TwentyCi Categories API

openapi: 3.2.0
info:
  title: TwentyAPI (TwentyCi) v2 Categories API
  version: v2
  summary: UK residential property, valuation (AVM), transaction-trigger and agent-performance data from TwentyCi.
  description: 'TwentyAPI is TwentyCi''s RESTful data-as-a-service API over the DOMUS UK residential property database. Properties are addressed by UPRN (Unique Property Reference Number), the UK national property identifier, rather than by any MLS or RESO identifier. Access is credentialed: an OAuth 2.0 password-grant token is minted at POST https://api.twentyci.co.uk/oauth/token using a client_id, client_secret, username and password issued by TwentyCi under a commercial data agreement. There is no self-serve developer signup.


    PROVENANCE: This document was harvested by API Evangelist on 2026-07-26 from TwentyCi''s own published documentation corpus at https://api.twentyci.co.uk/api/documentation/markdocs (HTTP 200, application/json, 247,074 bytes), which is served publicly without authentication and backs the TwentyAPI documentation SPA at https://api.twentyci.co.uk/documentation. Every path, method, parameter name, parameter type and required flag below is transcribed from that corpus''s own "{% route %}" and "{% param %}" declarations. Response schemas beyond HTTP status codes are NOT modelled, because TwentyCi does not publish them in machine-readable form. TwentyCi advertises a downloadable specification at https://api.twentyci.co.uk/docs/v2/spec.json, but that URL returned HTTP 404 on 2026-07-26; this document is an API Evangelist derivation, not a provider-published artifact.'
  contact:
    name: TwentyCi
    url: https://www.twentyci.co.uk/contact-us/
servers:
- url: https://api.twentyci.co.uk/api/v2
  description: TwentyAPI v2 root URL, as published in the TwentyAPI Overview.
security:
- twentyapiOAuth: []
tags:
- name: Categories
  description: '- Obtain a List of Categories for a Property - Obtain a Specific Categories for a Property'
paths:
  /categories:
    get:
      operationId: obtain_a_list_of_categories_for_a_property
      summary: Obtain a List of Categories for a Property
      tags:
      - Categories
      externalDocs:
        description: TwentyAPI documentation
        url: https://api.twentyci.co.uk/documentation#obtain-a-list-of-categories-for-a-property
      responses:
        '200':
          description: Successful response.
          content:
            application/json:
              schema:
                type: object
        '401':
          description: Unauthorized - authentication credentials were missing or incorrect.
        '404':
          description: Not Found - the URI requested is invalid or the resource does not exist.
        '422':
          description: Unprocessable Entity - request is invalid or unable to be validated.
      x-documented-route: /categories
      description: The /categories endpoint in TwentyAPI allows developers to retrieve essential property category data, emphasizing efficient organisation and seamless API integration. This endpoint's output, including Category ID and Category information, proves invaluable for streamlined communication and improved development processes.
      parameters:
      - name: page
        in: query
        required: false
        description: The page number of the paginated result set you wish to retrieve
        schema:
          type: integer
  /categories/{category}:
    get:
      operationId: obtain_a_specific_category_for_a_property
      summary: Obtain a Specific Category for a Property
      tags:
      - Categories
      externalDocs:
        description: TwentyAPI documentation
        url: https://api.twentyci.co.uk/documentation#obtain-a-specific-category-for-a-property
      responses:
        '200':
          description: Successful response.
          content:
            application/json:
              schema:
                type: object
        '401':
          description: Unauthorized - authentication credentials were missing or incorrect.
        '404':
          description: Not Found - the URI requested is invalid or the resource does not exist.
        '422':
          description: Unprocessable Entity - request is invalid or unable to be validated.
      x-documented-route: /categories/{category}
      description: The /categories/{category} in TwentyAPI is designed to return a specific category and its relevant data using information from the output of /categories. This targeted data retrieval enhances efficiency, optimizes performance, and supports modular development.
      parameters:
      - name: id
        in: query
        required: true
        description: ID of category to fetch
        schema:
          type: integer
      - name: category
        in: path
        required: true
        schema:
          type: string
        description: Path parameter as documented by TwentyCi.
components:
  securitySchemes:
    twentyapiOAuth:
      type: oauth2
      description: 'OAuth 2.0 bearer token. TwentyCi''s documentation labels the scheme "OAuth2" with flow "Implicit" but describes a resource-owner password-credentials exchange: POST /oauth/token with client_id, client_secret, username, password, grant_type=password and scope=* returns {token_type: Bearer, expires_in, access_token, refresh_token}. The token is then sent as "Authorization: Bearer <token-key>". Modelled here as the password flow because that is what the documented request body performs. No OpenID Connect discovery document is served (/.well-known/openid-configuration returned 404).'
      flows:
        password:
          tokenUrl: https://api.twentyci.co.uk/oauth/token
          refreshUrl: https://api.twentyci.co.uk/oauth/token
          scopes:
            '*': Full access; the only scope value documented by TwentyCi.
externalDocs:
  description: TwentyAPI documentation
  url: https://api.twentyci.co.uk/documentation
x-provenance:
  harvestedBy: API Evangelist
  harvestDate: '2026-07-26'
  derived: true
  providerPublished: false
  sources:
  - url: https://api.twentyci.co.uk/api/documentation/markdocs
    status: 200
    contentType: application/json
    bytes: 247074
    note: Public, unauthenticated JSON documentation corpus (66 nodes) backing the TwentyAPI docs SPA.
  - url: https://api.twentyci.co.uk/documentation
    status: 200
    contentType: text/html
    note: React/Markdoc single-page app shell; renders the corpus above.
  - url: https://api.twentyci.co.uk/docs/v2/spec.json
    status: 404
    note: Specification download advertised in the TwentyAPI Overview page. NOT served.
  anomalies:
  - TwentyCi advertises https://api.twentyci.co.uk/docs/v2/spec.json as a downloadable specification; it returned HTTP 404 on 2026-07-26. No provider-published OpenAPI exists.
  - Several documented route strings are irregular (e.g. "api/v2/propertiesavm2/{property}", "api/v2/{uprn}/likely-to-sell"). They are transcribed verbatim and flagged with x-documented-route-note rather than corrected.
  - The documentation page "Obtain a Specific Trigger" declares the route "/categories", which is inconsistent with its own section index route "/trigger/{trigger}".
  - Several routes are listed only on a section index page with no parameter documentation; they are included with no asserted parameters.
  - TwentyCi labels the security scheme OAuth2 with the "Implicit" flow while documenting a resource-owner password-credentials request body. Modelled as the password flow.