TwentyCi website screenshot

TwentyCi

TwentyCi is a United Kingdom residential property data and home-mover intelligence company. It aggregates roughly 31.5 million UK addresses and tens of billions of data points from hundreds of primary sources into the DOMUS property database, and sells that data to estate agents, lenders, insurers, conveyancers, house builders, retailers and media agencies through the TwentyCi, TwentyEA and TwentyConvey brands. In the UK value chain it sits on the data-supply side rather than the listing side - there is no UK MLS, listings are controlled by the Rightmove and Zoopla portals, and TwentyCi is one of the private aggregators that resells transaction, valuation and home-mover signal on top of that closed market. Its API posture is honest but commercial - TwentyAPI is a genuine RESTful v2 API at https://api.twentyci.co.uk/api/v2 with a live, publicly readable documentation portal covering roughly 57 documented operations across properties, AVM valuation, transaction triggers, agent performance, address matching, schools, housing market metrics and retail propensity - but every endpoint returns 401 without a TwentyCi-issued OAuth 2.0 bearer token, there is no self-serve signup, no published pricing, and the specification download TwentyCi advertises at https://api.twentyci.co.uk/docs/v2/spec.json returns HTTP 404. Access is sales-led and partner-only. RESO is entirely absent - the UK has no MLS or RESO regime and TwentyCi identifies property by UPRN, the Ordnance Survey/GeoPlace Unique Property Reference Number, rather than by any RESO Universal Property Identifier.

TwentyCi publishes 9 APIs on the APIs.io network, including Address Match API, Agent Performance API, Authorisation API, and 6 more. Tagged areas include Real-Estate, United Kingdom, PropTech, Property Data, and Valuation.

TwentyCi’s developer surface includes authentication, code examples, documentation, API reference, getting-started guide, engineering blog, and 29 more developer resources.

29.8/100 thin ▬ flat Agent 24/100 agent aware Full breakdown ↓
scored 2026-09-08 · rubric v0.20.0
AccessSelf serve
2 APIs
Real-EstateUnited KingdomPropTechProperty DataValuationAVMRentalsAddress DataConveyancingHomemover DataAgent PerformanceData as a Service

Kin Score

Kin Score Kin Score How this is scored →
scored 2026-09-08 · rubric v0.20.0
Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.
Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from github.com/api-evangelist/twentyci: open an issue to ask a question, or submit a pull request to add artifacts. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

APIs 9

Individual APIs this provider publishes, each with its own machine-readable definition.

TwentyCi Address Match API

- Partial Address Matching

TwentyCi Agent Performance API

- Agent Performance based on Sales Data - Agent Performance based on Rental Data

TwentyCi Authorisation API

Bearer-token issuance for TwentyAPI.

TwentyCi Categories API

- Obtain a List of Categories for a Property - Obtain a Specific Categories for a Property

TwentyCi Properties API

- Property Information by Pagination - Properties Information by UPRN - Properties Details by UPRN - Recent Property Sales in the Area - Similar properties for sale in the area ...

TwentyCi Schools API

- Nearby Schools by Postcode

TwentyCi Trigger Information API

- Obtain a Specific Trigger - Get Properties by Trigger Type - Get no UPRN Properties by Trigger Type - Trigger History

TwentyCi UK Housing Market Metrics API

- New Instructions, SSTC's and PCD's for a Specific Timeframe

Scroll for all 9

Open Collections 2

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

TwentyAPI (TwentyCi) v2

OPEN COLLECTION

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Twentyci Authentication

oauth2 · 1 scheme

SECURITY

Twentyci Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Scopes 1

OAuth scopes governing access to this provider's APIs.

Twentyci Scopes

1 scope · password

1 scopes

SCOPES

Agentic Access 1

Recommended x-agentic-access execution contracts for AI agents.

