wang ligang@Gavin

ArcPay is a unified payments primitive on Arc Network. One URL — arcpay.finance/@you — accepts four payment modes for humans and AI agents: 💸 Tips. One-time USDC with a message. A Chrome extension injects a ⚡ Tip button into every tweet on X. Tips for handles without a registered wallet are held on-chain keyed by the handle — claimable anytime via Twitter OAuth. 📅 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. 🔒 Content paywall. Gate articles, videos, courses. Pay once, on-chain receipt forever — works even if the host disappears. Demo: arcpay.finance/demo-product. ⚡ 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: • Per-action pricing: 0.001 USDC (10× under the $0.01 threshold) — verified on-chain via PayPerCall.getEndpoint(). • 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. • Margin: nanopayments break on L1 (gas $0.50–$5 per call devours 99% of $0.001 revenue) and stretch on L2s (5–95% burn). On Arc, gas is native USDC and sub-cent. Our PayPerCall contract shows 6 txs compressing to 60 logical calls via batchPay — 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.

Grab your ideas, spin up compute, and start building what’s next! Start with $100 in AMD Developer Cloud credits and begin building right away. Get access to hands-on tutorials, workshops, and curated learning resources to help you build faster and go further. To unlock credits and join the hackathon, sign up for the AMD AI Developer Program. 🤝 Go solo or team up — ship something real. 💰 $21,500+ total prize pool & 1 × AMD Radeon™ AI PRO R9700 GPU up for grabs. 📍 On-site Venue (May 9-10): MindsDB SF AI Collective 3154 17th St, San Francisco, California, USA 📍On-site participation is by invitation only. Travel and accommodation expenses will not be covered. 🧑‍💻 Developers, builders, and innovators - bring your boldest ideas and let’s turn them into real AI systems on AMD.

In this hybrid hackathon powered by Arc and Circle, developers will build the next generation of Agentic economic applications using Circle’s Nanopayments infrastructure with settlement on Arc in USDC. For the first time, high-frequency, usage-based transactions between users, APIs, and AI agents can operate without gas overhead eroding margin. Arc provides stablecoin-native settlement with predictable, dollar-denominated USDC fees and deterministic, sub-second finality — enabling real-time coordination and economically viable per-action pricing at scale. 📅 April 20 – 26, 2026 • Apr 20 – 25 (Online): Submit projects by Apr 25. • Apr 25 (On-site Build – SF, CA): Teams refine projects. • Apr 26 (On-site Demos & Awards – SF, CA): Live pitches & winners announced. Get guidance from Arc and Circle experts through on-site support. 📍 On-site Venue (April 25-26): MindsDB SF AI Collective 3154 17th St, San Francisco, California, USA 🤝 Go solo or team up, it's your flow. 🏆 Compete for a $15,000+ Prize Pool. 📍 Please note: If approved for the on-site experience, you’ll also have the opportunity to showcase your project live. Travel and accommodation will not be covered. 🧑🏻‍💻 Secure your spot now – sign up before the Kick-Off Stream!