UCP (Universal Commerce Protocol)
UCP, or the Universal Commerce Protocol, is an open standard led by Google with retailers like Shopify, Etsy, Target, and Walmart that lets AI agents discover products, build carts, and check out across many merchants without a custom integration for each. It covers the full shopping lifecycle and carries cryptographic proof of user consent.
Updated June 24, 2026
How does UCP work?
UCP gives agents one standard way to interact with any participating merchant, app, or payment provider. An agent can search products, compare them, build a cart, and check out, with every authorization backed by cryptographic proof that the user consented.
What does UCP cover?
UCP standardizes the whole shopping lifecycle, not just the payment step:
- Discovery and product search
- Comparison across merchants
- Cart and checkout
- Order tracking
- Post-purchase support
Who is behind UCP?
UCP is led by Google and co-developed with retailers including Shopify, Etsy, Wayfair, Target, and Walmart, and endorsed by Mastercard, Visa, Stripe, and American Express among others. It runs over REST and JSON-RPC and is interoperable with the Agent Payments Protocol (AP2), Agent2Agent (A2A), and the Model Context Protocol (MCP).
How is UCP different from ACP?
Both UCP and ACP are open standards for letting AI agents shop on a person's behalf. UCP, led by Google, aims to cover the entire shopping lifecycle across many merchants. ACP, from OpenAI and Stripe, focuses on agent checkout with a business and first shipped as Instant Checkout in ChatGPT.
| Dimension | UCP | ACP |
|---|---|---|
| Led by | Google with major retailers | OpenAI and Stripe |
| Scope | Full shopping lifecycle across merchants | Agent checkout with a business |
| First surface | Any participating agent or app | Instant Checkout in ChatGPT |
| Interoperability | AP2, A2A, MCP | Stripe payment rails |
UCP and ACP organize agentic commerce around merchants and platforms. They sit alongside the open machine-payment protocols, x402 and MPP, that let agents pay any service directly. Together they form the wider map of open agentic commerce.
Frequently Asked Questions
- What does UCP stand for?
- UCP stands for Universal Commerce Protocol. It is an open standard, led by Google, that lets AI agents discover products and check out across many merchants through one integration.
- Who created UCP?
- UCP was co-developed by Google with retailers including Shopify, Etsy, Wayfair, Target, and Walmart, and endorsed by payment networks such as Mastercard, Visa, and American Express.
- Is UCP the same as ACP?
- No. Both let agents shop for people, but UCP is a Google-led standard covering the full shopping lifecycle across merchants, while ACP is an OpenAI and Stripe standard focused on agent checkout.
- How does UCP relate to MCP and AP2?
- UCP is interoperable with them. MCP connects agents to tools, AP2 handles agent payments, and UCP standardizes the commerce lifecycle on top.