Twentyci Agentic Access

58 operations · 6 acting

58 operations · 6 acting

AGENTIC

Resources

Get Started 2

Portal, sign-up, and the first successful call

Documentation 2

Reference material describing how the API behaves

Agent Surfaces 4

MCP servers, agent skills, and machine-readable catalogs

Design & Contract 6

Pagination, idempotency, versioning, errors, and events

Build 3

SDKs, sample code, and the tooling you integrate with

Access & Security 4

Authentication, authorization, and security posture

Operate 1

Status, limits, changes, and where to get help

Commercial 1

Pricing, plans, and the legal terms of use

Company 8

The organization behind the API

Scroll for all 8

Other 4

Properties that don't map to a standard resource type

Source (apis.yml)

apis.yml Raw ↑
aid: twentyci
url: https://raw.githubusercontent.com/api-evangelist/twentyci/refs/heads/main/apis.yml
name: TwentyCi
kind: company
description: TwentyCi is a United Kingdom residential property data and home-mover intelligence company. It aggregates roughly
  31.5 million UK addresses and tens of billions of data points from hundreds of primary sources into the DOMUS property database,
  and sells that data to estate agents, lenders, insurers, conveyancers, house builders, retailers and media agencies through
  the TwentyCi, TwentyEA and TwentyConvey brands. In the UK value chain it sits on the data-supply side rather than the listing
  side - there is no UK MLS, listings are controlled by the Rightmove and Zoopla portals, and TwentyCi is one of the private
  aggregators that resells transaction, valuation and home-mover signal on top of that closed market. Its API posture is honest
  but commercial - TwentyAPI is a genuine RESTful v2 API at https://api.twentyci.co.uk/api/v2 with a live, publicly readable
  documentation portal covering roughly 57 documented operations across properties, AVM valuation, transaction triggers, agent
  performance, address matching, schools, housing market metrics and retail propensity - but every endpoint returns 401 without
  a TwentyCi-issued OAuth 2.0 bearer token, there is no self-serve signup, no published pricing, and the specification download
  TwentyCi advertises at https://api.twentyci.co.uk/docs/v2/spec.json returns HTTP 404. Access is sales-led and partner-only.
  RESO is entirely absent - the UK has no MLS or RESO regime and TwentyCi identifies property by UPRN, the Ordnance Survey/GeoPlace
  Unique Property Reference Number, rather than by any RESO Universal Property Identifier.
deliveryModel:
  model: unknown
  open_source: false
  commercial: false
  callable_host: true
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - openapi
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: self-serve
  trial: false
  try_now: false
  public: false
  label: Self-serve signup
  confidence: low
  source:
  - authentication
  - security
  generated: '2026-09-02'
  method: derived
image: https://www.twentyci.co.uk/favicon.ico
tags:
- Real-Estate
- United Kingdom
- PropTech
- Property Data
- Valuation
- AVM
- Rentals
- Address Data
- Conveyancing
- Homemover Data
- Agent Performance
- Data as a Service
tags_raw:
- Real Estate
- United Kingdom
- PropTech
- Property Data
- Valuation
- AVM
- Rentals
- Address Data
- Conveyancing
- Homemover Data
- Agent Performance
- Data as a Service
created: '2026-07-26'
modified: '2026-07-26'
specificationVersion: '0.23'
apis:
- aid: twentyci:twentyci-address-match-api
  name: TwentyCi Address Match API
  description: '- Partial Address Matching'
  humanURL: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  baseURL: https://api.twentyci.co.uk
  tags:
  - Address Match
  properties:
  - type: OpenAPI
    url: openapi/twentyci-address-match-api-openapi.yml
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#properties
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#agent-performance
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#trigger-information
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#categories
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#address-match
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#schools
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#uk-housing-market-metrics
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#this-is-now-retail-propensity-to-buy-goods
- aid: twentyci:twentyci-agent-performance-api
  name: TwentyCi Agent Performance API
  description: '- Agent Performance based on Sales Data - Agent Performance based on Rental Data'
  humanURL: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  baseURL: https://api.twentyci.co.uk
  tags:
  - Agent Performance
  properties:
  - type: OpenAPI
    url: openapi/twentyci-agent-performance-api-openapi.yml
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#properties
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#agent-performance
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#trigger-information
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#categories
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#address-match
