generated: '2026-08-01'
method: derived
source: openapi/engrail-therapeutics-content-openapi.yml
observed_from: https://www.engrail.com/wp-json/wp/v2/posts
note: >-
  Engrail publishes no API documentation of any kind. Every convention below was observed directly
  against the live host on 2026-08-01 or read out of the provider's own route-discovery document —
  nothing is assumed from the WordPress project's general documentation.
authentication:
  style: none-for-read
  detail: >-
    Public content collections are anonymously readable. Writes and non-public collections use HTTP
    Basic with a WordPress Application Password; the MCP surface uses OAuth 2.1 bearer tokens.
  see: authentication/engrail-therapeutics-authentication.yml
idempotency:
  supported: false
  detail: >-
    No idempotency key header, parameter, or retry contract is advertised anywhere on the surface.
    The public operations are all safe GETs, so idempotency is a property of HTTP method only.
  header: null
pagination:
  style: page-number
  request_params:
  - name: page
    default: 1
    minimum: 1
  - name: per_page
    default: 10
    minimum: 1
    maximum: 100
  - name: offset
    note: Accepted on collection endpoints as an alternative cursor into the result set.
  response_headers:
  - name: X-WP-Total
    description: Total number of items in the collection.
  - name: X-WP-TotalPages
    description: Total number of pages at the current per_page.
  - name: Link
    description: RFC 8288 link header carrying rel="next" and rel="prev".
  observed_example: 'GET /wp-json/wp/v2/posts?per_page=1 -> X-WP-Total: 10, X-WP-TotalPages: 10, Link rel="next"'
filtering_and_sorting:
  search_param: search
  ordering_params:
  - orderby
  - order
  include_exclude:
  - include
  - exclude
  slug_lookup: slug
  date_windows:
  - after
  - before
  - modified_after
  - modified_before
field_selection:
  sparse_fields:
    supported: true
    param: _fields
    detail: Comma-separated whitelist of response properties.
  expansion:
    supported: true
    param: _embed
    detail: Inlines linked resources (author, featured media, terms) under _embedded.
  context:
    param: context
    values: [view, embed, edit]
    default: view
    detail: Controls which field set is returned; `edit` requires authentication.
metadata:
  supported: partial
  detail: Registered post meta is exposed on a `meta` object where the site opts fields in.
request_tracing:
  request_id_header: null
  detail: No correlation or request-id header is returned.
versioning:
  scheme: uri-path
  current: wp/v2
  detail: >-
    Version is the REST namespace segment. Namespaces present on this host: wp/v2, oembed/1.0,
    wp-site-health/v1, wp-block-editor/v1, wp-abilities/v1, mcp, plus vendor plugin namespaces
    (yoast/v1, elementor/v1, elementor-pro/v1, cookieyes/v1, cky/v1, wpe/cache-plugin/v1,
    wpe_sign_on_plugin/v1, spoter-elementor/v2).
  see: lifecycle/engrail-therapeutics-lifecycle.yml
error_envelope:
  format: wordpress-rest
  rfc9457: false
  content_type: application/json
  shape:
    code: Machine-readable string code, e.g. rest_post_invalid_id.
    message: Human-readable message.
    data.status: HTTP status, repeated inside the body.
    data.params: Per-parameter validation messages (validation errors only).
    data.details: Per-parameter structured detail with its own nested code/message.
  see: errors/engrail-therapeutics-problem-types.yml
rate_limiting:
  signalled: false
  detail: >-
    No X-RateLimit-*, RateLimit-*, or Retry-After headers were returned on any probed response, and
    the provider publishes no rate-limit policy. Absence of signalling is not evidence of absence of
    limits — an nginx or WP Engine edge limit may apply unannounced.
caching:
  headers_observed:
  - x-robots-tag: noindex
  - strict-transport-security: max-age=63072000
  detail: Responses carry no explicit Cache-Control or ETag on the probed collection endpoints.
transport:
  https_only: true
  tls_version: TLSv1.3
  hsts: true
  hsts_max_age: 63072000
  see: security/engrail-therapeutics-domain-security.yml
x-evidence:
  fetched: '2026-08-01'
  probes:
  - url: https://www.engrail.com/wp-json/wp/v2/posts?per_page=1
    http_status: 200
    note: Pagination headers and Link rel=next observed here.
  - url: https://www.engrail.com/wp-json/wp/v2/posts?per_page=999
    http_status: 400
    note: rest_invalid_param with data.params and data.details.
  - url: https://www.engrail.com/wp-json/wp/v2/posts/999999999
    http_status: 404
    note: rest_post_invalid_id.