ArcPay ā Four ways to get paid. One URL.
ArcPay is a unified payments primitive on Arc Network. One URL ā arcpay.finance/@you ā accepts four payment modes for humans and AI agents: šø Tips. One-time USDC with a message. A Chrome extension injects a ā” Tip button into every tweet on X. Tips for handles without a registered wallet are held on-chain keyed by the handle ā claimable anytime via Twitter OAuth. š Subscriptions. Monthly or yearly USDC with per-second accrual and auto-prorated refunds on cancel. 2% protocol fee vs Patreon's 10%. Demo: arcpay.finance/demo-blog. š Content paywall. Gate articles, videos, courses. Pay once, on-chain receipt forever ā works even if the host disappears. Demo: arcpay.finance/demo-product. ā” Pay-per-call. x402-compatible / ERC-8183-ready billing for AI agents. batchPay(endpointId, N) prepays N inference credits in ONE transaction at 0.001 USDC/call. Each subsequent call is a wallet signature verified on-chain. Demo: arcpay.finance/demo-agent. Hackathon requirements met: ā¢ Per-action pricing: 0.001 USDC (10Ć under the $0.01 threshold) ā verified on-chain via PayPerCall.getEndpoint(). ā¢ 54 on-chain demo txs across 5 contracts, all 4 payment modes exercised (verified on testnet.arcscan.app). Evidence pack: github.com/wanggang22/arcpay/tree/main/demo-video/hackathon-evidence. ā¢ Margin: nanopayments break on L1 (gas $0.50ā$5 per call devours 99% of $0.001 revenue) and stretch on L2s (5ā95% burn). On Arc, gas is native USDC and sub-cent. Our PayPerCall contract shows 6 txs compressing to 60 logical calls via batchPay ā one transaction, ten prepaid credits, ten discrete signatures, settled in seconds. That economic model is impossible on any non-Arc chain today. Built solo in 3 days with Claude Code: 6 Solidity contracts (Foundry), TypeScript + Python SDKs (npm @wanggang22/arcpay-sdk + pip-from-git), Chrome extension v0.2.1 (MV3 zip at github.com/wanggang22/arcpay/releases), Next.js landing, Nextra docs, create-arcpay CLI scaffold. MIT at github.com/wanggang22/arcpay.
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"This is absurd output for a solo 3-day build. Seven deployed contracts, TypeScript and Python SDKs (npm published!), a CLI scaffolder with 5 templates, a Chrome extension on the Web Store, a polished landing page, dashboard, and docs site. The "4 modes, 1 URL" concept ā tips, subscriptions, content paywalls, and pay-per-call API credits ā is genuinely novel and well-unified. The TipJarByHandle feature (tip unregistered X users with on-chain escrow + OAuth PKCE claim) is the kind of creative thinking that wins hackathons. batchPay() prepaying N credits in one tx with off-chain signature verification per call is smart economics. 68 commits, clear unit economics, 2% protocol fee model. One of the strongest entries in the entire hackathon."
Vasu Raj Jain
Senior Software Engineer
For Innovators & Creators