generated: '2026-08-04'
method: searched
source: https://partyshop.paperlesspost.com/agents.md
scope: >-
  Cross-cutting request/response semantics for the only machine-callable
  Paperless Post surface, the Party Shop storefront
  (partyshop.paperlesspost.com). www.paperlesspost.com has no public API and
  therefore no published conventions.
authentication:
  style: OAuth 2.0 authorization code + PKCE (S256) via OIDC; bearer token in the
    Authorization header
  anonymous: Read-only product/collection JSON requires no authentication
  see: authentication/paperless-post-authentication.yml
idempotency:
  supported: false
  note: >-
    No idempotency key header, parameter, or retry contract is documented on any
    Paperless Post surface. Deliberately NOT wired as a type Idempotency pointer.
pagination:
  style: page + limit query parameters on the storefront JSON endpoints
  params: [limit, page]
  example: /collections/all/products.json?limit=2
  note: Shopify storefront JSON convention; not documented by Paperless Post itself.
versioning:
  style: date-versioned protocol negotiation (UCP)
  current: '2026-04-08'
  see: lifecycle/paperless-post-lifecycle.yml
error_envelope:
  style: JSON-RPC 2.0 error object on the MCP endpoint
  shape: '{"jsonrpc":"2.0","id":<id>,"error":{"code":<int>,"message":<string>,"data":{"code":<slug>,"content":<string>,"continue_url":<url>}}}'
  observed:
  - {code: -32001, message: UCP discovery failed, data_code: invalid_profile_url}
  problem_json: false
rate_limits:
  documented: true
  quantified: false
  signal: 'HTTP 429'
  guidance: The MCP endpoint is rate-limited per IP; agents must back off on 429 responses.
  note: No numeric limit, window, or RateLimit-* header contract is published.
agent_context:
  required_context_fields:
  - context.address_country
  - context.currency
  human_in_the_loop: >-
    Checkout completion requires contemporaneous buyer approval; agents must not
    complete payment without explicit consent.
  recommended_client_skill: https://shop.app/SKILL.md
request_tracing:
  request_id_header: null
metadata:
  supported: false
field_expansion:
  supported: false
x-evidence:
  fetched: '2026-08-04'
  urls:
  - {url: 'https://partyshop.paperlesspost.com/agents.md', http_status: 200}
  - {url: 'https://partyshop.paperlesspost.com/llms.txt', http_status: 200}
  - {url: 'https://partyshop.paperlesspost.com/api/ucp/mcp', http_status: 422, method: POST}
  - {url: 'https://partyshop.paperlesspost.com/collections/all/products.json?limit=2',
    http_status: 200}