ArcShopper

arc-shopper is an experimental autonomous commerce agent that demonstrates machine-to-machine purchasing using the x402 HTTP Payment Protocol. It showcases a fully integrated end-to-end flow where an AI-driven agent autonomously discovers products, evaluates them, and completes purchases without manual checkout interaction, enabled by cryptographically-signed payment authorizations embedded directly within HTTP request/response cycles. At its core, arc-shopper implements a protocol extension to HTTP that eliminates traditional user checkout interactions. When a server returns a 402 Payment Required response, the client automatically constructs a signed payment payload according to the x402 specification, performs payment settlement on a blockchain testnet, and then retries the request to receive the gated content. This flow is supported from wallet provisioning through on-chain settlement and content delivery, demonstrating autonomous digital commerce. The system’s architecture consists of three main layers. The Client Layer authenticates users and provisions wallets, either via a primary custodial wallet service or a fallback deterministic wallet. The Agent Layer includes an LLM-powered shopping agent that interprets user queries, performs product searches, extracts purchasing intent, and applies a policy engine to enforce spending limits, daily caps, and category restrictions. The Payment Layer constructs EIP-712 signed x402 payloads and interacts with a local facilitator service to verify and settle transactions on the Arc testnet. Once payment is confirmed, the originally requested content is served. The repository also includes a digital product catalog API, wallet and payment facilitation endpoints, and a complete backend running on Node.js with TypeScript. It serves as a proof-of-concept for autonomous commerce agents that leverage cryptographic payment flows and blockchain settlement to perform digital purchases without human checkout steps.