UCP employs a server-selects architecture where the business (server) chooses the protocol version and capabilities from the intersection of both parties' capabilities. Your business profile will enable Google to efficiently negotiate capabilities with your server.
For more information about capability discovery, governance, and negotiation, see the UCP specification .
Create a business profile
Publish your business profile at /.well-known/ucp. For example:
{
"ucp": {
"version": "2026-01-11",
"services": {
"dev.ucp.shopping": {
"version": "2026-01-11",
"spec": "https://ucp.dev/specification/overview",
"rest": {
"schema": "https://ucp.dev/services/shopping/rest.openapi.json",
"endpoint": "https://business.example.com/ucp/v1"
},
"mcp": {
"schema": "https://ucp.dev/services/shopping/mcp.openrpc.json",
"endpoint": "https://business.example.com/ucp/mcp"
},
"a2a": {
"endpoint": "https://business.example.com/.well-known/agent-card.json"
},
"embedded": {
"schema": "https://ucp.dev/services/shopping/embedded.openrpc.json"
}
}
},
"capabilities": [
{
"name": "dev.ucp.shopping.checkout",
"version": "2026-01-11",
"spec": "https://ucp.dev/specification/checkout",
"schema": "https://ucp.dev/schemas/shopping/checkout.json"
},
{
"name": "dev.ucp.shopping.fulfillment",
"version": "2026-01-11",
"spec": "https://ucp.dev/specification/fulfillment",
"schema": "https://ucp.dev/schemas/shopping/fulfillment.json",
"extends": "dev.ucp.shopping.checkout"
},
{
"name": "dev.ucp.shopping.discount",
"version": "2026-01-11",
"spec": "https://ucp.dev/specification/discount",
"schema": "https://ucp.dev/schemas/shopping/discount.json",
"extends": "dev.ucp.shopping.checkout"
}
]
},
"payment": {
"handlers": [
{
"id": "business_tokenizer",
"name": "com.example.business_tokenizer",
"version": "2026-01-11",
"spec": "https://example.com/specs/payments/business_tokenizer",
"config_schema": "https://example.com/specs/payments/merchant_tokenizer.json",
"instrument_schemas": [
"https://ucp.dev/schemas/shopping/types/card_payment_instrument.json"
],
"config": {
"type": "CARD",
"tokenization_specification": {
"type": "PUSH",
"parameters": {
"token_retrieval_url": "https://api.psp.example.com/v1/tokens"
}
}
}
}
]
},
"signing_keys": [
{
"kid": "business_2025",
"kty": "EC",
"crv": "P-256",
"x": "WbbXwVYGdJoP4Xm3qCkGvBRcRvKtEfXDbWvPzpPS8LA",
"y": "sP4jHHxYqC89HBo8TjrtVOAGHfJDflYxw7MFMxuFMPY",
"use": "sig",
"alg": "ES256"
}
]
}
The ucp object contains protocol metadata: version, services, and capabilities. Payment configuration is a sibling — see Payment Architecture . The signing_keys array contains public keys (JWK format) used to verify signatures on webhooks and other authenticated messages from your servers.