Agentic commerce protocols: MCP, UCP, ACP and AP2
MCP, UCP, ACP and AP2 are open protocols that let AI agents use tools, shop, check out and pay for a person. All four depend on clean, structured and current product data, so preparing your catalog is the work that carries across every one of them.
What is agentic commerce?
Section titled “What is agentic commerce?”Agentic commerce is shopping where an AI agent finds, compares and buys products for a person. The agent reads stores, asks questions and can complete a purchase. For that to work across many businesses, agents and stores need shared rules for how they talk to each other.
Those shared rules are protocols. Four open protocols get most of the attention today: MCP, UCP, ACP and AP2. The glossary defines each one in a sentence.
What are MCP, UCP, ACP and AP2?
Section titled “What are MCP, UCP, ACP and AP2?”MCP, UCP, ACP and AP2 each cover a different part of how agents work with businesses. Status is as of October 2026.
| Protocol | Published by | What it covers | Status |
|---|---|---|---|
| MCP, the Model Context Protocol | Created by Anthropic. Now part of the Agentic AI Foundation under the Linux Foundation | Connecting AI applications to outside tools and data | Introduced November 2024. Donated December 2025 |
| UCP, the Universal Commerce Protocol | Google, co-developed with commerce companies including Shopify | Catalog, cart, checkout, identity linking and orders | Launched January 2026 |
| ACP, the Agentic Commerce Protocol | Maintained by OpenAI and Stripe | Letting a buyer’s AI agent complete a purchase with a business | Beta. Announced September 2025 |
| AP2, the Agent Payments Protocol | Created by Google. Contributed to the FIDO Alliance | Payments an agent makes with a person’s verifiable authorization | Version 0.2 released April 2026 |
What is MCP?
Section titled “What is MCP?”MCP, the Model Context Protocol, is an open protocol that connects AI applications to outside tools and data. Anthropic introduced MCP in November 2024. In December 2025 Anthropic donated MCP to the Agentic AI Foundation under the Linux Foundation.
MCP isn’t specific to commerce. An agent uses MCP to call a tool that someone publishes instead of reading their web page. The MCP site has the specification.
What is UCP?
Section titled “What is UCP?”UCP, the Universal Commerce Protocol, is an open standard from Google for agent-led shopping. Google launched UCP in January 2026, co-developed with commerce companies including Shopify.
UCP aims to be a common language for agents and businesses. It covers catalog, cart, checkout, identity linking and orders. The UCP site has the specification.
What is ACP?
Section titled “What is ACP?”ACP, the Agentic Commerce Protocol, lets a buyer’s AI agent complete a purchase with a business. OpenAI and Stripe maintain it. They announced ACP in September 2025 alongside Instant Checkout in ChatGPT.
ACP is marked beta. The ACP site has the specification.
What is AP2?
Section titled “What is AP2?”AP2, the Agent Payments Protocol, covers payments an AI agent makes for a person. Google created AP2 and announced it in September 2025. AP2 uses mandates, which are verifiable digital credentials that record what the person authorized. A merchant or payment provider can check the payment against that approval.
In April 2026 Google released AP2 version 0.2 and contributed AP2 to the FIDO Alliance. The AP2 site has the specification.
What do these protocols mean for merchants?
Section titled “What do these protocols mean for merchants?”Every one of these protocols depends on clean, structured and current product data. A protocol defines how an agent asks a question or places an order. It can’t fix a catalog with missing attributes, stale prices or facts locked in PDFs.
That makes data readiness the work that carries across all four. A store with complete attributes, variant-level detail and current inventory is in a strong position for whichever protocols reach its channels. Is your product data ready for AI agents? covers the common gaps.
Where does Webscale AI fit?
Section titled “Where does Webscale AI fit?”Webscale AI focuses on readiness. Structured first-party catalog data is the foundation these standards need. The Commerce Context Engine is where Webscale AI builds that data from your store, your back office and your experts.
Whether a protocol becomes available in a specific channel depends on how each standard rolls out. These protocols are still changing, so check each one’s site for its current status.
Key takeaways
Section titled “Key takeaways”- MCP connects AI applications to tools and data. UCP, ACP and AP2 focus on shopping, checkout and payments.
- MCP came from Anthropic, UCP and AP2 from Google and ACP from OpenAI and Stripe.
- All four protocols depend on clean, structured and current product data.
- Data readiness is the work that carries across every protocol.
- Each protocol is still evolving, so availability in a given channel depends on how it rolls out.
Frequently asked questions
- What is the difference between UCP and ACP?
- Both let AI agents buy from businesses. UCP comes from Google and covers catalog, cart, checkout, identity linking and orders. ACP is maintained by OpenAI and Stripe and focuses on letting a buyer's AI agent complete a purchase.
- Is MCP a commerce protocol?
- MCP is a general protocol for connecting AI applications to outside tools and data. It isn't specific to commerce, though commerce systems can use it to let agents call their tools.
- What is a mandate in AP2?
- A mandate is a verifiable digital record of what a person authorized. AP2 uses mandates so a merchant or payment provider can check that an agent's payment matches what the person approved.
- Do merchants need to pick one protocol?
- The protocols cover different jobs and are still evolving. Whichever ones reach your channels, each one depends on clean, structured and current product data.