UCP & ACP

ACP vs. UCP: Choosing the Right Protocol for Your Agentic Strategy

UCPFix Team
Nov 21, 2024
5 min read

UCP: The Execution Layer for Integrated Shopping

UCP is an open-source standard designed to provide a common language between consumer surfaces and business backends. It is built for deep integration with existing retail infrastructure.

  • Merchant-Centric Control: Under UCP, you own your business logic and remain the Merchant of Record, maintaining the customer relationship.
  • Protocol Interoperability: UCP is designed to be vendor-agnostic and is compatible with the Model Context Protocol (MCP) and Agent2Agent (A2A) transports.
  • Native & Embedded Options: It provides an “embedded option” through the Embedded Checkout Protocol (ECP), allowing you to maintain a fully customized checkout experience within the agent’s interface.

ACP: The Decision Layer for Conversational Intent

While UCP focuses on the “how” of the transaction, the Agentic Commerce Protocol (ACP) often centers on the “why” and “what” within AI assistant frameworks. It focuses on the high-level intent—helping an agent decide which product best fits a user’s complex needs.

  • Delegated Authority: ACP emphasizes the agent’s ability to act as a proxy for the human, often utilizing delegated payment tokens to complete tasks across fragmented surfaces.
  • AI-First Orchestration: Where UCP leverages structured Merchant Center data for discovery, ACP often relies on more fluid, conversational reasoning to narrow down choices before initiating a handshake with an execution protocol.

Which One Should You Prioritize?

Most enterprise retailers won’t choose one; they will bridge both. You use ACP to ensure your brand is the “top recommendation” when an agent is brainstorming, and you implement UCP to ensure that once the decision is made, the checkout is seamless, secure, and completed on your terms.

Key Takeaway: ACP wins the mindshare of the AI agent, but UCP wins the transaction. For a complete “Zero-click” strategy, merchants must use ACP-compliant data for discovery and UCP for secure, sovereign execution.