StreamPay — Real-time USDC Streaming on Arc

Released April 30, 2026 • Tags: Arc Network DeFi Streaming Payments Smart Contracts

StreamPay is a real-time USDC payment streaming protocol built natively on Arc. Instead of sending lump-sum payments, USDC flows continuously to recipients second by second. Features instant withdrawals, fair refunds on cancellation, and sub-second deterministic finality powered by Arc's infrastructure.

What is StreamPay?

StreamPay revolutionizes how payments are made by enabling continuous money streams. Instead of sending a one-time payment, a sender deposits USDC into a stream — and it flows continuously to the recipient, second by second, until the stream ends or is cancelled.

Why Arc?

Sub-second deterministic finality — Payments settle the moment you click, no waiting for confirmations
$0.01/tx gas in USDC — Makes per-second micropayment streams economically viable, impossible on chains with volatile gas
ERC-20 USDC as native token — No currency conversion, no volatility exposure

Live Contracts (Arc Testnet)

StreamPay Contract

0x46937C3663101b3fE7F282A49F397d1f5C17a54B

View on ArcScan →

USDC Contract

0x3600000000000000000000000000000000000000

View on ArcScan →

Network Details

Network: Arc Testnet
Chain ID: 5042002
RPC: https://rpc.testnet.arc.network

How It Works

StreamPay operates through four onchain actions that enable continuous payment flows:

1. Create Stream

Sender approves USDC and creates a stream with a specified rate per second

2. Continuous Flow

USDC flows automatically from sender to recipient every second

3. Withdraw Anytime

Recipient can withdraw earned USDC at any time with no gas cost (view function)

4. Cancel for Refund

Sender can cancel stream anytime — earned USDC goes to recipient, unspent returns to sender

Technical Design

USDC Decimal Safety

StreamPay handles USDC's 6 decimal precision correctly, ensuring accurate rate calculations and preventing precision loss in streaming payments.

Rate Precision

The protocol uses high-precision rate calculations to ensure that per-second flows are accurate and predictable, even for very small payment amounts.

Withdrawable Calculation (View, No Gas)

Recipients can check their withdrawable balance at any time through a view function that requires no gas, enabling real-time balance tracking without transaction costs.

Use Cases

Freelancer Payments

Get paid continuously while working
Withdraw earnings as you go
No waiting for payment cycles

Salary Streaming

Continuous salary payments throughout the month
Instant access to earned wages
Transparent payment tracking

Service Subscriptions

Pay for services by the second
Stop payments instantly when service ends
Fair refunds for unused time

DAO Bounties

Stream payments for ongoing contributions
Adjust rates based on performance
Transparent treasury management

Quickstart

1. Add Arc Testnet to MetaMask

Network Name: Arc Testnet

RPC URL: https://rpc.testnet.arc.network

Chain ID: 5042002

Currency Symbol: USDC

2. Install & Build

npm install
npm run build

3. Deploy Contracts

npx hardhat run scripts/deploy.js --network arcTestnet

4. Configure & Run Web UI

cd web
npm install
npm run dev

Web UI Features

Create and manage payment streams
Real-time balance tracking
Instant withdrawal interface
Stream cancellation with refund preview
CSV export for payment history

Built on Arc

StreamPay leverages Arc Network's unique capabilities to enable real-time payment streaming that's economically viable and user-friendly. Arc's stablecoin-native infrastructure and sub-second finality make it the perfect foundation for continuous payment protocols.

🌐 Visit Streampay

📚 Source Code

Check out the complete source code on GitHub:

https://github.com/dhozil/streampay

Built by dhozil for Arc Network Testnet 🚀