generated: '2026-07-26'
method: derived
source: openapi/apex27-crm-api-openapi.yml, openapi/apex27-portal-api-openapi.yml, npm n8n-nodes-apex27crm@1.0.4,
  live probes
authentication:
  crm_api:
    style: api key in request header
    header: x-api-key
    issuance: CRM admin panel, paying tenants only
    self_serve: false
  portal_api:
    style: api key in query string
    parameter: api_key
    issuance: Admin Panel > Websites > [Your Website] > Integrations tab > Portal API section
    self_serve: false
  see: authentication/apex27-authentication.yml
idempotency:
  supported: false
  header: null
  evidence: No idempotency key header, parameter or documented retry semantics appears in Apex27's own
    client node or anywhere on the public site. Creates (POST /contacts, POST /leads, POST /listings/{listingId}/viewings)
    are not safely retryable. No Idempotency pointer is wired because there is no idempotency contract.
pagination:
  style: page number
  params:
  - page
  - pageSize
  page_minimum: 1
  page_size_default: 25
  page_size_minimum: 25
  page_size_maximum: 250
  applies_to: Apex27 CRM API list operations
  portal_api:
    params:
    - page
    - page_size
    style: page number
  response_fields: null
  response_fields_evidence: No response envelope is published, so the pagination metadata fields returned
    by the API are unknown.
filtering:
  style: flat query parameters
  examples:
  - minDtsUpdated
  - minDtsCreatedUpdated
  - includeArchived
  - branchId
  - transactionType
  incremental_sync:
    supported: true
    params:
    - minDtsUpdated
    - minDtsCreatedUpdated
    note: Contacts, listings, tenancies and listing searches accept a minimum-updated timestamp, which
      makes incremental polling possible in the absence of an event catalogue.
field_expansion:
  style: boolean include flags
  params:
  - includeContacts
  - includeImages
  - includeOffers
  - includeValuations
  - includeRooms
  applies_to: GET /listings and GET /listings/{listingId}
partial_update:
  supported: true
  methods:
  - PATCH
  note: Contacts, listings and tenancies support PATCH alongside a full-replace PUT. Most other resources
    are PUT-only.
custom_headers:
  supported: true
  note: Apex27's own node exposes an arbitrary custom-header collection on every request, implying the
    API tolerates additional headers.
request_tracing:
  header: null
  evidence: No request-id or correlation header is documented or returned in the probed 401 responses.
versioning:
  style: none
  see: lifecycle/apex27-lifecycle.yml
error_envelope:
  shape:
    success: boolean
    message: string
    errors: array
  media_type: text/json
  rfc9457: false
  example:
    success: false
    message: Unauthorised.
    errors: []
  evidence: Recorded verbatim from a live probe of https://api.apex27.co.uk/ on 2026-07-26.
  see: errors/apex27-problem-types.yml
rate_limiting:
  documented: false
  headers: null
  evidence: No rate-limit documentation and no RateLimit/X-RateLimit headers observed on the anonymous
    401 responses.
content_types:
  request:
  - application/json (CRM API)
  - application/x-www-form-urlencoded (Portal API writes)
  response:
  - text/json