A debit card your users fund with stablecoins. Issued in seconds.

Your users sign in with email or social and get an embedded wallet and a virtual Visa card in the same flow. They fund it gaslessly from their own stablecoin balance and spend it anywhere Visa is accepted - issue, fund, and reveal the card in a handful of calls.

Built withRain issuing API

@dynamic-labs-sdk/client@dynamic-labs-sdk/react-hooks@dynamic-labs-sdk/evm

Create the wallet

Docs

One Dynamic client per app. The EVM extension gives every user an embedded wallet - the card's funding source and the signer for gasless transfers.

lib/dynamic-client.ts

import { createDynamicClient } from "@dynamic-labs-sdk/client";
import { addEvmExtension } from "@dynamic-labs-sdk/evm";

export const client = createDynamicClient({
  environmentId: process.env.NEXT_PUBLIC_DYNAMIC_ENVIRONMENT_ID!,
});
addEvmExtension(client);

Issue the card

On your server - the Rain Api-Key never touches the browser. Submit the KYC application for a userId, then issue a virtual card for that user.

server/issue-card.ts

const RAIN = "https://api-dev.raincards.xyz/v1/issuing";
const auth = {
  "Api-Key": process.env.RAIN_API_KEY!,
  "Content-Type": "application/json",
};

// POST /v1/issuing/applications/user  ->  KYC, returns the Rain userId
const { userId } = await fetch(`${RAIN}/applications/user`, {
  method: "POST",
  headers: auth,
  body: JSON.stringify(application),
}).then((r) => r.json());

// POST /v1/issuing/users/:userId/cards  ->  the virtual card
const card = await fetch(`${RAIN}/users/${userId}/cards`, {
  method: "POST",
  headers: auth,
  body: JSON.stringify({ type: "virtual" }),
}).then((r) => r.json());

Reveal card details

The plaintext PAN/CVC never touch your server. The browser mints an AES key and passes its SessionId; Rain returns the secrets ENCRYPTED, your server relays them, and the browser decrypts locally.

server/card-secrets.ts

// GET /v1/issuing/cards/:cardId/secrets   (SessionId = the browser's key)
const encrypted = await fetch(`${RAIN}/cards/${cardId}/secrets`, {
  headers: { "Api-Key": process.env.RAIN_API_KEY!, SessionId: sessionId },
}).then((r) => r.json());

// Relay `encrypted` to the browser, which decrypts with its own key.
const pan = await decryptSecret(encrypted.encryptedPan, secretKey);
const cvc = await decryptSecret(encrypted.encryptedCvc, secretKey);

Read the balance

Spending power comes straight from Rain, keyed by the userId. Read it on your server and surface it to the UI.

server/balance.ts

// GET /v1/issuing/users/:userId/balances
const balance = await fetch(`${RAIN}/users/${userId}/balances`, {
  headers: { "Api-Key": process.env.RAIN_API_KEY! },
}).then((r) => r.json());

balance.spendingPower; // what the card can spend right now

Get the deposit address

Each user has a per-chain Rain deposit contract; stablecoins sent to it fund the card. Fetch it (or create it once) for the funding chain.

server/deposit-address.ts

// GET /v1/issuing/users/:userId/contracts
// (POST the same path with { chainId } to create one the first time)
const contracts = await fetch(`${RAIN}/users/${userId}/contracts`, {
  headers: { "Api-Key": process.env.RAIN_API_KEY! },
}).then((r) => r.json());

const depositAddress = contracts.find(
  (c) => c.chainId === 84532, // Base Sepolia
)?.depositAddress;

Fund it gaslessly

Docs

Back in the browser: a sponsored stablecoin transfer from the user's embedded wallet to that Rain deposit address - EIP-7702, no native gas, no approval popups.

hooks/use-fund-card.ts

import { sendSponsoredTransaction } from "@dynamic-labs-sdk/evm";

const { transactionHash } = await sendSponsoredTransaction({
  walletAccount,
  calls: [
    {
      target: USDC_ADDRESS,
      data: encodeTransfer(depositAddress, amount),
    },
  ],
});