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#schools
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#uk-housing-market-metrics
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#this-is-now-retail-propensity-to-buy-goods
- aid: twentyci:twentyci-authorisation-api
  name: TwentyCi Authorisation API
  description: Bearer-token issuance for TwentyAPI.
  humanURL: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  baseURL: https://api.twentyci.co.uk
  tags:
  - Authorisation
  properties:
  - type: OpenAPI
    url: openapi/twentyci-authorisation-api-openapi.yml
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#properties
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#agent-performance
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#trigger-information
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#categories
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#address-match
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#schools
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#uk-housing-market-metrics
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#this-is-now-retail-propensity-to-buy-goods
- aid: twentyci:twentyci-categories-api
  name: TwentyCi Categories API
  description: '- Obtain a List of Categories for a Property - Obtain a Specific Categories for a Property'
  humanURL: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  baseURL: https://api.twentyci.co.uk
  tags:
  - Categories
  properties:
  - type: OpenAPI
    url: openapi/twentyci-categories-api-openapi.yml
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#properties
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#agent-performance
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#trigger-information
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#categories
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#address-match
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#schools
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#uk-housing-market-metrics
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#this-is-now-retail-propensity-to-buy-goods
- aid: twentyci:twentyci-properties-api
  name: TwentyCi Properties API
  description: '- Property Information by Pagination - Properties Information by UPRN - Properties Details by UPRN - Recent
    Property Sales in the Area - Similar properties for sale in the area - Average Property Values by Postcode - Searching
    Properties by Postcode and Radius - Searching Properties by Postcode and Address - Property Attributes - Property Attributes
    for a Given Category - Obtaining a Google Map UR'
  humanURL: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  baseURL: https://api.twentyci.co.uk
  tags:
  - Properties
  properties:
  - type: OpenAPI
    url: openapi/twentyci-properties-api-openapi.yml
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#properties
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#agent-performance
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#trigger-information
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#categories
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#address-match
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#schools
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#uk-housing-market-metrics
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#this-is-now-retail-propensity-to-buy-goods
- aid: twentyci:twentyci-schools-api
  name: TwentyCi Schools API
  description: '- Nearby Schools by Postcode'
  humanURL: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  baseURL: https://api.twentyci.co.uk
  tags:
  - Schools
  properties:
  - type: OpenAPI
    url: openapi/twentyci-schools-api-openapi.yml
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#properties
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#agent-performance
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#trigger-information
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#categories
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#address-match
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#schools
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#uk-housing-market-metrics
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#this-is-now-retail-propensity-to-buy-goods
- aid: twentyci:twentyci-this-is-now-retail-propensity-to-buy-goods-api
  name: TwentyCi This is Now | Retail Propensity To Buy Goods API
  description: '- Local Search - National Search'
  humanURL: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  baseURL: https://api.twentyci.co.uk
  tags: []
  tags_raw:
  - This is Now | Retail Propensity To Buy Goods
  properties:
  - type: OpenAPI
    url: openapi/twentyci-this-is-now-retail-propensity-to-buy-goods-api-openapi.yml
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#properties
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#agent-performance
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#trigger-information
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#categories
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#address-match
