ArcPort

ArcPort is an API payment layer for agents on Arc. ArcPort V2 introduces session-based API payments for repeated agent usage. The core idea is simple: agents should not treat every repeated API or model call as a separate payment event. The demo shows one complete lifecycle. An operator starts with a funded Circle wallet, opens a 0.01 USDC session onchain, then an agent makes repeated paid Gemini Inference calls through signed offchain vouchers. After the calls, the session is closed once onchain. ArcPort settles cumulative spend, refunds the unused balance, and shows the full proof: open tx, close tx, calls total, cumulative spent, refund, and channel status. ArcPort has two payment modes. Charge mode is the simple path for one-off calls through Circle Nanopayments. Session mode is the differentiator: one onchain open, many signed offchain calls, one onchain close, and refund of unused budget. This matters because $0.001 API pricing breaks if every request needs its own onchain payment transaction. ArcPort focuses on the reusable payment primitive behind repeated agent API and model usage, rather than a single vertical app or a transaction-count demo. The web app is the operator control plane for wallet setup, session management, and proof. The runtime user is the agent integrating through the API layer.