Proof and Circle Internet Group today announced collaboration showing how verified legal identity and machine-native payments can work together in agent transactions. At Money20/20, teams will demonstrate AI agent completing identity-gated purchase where agent presents verified Proof credential using x401 and pays merchant in USDC over x402 from Circle Agent Wallet.
AI agents can already find services, place orders and pay. Business on other side still can't reliably tell who sent agent or whether that person approved transaction. Without that, only safe choices are to block agents or let them through blind.
Second gap: Identity providers that have already verified person have no practical way to be paid when verification reused somewhere new. Business that wants to rely on another company's identity check usually needs contract with provider first, which limits verified identity to few businesses that signed up in advance.
Two open protocols now address both halves. x402, which Circle supports across its agentic products, uses web's HTTP 402 Payment Required response so site can tell agent what payment it needs. x401, which Proof published in June, uses HTTP 401 Unauthorized response so site can tell agent what proof of identity it needs. One answers how agent pays, other answers who it acts for. Used together, they also let business pay identity provider for each check on spot, without sales process.
Identity request alongside price: Merchant responds to agent with two requirements. First is x401 request naming fact it needs, credential issuers it trusts and how strongly identity must have been verified. Second is x402 payment request in USDC.
Verified credential disclosed selectively: Proof wallet presents person's verified credential along with signed approval for specific purchase. Proves only relevant facts without revealing rest of ID. Merchant checks credential's signature against Proof's published public keys, without calling Proof or storing personal information. Payment in USDC: Agent pays merchant in USDC over x402 from Circle Agent Wallet, and order completes. Merchant keeps signed, tamper-evident evidence of who approved purchase, which it can use if transaction later disputed.
Proof and Circle share interest in how agent identity and agentic payments fit together, including how businesses could pay identity issuers for each verification in USDC over x402. Proof prices identity claims individually to confirm single fact such as age. If those payments settle over x402, protocol could run in both directions in one transaction: shopper's agent pays merchant, and merchant pays identity issuer.
Proof and Circle will show flow end to end at Money20/20 in Las Vegas October 19-21 at Proof booth 5069.
About Proof
Proof operates identity infrastructure for high-consequence transactions, including WebTrust-audited certificate authority, PKI-anchored credentials and network of more than 8,000 businesses across mortgage, auto, wealth, insurance and enterprise. More than $1 trillion in transactions secured on platform. Proof published x401 as open protocol in June 2026 and is first to put verified legal identity for AI agents into production.
About Circle Internet Group, Inc.
Circle is one of world's leading internet financial platform companies, building foundation of more open global economy through programmable blockchain infrastructure, digital assets, and payment applications. Platform includes world's largest stablecoin network anchored by USDC, Circle Payments Network for global money movement, and Arc, enterprise-grade blockchain designed to become Economic OS for internet.
