generated: '2026-08-26'
method: probed
source: https://shop.oatside.com/api/ucp/mcp, https://shop.oatside.com/agents.md, https://shop.oatside.com/policies/refund-policy
api: Oatside SG Storefront UCP / MCP
protocol:
  style: JSON-RPC 2.0 over HTTP POST (Model Context Protocol)
  content_type: application/json
  accept: application/json, text/event-stream
  mcp_protocol_version: '2024-11-05'
  ucp_api_version: '2026-04-08'
authentication:
  style: anonymous transport + required UCP agent profile URI
  detail: authentication/oatside-authentication.yml
money:
  representation: >-
    Integer minor units paired with an ISO 4217 currency code, e.g.
    {"amount": 600, "currency": "USD"} is $6.00. Documented in the description of every
    price-bearing tool.
  zero_decimal_note: Zero-decimal currencies such as JPY are already whole units.
identifiers:
  style: Shopify global IDs
  example: gid://shopify/Checkout/abc123
  note: Documented in the get_checkout / update_checkout inputSchema id descriptions.
buyer_context:
  parameters:
  - context.address_country
  - context.currency
  note: agents.md instructs agents to pass buyer context for accurate pricing and availability.
idempotency:
  supported: false
  evidence: >-
    No Idempotency-Key header, no idempotency_key parameter and no request-token field
    appears in any of the 13 tool inputSchemas, and neither agents.md nor the UCP merchant
    profile documents one.
  mitigation: >-
    Safety on repeated writes is instead structural: cart and checkout are addressable
    resources created once and then updated by id, so a retried create_cart yields a new
    cart rather than a duplicate order, and only complete_checkout is terminal — and that
    one requires human approval.
  status: absent
pagination:
  supported: unknown
  evidence: >-
    search_catalog and lookup_catalog inputSchemas were captured verbatim in
    mcp/oatside-ucp-mcp-tools.json; no cursor/page/limit convention is documented in
    agents.md.
tracing:
  request_id_header: x-request-id
  evidence: Observed on the live MCP response on 2026-08-26.
versioning:
  header: x-shopify-ucp-mcp-api-version
  current: '2026-04-08'
  detail: lifecycle/oatside-lifecycle.yml
errors:
  envelope: JSON-RPC 2.0 error object with a UCP-specific data.code
  detail: errors/oatside-problem-types.yml
rate_limits:
  detail: rate-limits/oatside-rate-limits.yml
dry_run_mode:
  supported: false
  note: >-
    No dry-run/preview flag in any tool schema. The closest equivalent is that
    create_checkout and update_checkout return full totals, taxes and discounts before
    complete_checkout is called, so an agent can quote a final price without committing.
reversibility:
  status: verified
  summary: >-
    Both pre-purchase write surfaces have an explicit reversal tool, and the post-purchase
    return path has a published window.
  surfaces:
  - surface: cart
    write_operations:
    - create_cart
    - update_cart
    reversal_operation: cancel_cart
    window: >-
      Not stated. No expiry for a cart is published in agents.md, the UCP profile or the
      tool descriptions.
    grade: documented
    source: https://shop.oatside.com/api/ucp/mcp
  - surface: checkout
    write_operations:
    - create_checkout
    - update_checkout
    reversal_operation: cancel_checkout
    window: >-
      Not stated. cancel_checkout is available before complete_checkout; no time limit is
      published.
    grade: documented
    source: https://shop.oatside.com/api/ucp/mcp
  - surface: order
    write_operations:
    - complete_checkout
    reversal_operation: none via API
    window: >-
      "returns and exchange requests have to be made within 7 days from the day the order
      is received" (merchandise). Food and beverage products are returnable or
      exchangeable only for damaged items or incorrect orders, reviewed case by case,
      with no time window stated.
    process: >-
      Out of band — email contact@oatside.com with the order number and photos. There is no
      refund, void or reverse tool in the MCP manifest, so an agent cannot undo a completed
      order programmatically.
    grade: verified
    source: https://shop.oatside.com/policies/refund-policy
  caveat: >-
    The 7-day window is a merchandise return policy, not an API-level reversal guarantee.
    An agent must treat complete_checkout as terminal and irreversible through the API.