What is the Universal Commerce Protocol (UCP)?
Last verified 2026-08-30The Universal Commerce Protocol (UCP) is an open standard for agentic commerce launched by Google on 11 January 2026 and co-developed with Shopify, Etsy, Wayfair, Target and Walmart, with endorsements from more than 20 organizations including Visa, Mastercard, Stripe and American Express. It covers the full shopping journey, from discovery and checkout to post-purchase support, and gives agents, businesses, payment service providers and credential providers a common language. UCP is transport-agnostic (REST APIs, MCP or A2A) and is designed to be compatible with A2A, AP2 and MCP. At launch, Google said UCP would soon power agentic checkout on AI Mode and the Gemini app, where the retailer would remain the seller of record. The specification is open source under Apache 2.0 on GitHub; the latest reviewed release is v2026-08-25.
Key facts
| Author / steward | Google and Shopify (with Etsy, Wayfair, Target, Walmart) |
|---|---|
| Announced | 2026-01-11 |
| License | Apache 2.0 |
| Governance | Open-source project co-developed by Google, Shopify, Etsy, Wayfair, Target and Walmart; specification maintained on GitHub (Universal-Commerce-Protocol/ucp) |
| Scope | Open standard for agentic commerce across the full shopping journey (discovery, buying, post-purchase); Google announced a future checkout rollout in AI Mode and the Gemini app, with the retailer remaining seller of record |
| Transport | Transport-agnostic: capabilities served over REST APIs, MCP or A2A |
| Payment | Payment Token Exchange capability between PSPs and credential providers; Google Pay announced for the initial checkout rollout and PayPal as a future option; supports AP2 mandates and verifiable credentials |
| Maturity | beta |
What makes it distinctive
- Launched by Google on 11 January 2026, co-developed with Shopify, Etsy, Wayfair, Target and Walmart
- Endorsed by more than 20 organizations, including Adyen, American Express, Best Buy, Flipkart, Mastercard, Stripe, Visa and Zalando
- Covers the full shopping journey: discovery, checkout and post-purchase support
- Transport-agnostic: capabilities served over REST APIs, MCP or A2A; compatible with A2A, AP2 and MCP
- Open source under Apache 2.0 on GitHub; latest specification release v2026-08-25
- The August 2026 release adds multi-vertical foundations, location capabilities and grocery-ready quantities
- The August 2026 release adds vendor-neutral 3DS2 flows, split and deferred payments, granular consent and a loyalty extension
- Google announced that UCP would power a future agentic checkout rollout in AI Mode and the Gemini app; the retailer remains seller of record
How UCP works
UCP gives platforms (AI agents and apps), businesses, payment service providers and credential providers a common language. Its architecture is composable: businesses implement Capabilities and declare them in a standardized profile, which platforms discover autonomously and configure themselves against, without one-off integrations. The initial release focuses on four capabilities: Checkout (cart management, tax calculation, flows with or without a human in the loop), Identity Linking (OAuth 2.0 authorization to act on a user’s behalf), Order (webhook-based lifecycle events: shipped, delivered, returned) and Payment Token Exchange (secure token exchange between PSPs and credential providers). Extensions such as discounts and fulfillment add features without bloating the core definitions.
Specification and governance
The specification is published at ucp.dev and on GitHub under Apache 2.0, with SDKs, samples and conformance tests in companion repositories. The latest reviewed release is v2026-08-25. It adds multi-vertical structures, grocery readiness, vendor-neutral 3DS2 flows, structured request constraints, split and scheduled payments, and changes to consent and loyalty. UCP was co-developed by Google with Shopify, Etsy, Wayfair, Target and Walmart, and endorsed at launch by 20+ organizations including Adyen, American Express, Best Buy, Flipkart, Mastercard, Stripe, Visa and Zalando.
How UCP fits the stack
UCP is transport-agnostic: capabilities can be served over REST APIs, MCP or A2A, and the protocol is explicitly compatible with AP2 (including AP2 mandates and verifiable credentials for security). Against ACP, the overlap is in commerce operations; the current documented difference is scope (a broader journey in UCP versus product discovery with merchant-run checkout in ChatGPT) and surface (Google AI Mode and Gemini versus ChatGPT). See ACP vs UCP.
Limitations and open questions
The first consumer-facing deployment announced is checkout on eligible Google product listings in AI Mode and the Gemini app for eligible US retailers, with Google Pay at launch and PayPal announced; Google stated global expansion would follow in the coming months. UCP is young (first release January 2026) and its real-world merchant coverage is still building. As with all of these standards, verify current deployment status against primary sources before making integration decisions.
Who should care
Retailers that sell through Google surfaces, platforms building agent experiences that need standardized merchant access, and PSPs/credential providers interested in the Payment Token Exchange capability. The adoption tracker lists verified supporters.