fiatCurrency: 'EUR',
  cryptoAmount: 25_000_000n,
  config: { platform: 'revolut', includeEta: true },
});

quote.cryptoAmount;
quote.fiatAmount;
quote.rate;
quote.metadata;

Amounts follow the WDK contract: cryptoAmount is in Base USDC base units and fiatAmount is in the fiat currency's minor unit. A quote is an oracle estimate, not a locked rate. The binding rate is the live oracle rate when a buyer fills the order.

Prepare a cash-out

Supply a payout platform and payee to have sell() return unsigned transactions:

const result = await fiat.sell({
  cryptoAsset: 'usdc',
  fiatCurrency: 'EUR',
  cryptoAmount: 25_000_000n,
  config: {
    platform: 'revolut',
    payee: '@alice',
  },
});

for (const [index, transaction] of result.prepared?.txs.entries() ?? []) {
  console.log(result.prepared?.steps[index], transaction);
}

The WDK host must inspect, sign, and submit prepared.txs in order. The module never accepts a private key or broadcasts a transaction. If prepared.accessPolicyRequired is true, finalize the confirmed create-deposit receipt with @zkp2p/cash, then prepare and submit its access-policy transaction.

Some payout platforms require a pre-existing verified payee. For those platforms, a new bare handle returns the SDK's PAYEE_VERIFICATION_REQUIRED error; pass prepared curator payee data or complete verification in the Peer app.

If config.platform and config.payee are both omitted, sell() returns https://app.peer.xyz/cash as the standard WDK sellUrl and does not register a payee or prepare transactions.

Resume an order

Use the composite Peer deposit ID as WDK's transaction ID:

const transaction = await fiat.getTransactionDetail(depositId);

transaction.status;
transaction.metadata.order;

Peer states map to WDK as follows:

• delivered → completed
• returned → failed
• all active states → in_progress

Supported surface

• Asset: USDC on Base, 6 decimals
• Fiat currencies and payout platforms: read live from @zkp2p/cash
• Pricing: 0% protocol spread, live oracle rate at fill time
• Countries: Peer exposes availability by payout platform and currency rather than by country, so getSupportedCountries() returns an empty list instead of inventing a country gate
• Runtime: browser and Node.js 20.19+

Configuration

const fiat = new PeerFiatProtocol(account, {
  environment: 'production',
  referralCode: 'ABC123',
  appUrl: 'https://app.peer.xyz/cash',
});

refundAddress is rejected. Peer Cash returns any withdrawal to the depositing wallet, so the module never silently promises a different refund destination.

Development

npm install
npm run validate