Universal Commerce
Protocol
The common language for platforms, agents and businesses.
UCP defines building blocks for agentic commerce—from discovering and buying to post purchase experiences—allowing the ecosystem to interoperate through one standard, without custom builds.
Co-developed and adopted by industry leaders
UCP was built by the industry, for the industry to solve for fragmented commerce journeys that lead to abandoned carts and frustrated shoppers, and enable agentic commerce.
Google
Shopify
Etsy
Wayfair
Target
Walmart
Built for flexibility, security, and scale
Agentic commerce demands interoperability. UCP is built on industry standards — REST and JSON-RPC transports; Agent Payments Protocol (AP2), Agent2Agent (A2A), and Model Context Protocol (MCP) support built-in — so different systems can work together without custom integration.
Scalable and universal
Surface-agnostic design that can scale to support any commerce entity (from small businesses to enterprise scale) and all modalities (chat, visual commerce, voice, etc).
Businesses at the center
Built to facilitate commerce, ensuring retailers retain control of their business rules and remain the Merchant of Record with full ownership of the customer relationship.
Open and extensible
Open and extensible by design, enabling development of community-driven capabilities and extensions across verticals.
Secure and private
Built on proven security standards for account linking (OAuth 2.0) and secure payment (AP2) via payment mandates and verifiable credentials.
Frictionless payments
Open wallet ecosystem with interoperability between providers to ensure buyers can pay with their preferred payment methods.
See it in action
UCP is designed to facilitate the entire commerce lifecycle, from initial product discovery and search to final sale and post-purchase support. The protocol's initial launch focuses on three core capabilities: Checkout, Identity Linking, and Order Management.
Checkout
Support complex cart logic, dynamic pricing, tax calculations, and more across millions of businesses through unified checkout sessions.
Learn more
{
"ucp": { ... },
"id": "chk_123456789",
"status": "ready_for_complete",
"currency": "USD",
"buyer": {
"email": "e.beckett@example.com",
"first_name": "Elisa",
"last_name": "Beckett"
},
"line_items": [
{
"id": "li_1",
"item": {
"id": "item_123",
"title": "Monos Carry-On Pro suitcase",
"price": 26550
},
"quantity": 1,
...
}
],
"totals": [ ... ],
"links": [ ... ],
"payment": { ... },
"fulfillment": {
"methods": [
{
"id": "method_1",
"type": "shipping",
"line_item_ids": ["li_1"],
"selected_destination_id": "dest_1",
"destinations": [
{
"id": "dest_1",
"full_name": "Elisa Beckett",
"street_address": "1600 Amphitheatre Pkwy",
"address_locality": "Mountain View",
"address_region": "CA",
"postal_code": "94043",
"address_country": "US"
}
],
"groups": [
{
"id": "group_1",
"line_item_ids": ["li_1"],
"selected_option_id": "free-shipping",
"options": [
{
"id": "free-shipping",
"title": "Free Shipping",
"totals": [ {"type": "total", "amount": 0} ]
}
]
}
]
}
]
}
}
Identity Linking
OAuth 2.0 standard enables agents to maintain secure, authorized relationships without sharing credentials.
Learn more
Sample of /.well-known/oauth-authorization-server
{
"issuer": "https://example.com",
"authorization_endpoint": "https://example.com/oauth2/authorize",
"token_endpoint": "https://example.com/oauth2/token",
"revocation_endpoint": "https://example.com/oauth2/revoke",
"scopes_supported": [
"ucp:scopes:checkout_session",
],
"response_types_supported": [
"code"
],
"grant_types_supported": [
"authorization_code",
"refresh_token"
],
"token_endpoint_auth_methods_supported": [
"client_secret_basic"
],
"service_documentation": "https://example.com/docs/oauth2"
}
Order
From purchase confirmation to delivery. Real-time webhooks power status updates, shipment tracking, and return processing across every channel.
Learn more
{
"ucp": { ... },
"id": "order_123456789",
"checkout_id": "chk_123456789",
"permalink_url": ...,
"line_items": [ ... ],
"fulfillment": {
"expectations": [
{
"id": "exp_1",
"line_items": [{ "id": "li_1", "quantity": 1 }],
"method_type": "shipping",
"destination": {
"full_name": "Elisa Beckett",
"street_address": "1600 Amphitheatre Pkwy",
"address_locality": "Mountain View",
"address_region": "CA",
"postal_code": "94043",
"address_country": "US"
},
"description": "Arrives in 2-3 business days",
"fulfillable_on": "now"
}
...
],
"events": [
{
"id": "evt_1",
"occurred_at": "2026-01-11T10:30:00Z",
"type": "delivered",
"line_items": [{ "id": "li_1", "quantity": 1 }],
"tracking_number": "123456789",
"tracking_url": "https://fedex.com/track/123456789",
"description": "Delivered to front door"
}
]
},
"adjustments": [
{
"id": "adj_1",
"type": "refund",
"occurred_at": "2026-01-12T14:30:00Z",
"status": "completed",
"line_items": [{ "id": "li_1", "quantity": 1 }],
"amount": 26550,
"description": "Defective item"
}
],
"totals": [ ... ]
}
Power native checkout
Integrate and negotiate directly with a seller's checkout API to power native UI and workflows for your platform.
See how it works
Embed business checkout
Embed and render business checkout UI to support complex checkout flows, with advanced capabilities like bidirectional communication, and payment and shipping address delegation.
Learn moreDesigned for the entire commerce ecosystem
For Developers
Build the future of commerce on an open foundation. Join our community in evolving an open-source standard designed for the next generation of digital commerce.
View the technical spec
For Businesses
UCP empowers retailers to meet customers wherever they are—AI assistants, shopping agents, embedded experiences—without rebuilding your checkout for each. You remain the Merchant of Record and your business logic stays intact.
Integrate with UCP
For AI Platforms
Simplify business onboarding with standardized APIs and provide your audience with an integrated shopping experience. Compatible with MCP, A2A, and existing agent frameworks.
Learn more about UCP core concepts
For Payment Providers
Universal payments that are provable—every authorization backed by cryptographic proof of user consent. Open, modular payment handler design enables open interoperability and choice of payment methods.
Learn more about UCP and AP2Endorsed across the ecosystem
Adyen
Amex
Ant International
Best Buy
Carrefour
Chewy
Commerce
Flipkart
Gap
Kroger
Lowe's
Macy's
Mastercard
Paypal
Salesforce
Sephora
Shopee
Stripe
The Home Depot
Ulta
Visa
Worldpay
Zalando
Adyen
Amex
Ant International
Best Buy
Carrefour
Chewy
Commerce
Flipkart
Gap
Kroger
Lowe's
Macy's
Mastercard
Paypal
Salesforce
Sephora
Shopee
Stripe
The Home Depot
Ulta
Visa
Worldpay
Zalando
Get started today
UCP is an open standard designed to let AI agents, apps, businesses, and payment providers interact seamlessly without needing custom, one-off integrations for every connection. We actively seek your feedback and contributions to help build the future of commerce.
The complete technical specification, documentation, and reference implementations are hosted in our public GitHub repository.
