--- url: /docs/stablecoin/quickstart.md description: >- Send your first stablecoin off-ramp payout on Base Sepolia, from minting test USDB to executing the payout. --- This quickstart walks through an off-ramp payout: pulling USDB from a blockchain wallet on Base Sepolia and delivering USD to a bank account. You will accept the terms of service, create a customer, add a bank account, create a payout quote, approve the token transfer, and execute the payout. ## Before you begin You need: * A BlindPay account and API key for a development instance * A wallet on Base Sepolia with ETH for gas and USDB to spend Get ETH from the [Base Sepolia faucet](https://www.alchemy.com/faucets/base-sepolia). Mint USDB (the development test token) at `https://app.blindpay.com/instances/YOUR_INSTANCE_ID/utilities/mint`. ## Steps ### Accept terms of service For testing you can accept the terms of service yourself. In production, your customer should be the one accepting them. ```bash [cURL] curl --request POST \ --url https://api.blindpay.com/v1/e/instances/in_000000000000/tos \ --header 'Authorization: Bearer YOUR_API_KEY' \ --header 'Content-Type: application/json' \ --data '{ "idempotency_key": "" }' ``` Open the returned URL in your browser, accept the terms, and copy the `tos_id` shown on the confirmation screen. You will need it to create the customer. ### Create a customer Every payout requires a customer that has completed KYC. On development instances, customers are auto-approved. ```bash [cURL] curl --request POST \ --url https://api.blindpay.com/v1/instances/in_000000000000/customers \ --header 'Authorization: Bearer YOUR_API_KEY' \ --header 'Content-Type: application/json' \ --data '{ "tos_id": "to_000000000000", "type": "individual", "kyc_type": "standard", "email": "email@example.com", "tax_id": "12345678", "address_line_1": "8 The Green", "address_line_2": "#12345", "city": "Dover", "state_province_region": "DE", "country": "US", "postal_code": "02050", "ip_address": "127.0.0.1", "phone_number": "+1234567890", "proof_of_address_doc_type": "UTILITY_BILL", "proof_of_address_doc_file": "https://pub-4fabf5dd55154f19a0384b16f2b816d9.r2.dev/v4-460px-Get-Proof-of-Address-Step-3-Version-2.jpg.jpeg", "first_name": "John", "last_name": "Doe", "date_of_birth": "1998-01-01T00:00:00Z", "id_doc_country": "US", "id_doc_type": "PASSPORT", "id_doc_front_file": "https://pub-4fabf5dd55154f19a0384b16f2b816d9.r2.dev/1000_F_365165797_VwQbNaD4yjWwQ6y1ENKh1xS0TXauOQvj.jpg", "selfie_file": "https://pub-4fabf5dd55154f19a0384b16f2b816d9.r2.dev/selfie.png" }' ``` This is the full standard KYC payload (`kyc_type: "standard"`): identity document, selfie, and proof of address. Save the customer ID (`re_...`) from the response. ### Add a bank account This is the fiat destination for the payout, the bank account that receives the USD once the stablecoin is converted. This example adds a US ACH account. Use real, valid bank details, even on development. ```bash [cURL] curl --request POST \ --url https://api.blindpay.com/v1/instances/in_000000000000/customers/re_000000000000/bank-accounts \ --header 'Authorization: Bearer YOUR_API_KEY' \ --header 'Content-Type: application/json' \ --data '{ "type": "ach", "name": "Display Name", "beneficiary_name": "", "routing_number": "", "account_number": "", "account_type": "checking", "account_class": "individual" }' ``` Save the bank account ID (`ba_...