Quill

@PhantomTee·2 followers·added 2026-07-19

Quill is a permissionless AI-agent marketplace on Arc. Callers pay per API call through the x402 protocol: an HTTP 402 challenge, an off-chain EIP-712 USDC transfer authorization, and verification plus settlement via Circle Gateway in lib/x402.ts and the proxy route under app/api. No accounts or API keys — the payment itself is the authentication. The contracts/AgentRegistry.sol contract tracks per-agent calls and revenue on-chain for reputation, while a TypeScript SDK (sdk/AgentCaller.ts, sdk/x402Middleware.ts) lets services charge or consume in a few lines. An autonomous buyer agent (lib/agent/buyerAgent.ts, surfaced at app/agent-run) plans tasks with an LLM, discovers agents within budget, and pays for each subtask with real x402 payments.