ArcReflex

Most agent payment demos show money moving. ArcReflex shows money being withheld, and that distinction is the whole point. The system runs five concurrent FastAPI microservices: two search agents, two filter agents, and a fact-check agent. An orchestrator picks between them based on live reputation scores and per-query pricing. When an agent returns acceptable results, the orchestrator releases a sub-cent USDC nanopayment via Circle's infrastructure. When results fall below the quality threshold, the payment is blocked, the agent's reputation takes a hit, and the task gets rerouted to the backup. The fact-check agent sits behind x402 middleware, so it will not accept any request that does not arrive with a valid payment receipt. No receipt, no access, full stop. To prove this is deterministic and not just a happy path demo, ArcReflex ships a judge mode. One command triggers a forced red-team scenario: Search Agent A degrades, the orchestrator catches it, withholds the payment, fails over to Agent B, and writes a SHA-256 signed evidence bundle to disk. An independent verifier script checks the bundle without importing any orchestrator code. The hashes either match or they do not. AgentRegistry.vy is the on-chain ledger that tracks agent addresses, reputation, and status on Arc. All settlement uses USDC. The frontend connects via WebSocket and shows payment events, quality gate decisions, and agent switching in real time, with a dedicated judge tab for exporting the evidence. The margin math is simple: at $0.0002 per query across 50+ transactions, traditional gas fees would cost more than the payments themselves. Nanopayments on Arc make the model viable. Gas fees on any other chain would kill it.