Know Your Agent

What Know Your Agent Means

Know Your Agent (KYA) is the payments industry’s umbrella framework for verifying that an AI agent is authorized to transact on behalf of a human. At its core, KYA answers a fundamental question for merchants and financial institutions: “Is this agent allowed to spend my money, and can the merchant trust it?”

Think of KYA as the digital equivalent of a power of attorney. Just as a human might authorize a lawyer to sign a contract on their behalf, KYA provides the technical infrastructure for a human to authorize an AI agent to initiate a payment. Crucially, KYA is not a single protocol. It is a layered framework where multiple protocols each solve a different piece of the puzzle: agent identity, user mandate authorization, payment instrument verification, and audit trails.

The Composition Model: How the Protocols Layer

To understand how KYA works in practice, consider a simple, everyday scenario: A user tells their AI assistant, “Buy me running shoes under $100 from Nike.” For this transaction to succeed, the assistant must prove to Nike’s checkout system that it is legitimate and authorized.

In a typical production stack, these protocols do not compete; they compose to form a complete security chain. The assistant uses Visa’s Trusted Agent Protocol (TAP) to sign its identity at the HTTP layer. It then presents a Google Agent Payments Protocol (AP2) Cart Mandate to prove the user authorized this specific purchase. The actual payment is carried out via a Mastercard Agent Pay network token, and the entire process is tied together by a Verifiable Intent record that serves as a shared audit trail.

This layered approach ensures that identity, intent, and action are all cryptographically verified before any funds move.

Five Approaches to the Same Problem

While the industry is converging, several distinct approaches have emerged to address the KYA challenge:

• KYAPay: Introduced by Skyfire, this identity-linked payment protocol uses standards-compliant JSON Web Tokens (JWTs) in three forms — KYA (identity), Pay (payment), and KYA+Pay (combined). It serves as a lighter-weight alternative for merchants that already verify JWTs.
• Trusted Agent Protocol (TAP): Developed by Visa with Cloudflare, this approach uses Ed25519 cryptographic signatures over HTTP requests, aligned with RFC 9421. It conveys agent intent, consumer recognition, and payment information.
• Agent Payments Protocol (AP2): Google’s protocol uses cryptographically-signed Mandates — Intent Mandates for delegated authority and Cart Mandates for specific purchase authorization — as tamper-proof digital contracts. Launched with 60+ partners.
• Verifiable Intent: Co-developed by Mastercard and Google, this creates a tamper-resistant cryptographic record linking consumer identity, agent instructions, and the transaction. Built on FIDO Alliance, EMVCo, IETF, and W3C specs, with Selective Disclosure for privacy.
• x401: Published by Proof, this open HTTP protocol extends the standard 401 error into an agent-verification challenge. The consumer authenticates via device biometric and signs the exact transaction terms — if the agent changes anything, the signature breaks.

Fraud overlays from vendors like Forter, Riskified, and HUMAN consume all of these signals for real-time risk scoring.

Three Things KYA Is Not

It is easy to confuse KYA with adjacent security concepts. Three distinctions matter:

• It is not just agent identity: Agent identity answers “who is this agent?” through registration and authentication. KYA goes further to answer “is this agent authorized to spend on behalf of this user?” The two pair up, but they solve different problems.
• It is not just permission tokens: Permission tokens define spending limits, approved merchants, and expiry dates. KYA verifies the agent’s fundamental authorization to initiate a transaction at all — before any spending limit is checked.
• It is not plain KYC: Know Your Customer (KYC) verifies the identity of the human customer during onboarding. KYA extends that verification chain to the AI agent acting on the human’s behalf, every time it tries to pay.

Where It Stands

Currently, no single KYA standard has been ratified by a global standards body. But the ecosystem is converging fast. Google donated its AP2 protocol to the FIDO Alliance in 2026. Visa has committed to aligning TAP with the IETF, OpenID Foundation, and EMVCo. Mastercard open-sourced Verifiable Intent for ecosystem-wide adoption. And Proof’s x401 has entered production with support from Visa, Circle, and Okta.

The remaining open question is interoperability: can these protocols work together seamlessly so that a single agent can transact across any merchant, any payment network, and any identity provider? That is the work in front of the industry now.