Agent payments verify the agent. Who verifies the human?
2025–26 settled how agents pay: x402 proved stablecoin micropayments at machine speed, Google AP2 made consent cryptographically auditable with mandate credentials, Mastercard Agent Pay bound cards to registered agents with Agentic Tokens, and Visa's Trusted Agent Protocol attested agent identity in signed headers. Each one is real engineering — and each one verifies the agent and the mandate.
Three claims are still open on every rail, and they're all about humans: (1) the principal — is a real, unique human behind this agent's authority? (2) the delegation — did that human grant this specific, scoped, revocable authority? (3) the fulfillment — when an agent pays for human work, did a real human deliver it? 5arz issues exactly those three, as signed ES256 credentials anyone verifies against a public JWKS — rail-neutral by design.
How the claims map to each protocol
| Rail | What it verifies today | What 5arz adds |
|---|---|---|
| x402 (Coinbase) | Payment settles machine-to-machine in USDC | Live 402-native checkout for verified human work + on-chain isVerifiedHuman(wallet) on the same chain (Base) |
| Google AP2 | Intent/Cart Mandates as W3C VCs | PoHF as a companion credential inside the mandate: the signing principal is a verified unique human; fulfillment receipts close the loop |
| Mastercard Agent Pay | Agentic Token binds card ↔ agent ↔ consent policy | Human-binding behind the token + scoped human→agent Delegation Proof + Proof-of-Fulfillment for Agent Pay for Machines |
| Visa TAP | Signed headers attest agent identity + intent | RFC 9421-native: a 5arz human-principal claim rides alongside TAP headers; issuer-grade revocation via status API + on-chain read |
What a 5arz credential is
A compact ES256 JWT with claims like human, unique_human, liveness, wallet (EIP-191-proven), task_type, and a cross-commitment hash — minted only after government-ID verification (Stripe Identity), liveness, and device attestation. Verify it offline with any JWT library against api.5arz.com/.well-known/jwks.json; read it on-chain on Base. No raw biometrics, ever. Price a task with the VHH Index — the published USD reference rate for a verified human hour.
Integrate in an afternoon
Agent-native: MCP at mcp.5arz.com (verify/integrate) and api.5arz.com/mcp (commerce) · OpenAPI: /openapi.json (26 paths) · npm @5arz/verify / pip sarz-verify with LangChain/CrewAI/Vercel-AI tool definitions · free unlimited sandbox: POST /api/agents/register {"mode":"test"}. Platform reality: 101 verified humans · 18 countries · 5,740 verified completions. Protocol briefs for each rail: /agentic-commerce.
x402 checkout is in developer preview on Base Sepolia; mainnet settlement rolling out. Patents pending US 63/979,052 · US 63/979,474.