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#schools
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#uk-housing-market-metrics
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#this-is-now-retail-propensity-to-buy-goods
- aid: twentyci:twentyci-trigger-information-api
  name: TwentyCi Trigger Information API
  description: '- Obtain a Specific Trigger - Get Properties by Trigger Type - Get no UPRN Properties by Trigger Type - Trigger
    History'
  humanURL: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  baseURL: https://api.twentyci.co.uk
  tags:
  - Trigger Information
  properties:
  - type: OpenAPI
    url: openapi/twentyci-trigger-information-api-openapi.yml
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#properties
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#agent-performance
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#trigger-information
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#categories
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#address-match
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#schools
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#uk-housing-market-metrics
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#this-is-now-retail-propensity-to-buy-goods
- aid: twentyci:twentyci-uk-housing-market-metrics-api
  name: TwentyCi UK Housing Market Metrics API
  description: '- New Instructions, SSTC''s and PCD''s for a Specific Timeframe'
  humanURL: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  baseURL: https://api.twentyci.co.uk
  tags:
  - UK Housing Market Metrics
  properties:
  - type: OpenAPI
    url: openapi/twentyci-uk-housing-market-metrics-api-openapi.yml
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#authorisation-for-api-requests
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#properties
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#agent-performance
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#trigger-information
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#categories
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#address-match
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#schools
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#uk-housing-market-metrics
  - type: Documentation
    url: https://api.twentyci.co.uk/documentation#this-is-now-retail-propensity-to-buy-goods
common:
- type: AgenticAccess
  url: agentic-access/twentyci-agentic-access.yml
- type: DomainSecurity
  url: security/twentyci-domain-security.yml
- type: OAuthScopes
  url: scopes/twentyci-scopes.yml
- type: Authentication
  url: authentication/twentyci-authentication.yml
- type: Vocabulary
  url: vocabulary/twentyci-vocabulary.yml
- type: Conventions
  url: conventions/twentyci-conventions.yml
- type: ErrorCatalog
  url: errors/twentyci-problem-types.yml
- type: Examples
  url: examples/twentyci-examples.yml
- type: DataModel
  url: data-model/twentyci-data-model.yml
- type: Lifecycle
  url: lifecycle/twentyci-lifecycle.yml
- type: Conformance
  url: conformance/twentyci-conformance.yml
- type: Compliance
  url: https://www.twentyci.co.uk/privacy-policy/
- type: Packages
  url: packages/twentyci-packages.yml
- type: X-MCPServerCandidate
  url: mcp/twentyci-mcp.yml
  note: 'Renamed from MCPServer 2026-09-03 (roadmap#247): the manifest self-describes as status: candidate — a tool list derived
    from the published API contracts, not an existing server. The scorer already read the manifest and reported mcp_server
    correctly; the MCPServer type was crediting the artifact-type surfaces with a server that does not exist.'
- type: AgentSkill
  url: skills/_index.yml
- type: LLMsTxt
  url: llms/twentyci-llms.txt
- type: Overlay
  name: TwentyAPI v2 enhancements
  url: overlays/twentyci-twentyapi-overlay.yaml
- type: Overlay
  name: TwentyAPI OAuth token enhancements
  url: overlays/twentyci-twentyapi-oauth-overlay.yaml
- type: Website
  url: https://www.twentyci.co.uk/
- type: DeveloperPortal
  url: https://api.twentyci.co.uk/documentation
- type: Documentation
  url: https://api.twentyci.co.uk/documentation
- type: APIReference
  url: https://api.twentyci.co.uk/documentation#properties
- type: GettingStarted
  url: https://api.twentyci.co.uk/documentation#overview
- type: Contact
  url: https://www.twentyci.co.uk/contact/
- type: About
  url: https://www.twentyci.co.uk/about-us/
- type: Blog
  url: https://news.twentyci.co.uk/blog
- type: BlogRSS
  url: https://www.twentyci.co.uk/feed/
- type: PrivacyPolicy
  url: https://www.twentyci.co.uk/privacy-policy/
- type: CookiePolicy
  url: https://www.twentyci.co.uk/cookies-policy/
- type: SustainabilityPolicy
  url: https://www.twentyci.co.uk/sustainability-policy/
- type: Careers
  url: https://www.twentyci.co.uk/careers/
- type: LinkedIn
  url: https://www.linkedin.com/company/twentyci/
- type: Twitter
  url: https://twitter.com/TwentyCi
- type: Facebook
  url: https://www.facebook.com/TwentyCi
- type: GitHubOrganization
  url: https://github.com/twentyci
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com

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