UCP & ACP

The Rise of Agentic Handshakes: Securing Autonomous Transactions

UCPFix Team
Mar 24, 2025
5 min read

What is an Agentic Handshake?

An Agentic Handshake is a multi-step cryptographic verification process where a user’s AI agent identifies itself to a merchant’s server, proves it has a “Consumer Mandate” (permission to buy), and exchanges a secure token to finalize a sale.

Unlike traditional e-commerce, where you “push” your credit card data to a site, the handshake “pulls” a single-use authorization.

The 3 Pillars of Secure Autonomous Shopping

To facilitate these handshakes, the industry has standardized three critical security layers:

  • Delegated Payment Tokens: Through the ACP’s “Delegated Payment Spec,” agents never handle raw credit card numbers. Instead, they use Shared Payment Tokens (SPT)—dynamic, encrypted credentials provided by processors like Stripe or Visa that are restricted by amount, merchant, and expiration date.
  • Consumer Mandates: These are the “rules of engagement” set by the human. A user might tell their agent, “You have a $100 budget for running shoes, only from B-Corp certified brands.” The handshake verifies that the transaction fits within these pre-defined bounds before the merchant can capture funds.
  • Cryptographic Agent ID: To distinguish a helpful shopping agent from a malicious scraper, merchants now use the Web Bot Auth standard. This allows legitimate agents (like ChatGPT or Gemini) to present a verifiable digital signature, ensuring the merchant only accepts “Agent-Initiated” orders from trusted sources.

Why “Agent-Ready” Checkouts are Mandatory

For merchants, failing to support the Agentic Handshake means being excluded from the Zero-click commerce loop. If an agent can’t verify your security credentials in milliseconds, it will simply move to a competitor whose checkout is “Agent-Compliant.”

By 2026, “conversion” isn’t just about convincing a human; it’s about passing the security audit of their digital proxy.

Key Takeaway: The Agentic Handshake is the “HTTPS” of the 2026 commerce world. It provides the trust framework necessary for Autonomous Shopping by combining delegated tokens with strictly enforced consumer mandates.