generated: '2026-07-18'
method: searched
source: https://casper.com/llms.txt + https://casper.com/.well-known/ucp
notes: >-
  Cross-cutting agent/commerce semantics for the casper.com Shopify storefront, as
  published in its llms.txt agent instructions and UCP merchant profile.
authentication:
  style: Shopify Customer Account API OIDC/OAuth2 (authorization code + PKCE); anonymous read for public product/collection JSON.
  reference: authentication/casper-authentication.yml
agent_access:
  llms_txt: https://casper.com/llms.txt
  agents_md: https://casper.com/agents.md
  protocol: Universal Commerce Protocol (UCP, https://ucp.dev)
  ucp_versions: ['2026-04-08', '2026-01-23']
  mcp_endpoint: https://casper.com/api/ucp/mcp
  discovery: https://casper.com/.well-known/ucp
human_in_the_loop:
  required_for: [checkout payment completion]
  rule: Agents must not complete payment without explicit, contemporaneous buyer approval.
rate_limiting:
  signal: HTTP 429
  policy: Per-IP rate limiting on the MCP endpoint; agents must back off on 429.
  reference: null
buyer_context:
  params: [context.address_country, context.currency]
  purpose: Required for accurate pricing and availability.
read_only_browsing:
  auth_required: false
  endpoints:
  - GET /collections/all
  - GET /products/{handle}.json
  - GET /collections/{handle}/products.json
  - GET /search?q={query}&type=product
  - GET /sitemap.xml