Verifiable commerce for AI agents, on Arc

AgentTrust is a commerce control plane an API provider puts in front of its endpoints so AI agents can be accepted as paying customers. Every agent request runs a deterministic flow: agent → HTTP 402 → USDC payment → upstream call → signed receipt → hash-chain → Arc anchor. We coordinate the flow and never hold funds: zero custody, no token, no new chain.

Why Arc

Arc is USDC-native at the gas layer, targets sub-second deterministic finality, and is designed around agentic commerce, which is exactly the shape of our traffic: many small, metered, machine-to-machine payments that must settle and prove instantly. The head of each provider’s receipt chain anchors to the Arc testnet AnchorRegistry, so the record is settlement-grade rather than a claim on our own database.

Circle products in our architecture

• Arc testnet (chainId 5042002). Three contracts deployed and verified — ReceiptVerifier 0x489670…, AgentRegistry 0xC4e5A1…, AnchorRegistry 0x7cDa40…. The first receipt-chain head anchor is live: 0x8e31a3fb1e82…, product-verifiable at /verify/anchor. Arc is testnet only — no mainnet or live Arc claim.
• x402, with the Circle Gateway facilitator profile. The 402 payment lane speaks x402 and includes a Circle Gateway wire profile (GatewayWalletBatched) that is implemented and regression-tested. To be exact: the live sandbox currently runs the facilitator.x402.rs facilitator in sandbox mode; the Circle Gateway path is code-complete and gated, not yet the live sandbox default.
• USDC settlement. A real end-to-end USDC settlement is on record: a Base mainnet x402 canary, 0.01 USDC, verified on-chain.

See it yourself

Public surfaces, no credentials needed:

• /playground — run the 402 → pay → 200 + receipt flow in your browser.
• /verify — paste any receipt; it verifies offline against the published Ed25519 key.
• /v1/providers/demo/receipt-chain — the demo provider’s signed, hash-chained receipts, walkable by slug.
• /proof-center — the Base canary and the Arc anchor side by side.

Honest status

Posture is private design-partner alpha, preparing for Arc mainnet. What is not claimed:

• No SOC 2, ISO 27001, HIPAA, or PCI — none held, none claimed.
• No mainnet or live Arc claim — Arc work is testnet only.
• No revenue and no signed customer — external operator verification is not ready yet.
• No production stablecoin movement until a merchant passes sandbox round-trips and explicitly opts in.
• Inline-path billing is at-least-once under client retry, not exactly-once: a retried call that re-executes is charged again. Durable exactly-once settlement lands with M1.5.

Milestones

Sequenced, not dated. Each carries a measurable acceptance criterion.

1. M1 — revenue capability (shipped, live). The platform-billing credit gate runs in the deployed request path, and the ledger’s reserve / commit / release mechanics are test-proven. This is revenue capability, not revenue collected: the on-chain top-up claim route ships dormant (returns disabled) until wallet-binding, and there is no external provider yet, so nothing is billed today. Live now: the top-up route is verifiably dormant and the credit schema is live on /ready. Test-proven, not yet live traffic: an exhausted balance returns 503 and a settled call deducts one credit per receipt. First actual collection is M2.
2. M1.5 — durable settlement. Enable the atomic commerce state machine in a controlled deploy, add the durable Postgres x402 replay guard, and resolve the mandate issuer trust-anchor. Acceptance: the commerce path is live with exactly-once settlement and a durable, cross-pod replay guard.
3. M2 — first external design partner. One API provider, not the operator, runs live agent traffic through the gateway. Acceptance: receipts on their live traffic, independently verifiable at /verify, and external operator verification flips from not-ready to ready.
4. M3 — Arc mainnet + agent reputation. Migrate the settlement + anchor lane to Arc mainnet and add an ERC-8004-compatible reputation read layer for agents. Acceptance: a receipt-chain head anchored on Arc mainnet and a public agent-reputation read resolving against on-chain registry data.