We returned to London for our second @encodeclub hackathon bringing together 150+ builders shipping on Arc. For the first time, teams experimented with nanopayments, unlocking new models for microtransactions, agentic commerce, and programmable stablecoin apps. Across six tracks, developers integrated Arc Testnet with Circle’s developer platform using USDC, USYC, StableFX, CCTP, Nanopayments, and Circle Wallets. → 80+ submissions → 8 winning teams The Arc team spent the weekend mentoring builders while @bleso_a walked through the new multichain Arc sample app to help teams get shipping faster. The Arc builder ecosystem keeps growing. Here’s what the winning teams built: 🏆 Nanopayments USDC-ME (1st): A gasless “Venmo for USDC” using Nanopayments where signed spend intents batch settle with near-zero fees. Blink (2nd): Streaming laptop insurance priced per-second using nanopayments. 🏆 Best Smart Contracts Chariot: A cross-chain lending protocol combining borrower interest with USYC T-bill returns. 🏆 Chain-Abstracted USDC Apps MeanTime: Turns CCTP transfer delays into tradable liquidity using Transfer-NFTs. 🏆 Global Payouts & Treasury Settl: A multi-chain payroll and treasury system that automates fund management, executes global USDC payouts, and includes built-in fraud detection and real-time treasury visibility. Zerra: A chain-abstracted storefront where merchants always receive USDC on Arc regardless of user assets. 🏆 Agentic Commerce OTTO: An AI treasury agent that manages USDC across chains, pays services with nanopayments, and allocates funds into USYC. 🏆 USYC / StableFX Integration Sphere: A visual treasury dashboard for managing wallets, swaps, USYC or DeFi routing, and automated financial workflows.