generated: '2026-07-18'
method: searched
source: https://chill.com/llms.txt + https://chill.com/.well-known/ucp
summary: >-
  Cross-cutting conventions for agent interaction with the Chill.com Shopify store.
  The store is agent-native: it publishes an llms.txt agent guide and implements
  the Universal Commerce Protocol (UCP) over an MCP endpoint.
authentication:
  style: >-
    Read-only browsing requires no auth; transactional (cart/checkout) tools use
    Shopify Customer Account OAuth 2.0 + OIDC. See authentication/chill-authentication.yml.
transport:
  protocol: mcp
  endpoint: https://chill.com/api/ucp/mcp
  format: JSON-RPC 2.0
  discovery: GET /.well-known/ucp returns the UCP merchant profile
agent_commerce:
  protocol: Universal Commerce Protocol (UCP)
  spec: https://ucp.dev
  buyer_approval_invariant: >-
    Agents MUST NOT complete payment without explicit, contemporaneous buyer consent.
    Where consent cannot be obtained at the moment of payment, route through the Shop
    skill (https://shop.app/SKILL.md) / Shop Pay instead.
  typical_flow: [discover, search_catalog, create_cart, create_checkout, update_checkout, complete_checkout]
  buyer_context: Pass context.address_country and context.currency for accurate pricing and availability
rate_limiting:
  signaled_via: HTTP 429
  guidance: MCP endpoint is rate-limited per IP; back off on 429 responses
versioning:
  scheme: date-based UCP protocol versions
  current: '2026-04-08'
  supported: ['2026-04-08', '2026-01-23']
read_only_browsing:
  product_page: GET /products/{handle}
  product_json: GET /products/{handle}.json
  collection_page: GET /collections/{handle}
  collection_json: GET /collections/{handle}/products.json
  all_products: GET /collections/all
idempotency:
  documented: false
  note: No idempotency-key contract is published for the storefront or UCP MCP endpoint.
cross_links:
  authentication: authentication/chill-authentication.yml
  scopes: scopes/chill-scopes.yml
  mcp: mcp/chill-mcp.yml
  well_known: well-known/chill-well-known.yml