anh pham ngoc@anhpt96346

THE PROBLEM The internet has no pay-per-request layer. Today an AI agent wanting to compare 50 flight APIs has three bad options: sign up for 50 credit cards, scrape illegally, or pay onchain and watch $0.001 calls cost $2 in gas. Pay-per-query search, micro-SaaS, per-paragraph news, agent marketplaces — all economically impossible on existing rails. THE SOLUTION AgentCart is a mobile wallet + AI agent that treats every API as a vending machine. User types a request in Vietnamese or English: "Vé bay Hà Nội → Tokyo tháng 6". The agent expands this into 48 parallel API calls across 15 merchants, pays each $0.0012–$0.0025 via x402 + EIP-3009, and returns the best deal. Natural-language budget rules (parsed by Gemini or regex fallback) gate every single signature before it's created. WHY THIS IS ONLY POSSIBLE ON ARC A single $0.0012 API call on Ethereum L1 costs ~$2 in gas — 166,666% overhead. On Arbitrum/Base with $0.05 gas it is still 4,166% overhead. Only Arc + Circle Nanopayments makes the math work: USDC-denominated gas paid once at deposit, 48+ signatures batched into one onchain settlement, deterministic sub-second confirmation per payment. WHAT WE BUILT Next.js PWA with embedded viem wallet. Full x402 v1 handshake (GET → 402 → EIP-3009 sign → retry with X-PAYMENT header). Real EIP-712 signature recovery on every merchant route. 15 in-repo merchant endpoints at realistic sub-cent pricing. Append-only ledger with 57+ tx audit trail live on production. CLI seed script for judges to verify transactions independently. PRODUCTION METRICS Live: https://agentcart-two.vercel.app Ledger: https://ag

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!