The Protocol Wars: UCP vs. ACP vs. MCP

The Protocol Wars: UCP vs. ACP vs. MCP

Three Standards, One Infrastructure Battle

Three competing protocols are racing to become the standard for AI agent commerce. Google’s Universal Commerce Protocol (UCP) covers the full shopping journey. OpenAI and Stripe’s Agentic Commerce Protocol (ACP) focuses on checkout. Anthropic’s Model Context Protocol (MCP) provides general-purpose AI connectivity.

The winner defines how AI agents interact with commerce for the next decade. Merchants face fragmentation now, consolidation later.

This is TCP/IP for agentic commerce.

Competing Standards for Agentic Commerce

Google: Universal Commerce Protocol (UCP)

  • Full journey coverage (Discovery → Checkout → Support)
  • 50B+ products already indexed
  • Retailer stays merchant of record
  • Works with existing ad infra

Launch Partners (20+): Shopify, Etsy, Wayfair, Target, Walmart, BigCommerce

OpenAI/Stripe: Agentic Commerce Protocol (ACP)

  • Checkout-focused
  • Open source (Apache 2.0)
  • Works with any payment processor
  • Transaction fee on purchase
  • Still building merchant data feeds

Partners: Stripe, Etsy, 1M+ Shopify merchants (coming soon)

Anthropic: Model Context Protocol (MCP)

  • General-purpose AI connectivity
  • Broader infrastructure layer
  • Not commerce-specific
  • Compatible with UCP/ACP
  • Foundation for commerce protocols

Head-to-Head Analysis

Dimension Google UCP OpenAI/Stripe ACP Anthropic MCP
Scope Full journey (discover → return) Checkout only General AI connectivity
Monetization Ads (CPC) Transaction fee N/A (infra layer)
License Proprietary Apache 2.0 (open source) Open source
Data Readiness 50B+ products indexed Building merchant feeds Connects to any data source
Key Partners Shopify, Walmart, Target, 20+ Stripe, Etsy, Shopify (coming) Broad AI ecosystem

The Real Battle

This is a business model war disguised as a protocol war. Google needs ads to survive; OpenAI is betting on transaction fees. The protocol that wins merchant adoption defines the economics of agentic commerce for the next decade.


This is part of a comprehensive analysis. Read the full analysis on The Business Engineer.

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