feat(ecp): per checkout transport configs; ECP support + delegation confirmation #80
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Adds services to checkout response ucp metadata, enabling per-session
transport configuration with typed config. This allows businesses to
confirm ECP availability and specify allowed delegations on a
per-checkout basis.
Changes:
- Add services to response_checkout_schema in ucp.json
- Add response_schema variant to service.json with typed config support
- Add embedded_config.json schema defining delegations array
- Update embedded-checkout.md with two-level discovery model
With this in place, response now carries..
{
"id": "checkout_abc123",
"continue_url": "https://merchant.example.com/checkout/abc123",
"ucp": {
"version": "2026-01-11",
"services": {
"dev.ucp.shopping": [{
"version": "2026-01-11",
"transport": "embedded",
"config": {
"delegations": ["payment.credential", "fulfillment.address_change"]
}
}]
},
"payment_handlers": {...}
}
}
igrigorik
changed the title
|
Note: 81a5ca6 is adding noise because we haven't regenerated spec/* files form the latest source/* in working-draft. |
lemonmade
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lemonmade
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Left a few questions/ requests, but otherwise LGTM 👍
| "$ref": "https://ucp.dev/schemas/shopping/payment.update_req.json" | ||
| }, | ||
| "payment_complete_request": { | ||
| "$ref": "https://ucp.dev/schemas/shopping/payment.complete_req.json" |
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Is this change from your PR? Looks unrelated.
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Yeah, this: #80 (comment)
I can rebase once that's fixed, or we land both.
- Rename `delegations` to `delegate` for consistency with ec.ready
- Add typed config to business_schema (not platform_schema)
- Clarify that config.delegate in responses confirms accepted
delegations (intersection of requested and allowed)
| "rest": { | ||
| "schema": "https://ucp.dev/services/shopping/rest.openapi.json", | ||
| "endpoint": "https://merchant.example.com/ucp/v1" | ||
| "dev.ucp.shopping": [ |
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While re-reviewing this, I noticed that we still have some references to services[\"dev.ucp.shopping\"].rest.endpoint in the REST/ MCP specs. @raginpirate I assume those should have been updated to something like services[\"dev.ucp.shopping\"][transport=rest].endpoint as part of your change to align all the DNS-namespaced concepts in UCP?
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Yeah, we need a thorough scrub to fix all the outdated examples and references. Separate from this PR though.
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Let me validate what might have been missed here... so many doc changes in the last PR 😢
3 participants
Adds
servicesto checkout responseucpmetadata, enabling per-session transport configuration with typed config. This allows businesses to confirm ECP availability and specify allowed delegations on a per-checkout basis.Problem: Previously, ECP availability was binary — if a business advertised
embeddedtransport in service discovery, all checkouts were assumed to support ECP with delegations negotiated at runtime. This didn't account for cart contents, agent authorization levels, or business policy that may restrict ECP or specific delegations for certain sessions.Solution: Two-level discovery model:
/.well-known/ucp): Declares business supports ECPucp.services): Confirms availability and allowed delegations for this sessionKey changes
servicestoresponse_checkout_schemainucp.jsonresponse_schemavariant toservice.jsonwith typed config supportembedded_config.jsonschema definingdelegationsarrayembedded-checkout.mdwith two-level discovery modelExample response:
{ "ucp": { "version": "2026-01-11", "services": { "dev.ucp.shopping": [{ "version": "2026-01-11", "transport": "embedded", "config": { "delegations": ["payment.credential", "fulfillment.address_change"] // <-- NEW } }] }, "payment_handlers": {...} } "id": "checkout_abc123", ... // rest of checkout response "continue_url": "https://merchant.example.com/checkout/abc123", }Type of change
Checklist: