UCP Implementation: Checklist and Go-Live Validation

Use this page as your implementation reference when building UCP from scratch or auditing an existing integration. Work through the checklist top-to-bottom — each section depends on the ones before it. The Readiness Score tool maps directly to these checks and will surface any gaps automatically.

Implementation checklist

Pre-implementation

	Check
☐	Domain has HTTPS configured
☐	Google Merchant Center account is active (if using the Google path)
☐	Product feed exists in a machine-readable format (JSON or XML)
☐	Payment processor (PSP) integration is already in place
☐	Policy pages are live: returns, privacy, and shipping

Capability discovery

	Check
☐	`/.well-known/ucp` is hosted at the domain root
☐	File is valid JSON — no trailing commas, correct syntax
☐	Response header is `Content-Type: application/json`
☐	File is publicly accessible with no authentication required
☐	Both `product_catalog` and `checkout` capabilities are declared

Catalog

	Check
☐	`GET /ucp/products` returns valid product objects
☐	Each product has `id`, `name`, `description`, `price`, and `availability`
☐	Products with multiple options have explicit variant objects
☐	Prices are in the smallest currency unit (cents, not dollars)
☐	Availability statuses use the correct enum values
☐	Product images are absolute HTTPS URLs

Checkout

	Check
☐	`POST /ucp/checkout` accepts cart items and shipping address, returns shipping options
☐	`POST /ucp/checkout/:id/confirm` accepts a payment token and places the order
☐	Inventory is re-validated at confirmation time (not just at cart creation)
☐	Structured error responses are returned for payment failure, out-of-stock, and invalid address
☐	Idempotency keys are supported to prevent duplicate orders
☐	`expires_at` is included in the cart creation response

Post-purchase

	Check
☐	`GET /ucp/orders/:id` returns current order status
☐	Fulfillment and tracking updates are sent via webhook
☐	Returns or cancellations endpoint is available (recommended)

Implementation steps

Implement capability discovery

Start with /.well-known/ucp. This is the fastest path to partial readiness — even before your catalog and checkout are live, publishing a manifest with your planned endpoints signals to Google and other agents that your domain is UCP-capable.See: UCP capability discovery

Expose your catalog endpoint

Build GET /ucp/products. Focus on getting the data shape right: explicit variant objects for every product with options, prices in cents, and correct availability enum values. Run the Readiness Score after each iteration.See: Product catalog endpoint

Implement checkout endpoints

Build cart creation (POST /ucp/checkout) and order confirmation (POST /ucp/checkout/:id/confirm). Integrate your PSP for payment token processing. Return structured errors for every failure mode.See: Checkout and payments

Add post-purchase hooks

Implement GET /ucp/orders/:id for order status lookups. Configure fulfillment webhooks so customers receive tracking updates inside the AI conversation without leaving it.

Validate and go live

Run the full Readiness Score audit. Fix any critical or high-severity gaps before submitting. If you’re using the Google path, submit your updated Merchant Center feed and check Diagnostics for UCP-specific errors.

curl -X POST https://asva-ai.com/api/audit \
  -H "Authorization: Bearer $ASVA_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"domain": "yourstore.com"}'

Testing commands

Run these commands manually to verify each endpoint before using the automated audit:

# Confirm the manifest is reachable and returns valid JSON
curl -I https://yourstore.com/.well-known/ucp
curl https://yourstore.com/.well-known/ucp | python3 -m json.tool

# Test the catalog endpoint
curl https://yourstore.com/ucp/products

# Dry-run a checkout request
curl -X POST https://yourstore.com/ucp/checkout \
  -H "Content-Type: application/json" \
  -d '{"items":[{"product_id":"prod_123","quantity":1}],"dry_run":true}'

# Check order status (replace with a real order ID)
curl https://yourstore.com/ucp/orders/order_abc123

Common errors and fixes

Error	Likely cause	Fix
`/.well-known/ucp` returns 404	File not at domain root, or server blocks `.well-known` paths	Move file to root domain; add explicit server route
`Content-Type: text/plain`	Host defaults to plain text for unknown extensions	Set `Content-Type: application/json` in server config or use a route handler
Catalog returns empty `products` array	Endpoint not wired to your data source	Connect to live inventory and verify query returns results
Checkout returns 500	PSP credentials missing or payment token invalid	Check environment variables; verify PSP test/live mode
Price mismatch between catalog and checkout	Prices cached too long or expressed in dollars instead of cents	Reduce cache TTL to 5 minutes; confirm all prices are in smallest currency unit
Variant ID not found at checkout	Variant ID in catalog differs from ID passed in checkout	Ensure `variant_id` in checkout matches `id` in the variant object from your catalog

Validation reference

Check	Tool	API endpoint
Full readiness audit	Readiness Score	`POST /api/audit`
Manifest generation and validation	Manifest Generator	`POST /api/manifest`
Feed quality check	Built into Readiness Score	—
Manifest-only validation	Manifest Generator	`POST /api/manifest/validate`

Choose your implementation path

Google Merchant Center

Recommended for most brands. Builds on your existing Merchant Center feed.

Shopify

Native UCP on Shopify — fastest path for Shopify merchants.

Custom or headless

Build UCP endpoints on any backend stack. Full control over data and logic.

Agency rollout

Multi-client playbook for agencies implementing UCP at scale.

Get Started

UCP

ACP

Attribution

Guides

UCP Implementation: Checklist and Go-Live Validation

Implementation checklist

Pre-implementation

Capability discovery

Catalog

Checkout

Post-purchase

Implementation steps

Testing commands

Common errors and fixes

Validation reference

Choose your implementation path

Google Merchant Center

Shopify

Custom or headless

Agency rollout

​Implementation checklist

​Pre-implementation

​Capability discovery

​Catalog

​Checkout

​Post-purchase

​Implementation steps

​Testing commands

​Common errors and fixes

​Validation reference

​Choose your implementation path

Google Merchant Center

Shopify

Custom or headless

Agency rollout

Implementation checklist

Pre-implementation

Capability discovery

Catalog

Checkout

Post-purchase

Implementation steps

Testing commands

Common errors and fixes

Validation reference

Choose your implementation path