`). ### Create a payout quote A quote locks the conversion rate and fees for 5 minutes. On development instances the token is always `USDB`, BlindPay's test stablecoin, minted on `base_sepolia` in this example. ```bash [cURL] curl --request POST \ --url https://api.blindpay.com/v1/instances/in_000000000000/quotes \ --header 'Authorization: Bearer YOUR_API_KEY' \ --header 'Content-Type: application/json' \ --data '{ "bank_account_id": "ba_000000000000", "currency_type": "sender", "cover_fees": false, "request_amount": 5000, "network": "base_sepolia", "token": "USDB" }' ``` `request_amount` is an integer in minor units, `5000` is $50.00. `cover_fees: false` means the customer's stablecoin amount absorbs the fee, the common case. The response includes a `contract` object with the ERC-20 token address, ABI, BlindPay's contract address, and the amount to approve, everything the next step needs. ### Authorize and execute Every stablecoin on BlindPay is an ERC-20 token, so on EVM chains you authorize the transfer by calling `approve` on the token contract before creating the payout. This example uses [express.js](https://expressjs.com/en/starter/hello-world.html) and [ethers.js](https://docs.ethers.org/v6/) to run all three steps (quote, approve, execute) in one request handler. Make sure [Node.js](https://nodejs.org/en/download/) is installed, then create a project and install the dependencies: ```bash npm init npm install express ethers ``` Create `index.js`: ```js [index.js] import express from 'express' import { ethers } from 'ethers' const app = express() app.get('/', async (req, res) => { // Before start const rpcProviderUrl = '' // Get one from https://chainlist.org/?search=base&testnets=true const walletPrivateKey = '' // Must hold ETH and USDB on Base Sepolia const instanceId = '' const blindpayApiKey = '' const bankAccountId = '' // BlindPay API config const headers = { 'Content-Type': 'application/json', 'Authorization': `Bearer ${blindpayApiKey}`, } // 1. Create a quote const fiftyDollars = 5000 const quoteBody = { bank_account_id: bankAccountId, currency_type: 'sender', cover_fees: false, request_amount: fiftyDollars, network: 'base_sepolia', // also: "sepolia", "arbitrum_sepolia", "polygon_amoy" token: 'USDB', // always "USDB" on development instances } const createQuote = await fetch(`https://api.blindpay.com/v1/instances/${instanceId}/quotes`, { headers, method: 'POST', body: JSON.stringify(quoteBody), }) const quoteResponse = await createQuote.json() // 2. Approve tokens const provider = new ethers.JsonRpcProvider(rpcProviderUrl, quoteResponse.contract.network) const yourWallet = new ethers.Wallet(walletPrivateKey, provider) const contract = new ethers.Contract(quoteResponse.contract.address, quoteResponse.contract.abi, provider) const contractSigner = contract.connect(yourWallet) await contractSigner.approve( quoteResponse.contract.blindpayContractAddress, quoteResponse.contract.amount, ) // 3. Execute the payout const senderWalletAddress = await yourWallet.getAddress() const payoutBody = { quote_id: quoteResponse.id, sender_wallet_address: senderWalletAddress, } const executePayout = await fetch(`https://api.blindpay.com/v1/instances/${instanceId}/payouts/evm`, { headers, method: 'POST', body: JSON.stringify(payoutBody), }) const payoutResponse = await executePayout.json() res.send(payoutResponse) }) /* istanbul ignore next */ app.listen(3000) console.log('Express started on port 3000') ``` Run it and open `http://localhost:3000`: ```bash node index.js ``` On a development instance, the payout completes automatically a few seconds after creation, no manual settlement step needed. You will receive a `payout.complete` webhook once it does. ## Next steps This quickstart covered the EVM path on Base Sepolia. BlindPay also supports Stellar (authorize + signed XDR) and Solana (token delegation) for off-ramp payouts. ## Related * [Off-ramp](/stablecoin/send): full reference, including Stellar and Solana authorization * [On-ramp](/stablecoin/receive): accept fiat and deliver stablecoins to a wallet * [Managed wallet](/stablecoin/store): hold stablecoins per customer without external wallet signing * [Webhooks](/learn/webhooks): handle `payout.complete` and other real-time events * [KYC](/kb/kyc): customer verification levels and required fields