openapi: 3.2.0
info:
  title: Apex27 CRM Viewings API
  version: 1.0.4
  summary: REST interface over the Apex27 estate agency CRM (UK sales, lettings and commercial).
  description: 'API Evangelist DERIVED description of the Apex27 CRM API.


    Apex27 publishes no OpenAPI, Swagger, Postman collection or reference documentation. The documentation URL declared inside Apex27''s own npm credential (https://docs.apex27.co.uk) returned HTTP 404 on 2026-07-26. This document was derived mechanically from Apex27''s OWN published n8n community node — npm n8n-nodes-apex27crm@1.0.4, publisher "james_apex27" — which contains the complete request map (paths, HTTP methods, path parameters, query filters, auth header, both environment base URLs and the pagination bounds).


    It is NOT a provider-published contract. Response schemas are intentionally left open (`type: object`) because no response shape is published anywhere; only the 401 envelope is recorded verbatim from a live probe of https://api.apex27.co.uk. Authentication is an `x-api-key` request header issued to paying customers inside the CRM admin panel — there is no self-serve developer signup and no sandbox.'
  contact:
    name: Apex27
    url: https://apex27.co.uk/contact-apex27
  x-apievangelist-provenance:
    method: derived
    generated: '2026-07-26'
    provider_published: false
    source: https://www.npmjs.com/package/n8n-nodes-apex27crm (v1.0.4, dist/nodes/Apex27Crm/Apex27Crm.node.js)
    source_publisher: james_apex27 (Apex27)
    evidence:
    - kind: npm-package
      url: https://registry.npmjs.org/n8n-nodes-apex27crm
      note: v1.0.4 — dist/nodes/Apex27Crm/Apex27Crm.node.js holds every method+URL pair reproduced here.
    - kind: live-probe
      url: https://api.apex27.co.uk/
      status: 401
      note: Body {"success":false,"message":"Unauthorised.","errors":[]} — the 401 envelope recorded in components.schemas.Error.
    - kind: live-probe
      url: https://api.apex27.co.uk/branches
      status: 401
    - kind: live-probe
      url: https://api.apex27.co.uk/listings
      status: 401
    - kind: live-probe
      url: https://api.apex27.co.uk/webhooks
      status: 401
    - kind: live-probe
      url: https://api.apex27.co.uk/properties
      status: 404
      note: Confirms the 401s are real routes rather than a blanket auth wall.
    - kind: dead-link
      url: https://docs.apex27.co.uk
      status: 404
      note: documentationUrl declared inside Apex27CrmApi.credentials.js.
servers:
- url: https://api.apex27.co.uk
  description: Production
- url: https://dev-api.apex27.co.uk
  description: Development (key-gated, not an open sandbox)
security:
- ApiKeyAuth: []
tags:
- name: Viewings
  description: Viewing appointments.
paths:
  /viewings:
    get:
      operationId: listViewings
      summary: Get all viewings
      description: Get all viewings. Derived from the request the Apex27-published n8n node issues for this resource and operation.
      tags:
      - Viewings
      parameters:
      - name: page
        in: query
        required: false
        description: Page number (minimum 1).
        schema:
          type: integer
          minimum: 1
          default: 1
      - name: pageSize
        in: query
        required: false
        description: Records per page (minimum 25, maximum 250).
        schema:
          type: integer
          minimum: 25
          maximum: 250
          default: 25
      responses:
        '200':
          description: Successful response.
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorised'
        '404':
          $ref: '#/components/responses/NotFound'
  /listings/{listingId}/viewings:
    get:
      operationId: listListingViewings
      summary: Get viewings for a listing
      description: Get viewings for a listing. Derived from the request the Apex27-published n8n node issues for this resource and operation.
      tags:
      - Viewings
      parameters:
      - name: listingId
        in: path
        required: true
        schema:
          type: integer
        description: Apex27 listing identifier.
      - name: page
        in: query
        required: false
        description: Page number (minimum 1).
        schema:
          type: integer
          minimum: 1
          default: 1
      - name: pageSize
        in: query
        required: false
        description: Records per page (minimum 25, maximum 250).
        schema:
          type: integer
          minimum: 25
          maximum: 250
          default: 25
      responses:
        '200':
          description: Successful response.
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorised'
        '404':
          $ref: '#/components/responses/NotFound'
    post:
      operationId: createListingViewing
      summary: Create a viewing on a listing
      description: Create a viewing on a listing. Derived from the request the Apex27-published n8n node issues for this resource and operation.
      tags:
      - Viewings
      parameters:
      - name: listingId
        in: path
        required: true
        schema:
          type: integer
        description: Apex27 listing identifier.
      requestBody:
        required: true
        description: Request body. The Apex27 CRM API accepts a JSON object; the vendor node passes the object through unmodified.
        content:
          application/json:
            schema:
              type: object
              additionalProperties: true
      responses:
        '200':
          description: Successful response.
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorised'
        '404':
          $ref: '#/components/responses/NotFound'
  /listings/{listingId}/viewings/{viewingId}:
    get:
      operationId: getListingViewing
      summary: Get a viewing
      description: Get a viewing. Derived from the request the Apex27-published n8n node issues for this resource and operation.
      tags:
      - Viewings
      parameters:
      - name: listingId
        in: path
        required: true
        schema:
          type: integer
        description: Apex27 listing identifier.
      - name: viewingId
        in: path
        required: true
        schema:
          type: integer
      responses:
        '200':
          description: Successful response.
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorised'
        '404':
          $ref: '#/components/responses/NotFound'
    put:
      operationId: updateListingViewing
      summary: Update a viewing
      description: Update a viewing. Derived from the request the Apex27-published n8n node issues for this resource and operation.
      tags:
      - Viewings
      parameters:
      - name: listingId
        in: path
        required: true
        schema:
          type: integer
        description: Apex27 listing identifier.
      - name: viewingId
        in: path
        required: true
        schema:
          type: integer
      requestBody:
        required: true
        description: Request body. The Apex27 CRM API accepts a JSON object; the vendor node passes the object through unmodified.
        content:
          application/json:
            schema:
              type: object
              additionalProperties: true
      responses:
        '200':
          description: Successful response.
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorised'
        '404':
          $ref: '#/components/responses/NotFound'
    delete:
      operationId: deleteListingViewing
      summary: Delete a viewing
      description: Delete a viewing. Derived from the request the Apex27-published n8n node issues for this resource and operation.
      tags:
      - Viewings
      parameters:
      - name: listingId
        in: path
        required: true
        schema:
          type: integer
        description: Apex27 listing identifier.
      - name: viewingId
        in: path
        required: true
        schema:
          type: integer
      responses:
        '200':
          description: Successful response.
          content:
            application/json:
              schema:
                type: object
                additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorised'
        '404':
          $ref: '#/components/responses/NotFound'
components:
  schemas:
    Error:
      type: object
      description: Apex27 CRM API error envelope, recorded verbatim from a live 401 response.
      properties:
        success:
          type: boolean
        message:
          type: string
        errors:
          type: array
          items:
            type: object
            additionalProperties: true
      required:
      - success
      - message
      examples:
      - success: false
        message: Unauthorised.
        errors: []
  responses:
    NotFound:
      description: The requested resource or route does not exist.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    Unauthorised:
      description: Unauthorised. The `x-api-key` header is missing, malformed or not valid for this tenant.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
          example:
            success: false
            message: Unauthorised.
            errors: []
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: x-api-key
      description: API key issued to a paying Apex27 tenant from the CRM admin panel. No self-serve issuance.