arc-payment-starter

Build your first stablecoin payment flow on Arc Testnet in under an hour.

Three scripts, no UI, no framework. You provision a wallet, watch a USDC payment arrive, and (optionally) withdraw the funds. Gas is sponsored by Circle Gas Station — you never hold native tokens.

What you build

By the end you will have:

• A receive address on Arc Testnet, provisioned via Circle
• A live terminal session watching for incoming USDC
• Optionally, a withdrawal flow that sends the received USDC to your own EOA

Everything runs from the CLI. No Solidity. No frontend.

Prerequisites

• Node.js v22 or later
• A free Circle Developer account: https://console.circle.com
• Some testnet USDC on Arc Testnet (faucet: https://faucet.circle.com)
• An EOA wallet (MetaMask, Rabby, anything) for the withdraw step

Setup

git clone https://github.com/Adeyemir/arc-payment-starter-.git
cd arc-payment-starter-
npm install
cp .env.example .env

Open .env and fill in two values from Circle Console:

• CIRCLE_API_KEY — Standard Key, generated under Keys
• CIRCLE_ENTITY_SECRET — generated under Configurator, then registered

(See the workshop notes for the exact Console steps. The whole flow takes ~5 min.)

Run the flow

Step 1 — Provision a receive address

npm run wallet

Prints a WALLET_ID and WALLET_ADDRESS. Copy both into .env.

The address is an SCA on Arc Testnet. Gas Station covers everything it does.

Step 2 — Watch for an incoming payment

npm run watch

The script polls the USDC contract on Arc Testnet every 5 seconds. Open a second terminal or your wallet, send USDC to WALLET_ADDRESS, and watch the confirmation print live.

Example output:

=== WATCHING FOR USDC PAYMENTS ===

Wallet  : 0xAbCd...
Chain   : Arc Testnet
Polling : every 5 seconds

Starting balance: 0.00 USDC

Send USDC to the wallet above. Watching for changes...

[14:32:18] Payment received: 5.00 USDC
[14:32:18] New balance     : 5.00 USDC

Step 3 (optional) — Withdraw to your own wallet

Add a MERCHANT_ADDRESS to .env (your MetaMask address works) and run:

npm run withdraw

Submits a transfer via Circle's createTransaction. Sends the wallet's USDC balance (minus a tiny buffer) to MERCHANT_ADDRESS. Gas Station sponsors the transfer — no native tokens needed.

Check the result on Arc Scan: https://testnet.arcscan.app/address/<your-merchant-address>

What you just learned

• Circle DCW provisions SCA wallets on any supported chain in one API call
• Circle Gas Station sponsors gas on testnet automatically
• Arc Testnet finality is sub-second — payments confirm fast
• Polling a balance is enough for a receive-only payment listener (no indexer needed)

Where to go next

• Fork this and add a Next.js checkout page (the same flow, with a UI)
• Add multi-chain receive using DCW on ['BASE-SEPOLIA', 'ARC-TESTNET']
• Route cross-chain settlements through Circle Gateway (advanced)
• See github.com/Adeyemir/arc-contracts to deploy your own ERC-1155 token using the same Circle stack

Resources

• Arc Network: https://www.arc.io
• Arc Docs: https://docs.arc.io
• Circle Developer Docs: https://developers.circle.com
• Arc Scan (testnet): https://testnet.arcscan.app

License

MIT