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.
Limited machine-readable signal and partial portal coverage — documentation a human can read, but little a machine or agent can consume without scraping.
API Evangelist profiles TwentyCi the way a machine reads it — 14 machine-readable artifacts across 9 APIs, pulled from the provider's own public surface and indexed so a developer, an analyst, or an AI agent can evaluate it against every other provider on the network.
Every provider in the network is reduced to the same set of machine-readable artifacts — OpenAPI contracts, event specifications, GraphQL schemas, runnable collections, pricing and rate-limit signals, security posture, OAuth scopes, and the agent surfaces (MCP servers and skills) that let software drive the API on its own. We profile them because the interface is the part of a company you can actually inspect: it is a truer signal of what a provider does than any marketing page. From those artifacts we compute the Kin Score — TwentyCi scores 38.0/100 (thin), with a separate agent-readiness read of 72/100 (agent native). The full breakdown is below, followed by every artifact we hold — each card links through to its machine-readable definition on apis.io.
Kin Score
This is the API Evangelist rating — a single, repeatable read computed from the artifacts on this page. Green fill is points earned; the red track is points possible, so every bar shows earned-versus-possible at a glance.
Kin Score
How this is scored →scored 2026-07-27 · rubric v0.5
How we profile TwentyCi
Each block below is one kind of artifact we hold for TwentyCi. For each we say what it is and why it earns a place in the profile, then list every one we've indexed — capped at two rows, scroll within the panel for the rest.
APIs 9
Each API is captured as its own OpenAPI definition — every operation, parameter, and response. This is the single most useful machine-readable description of what an API does, and it's what lets us score, lint, mock, and generate against it without asking the provider for anything.
Individual APIs this provider publishes, each with its own machine-readable definition.
TwentyAPI OAuth Token API
The single documented authentication endpoint for TwentyAPI. Exchanges a TwentyCi-issued client_id, client_secret, username and password for a bearer access token and refresh to...
TwentyAPI Properties API
The core DOMUS property surface of TwentyAPI. Retrieves property information and detail by UPRN, recent sales and comparable properties for sale in the area, average property va...
TwentyAPI Agent Performance API
Estate-agent and letting-agent benchmarking built on TwentyCi sales and rental data. Ranks brands by SSTC, new instructions, exchange, PIPA (percentage of initial price achieved...
TwentyAPI Trigger Information API
Home-mover event triggers - the transaction-lifecycle signals TwentyCi is built on. Retrieves a specific trigger, lists properties by trigger type (including properties with no ...
TwentyAPI Categories API
Lists the attribute categories available for a property and returns a specific category, providing the vocabulary that the Properties API's attribute endpoints are organised aro...
TwentyAPI Address Match API
Partial address matching. Submits a fragmentary or unstructured UK address to a match-address process and resolves it against TwentyCi's addressing layer, the capability markete...
TwentyAPI Schools API
Returns nearby schools for a given UK postcode, one of the neighbourhood-context datasets TwentyCi layers onto a property record.
TwentyAPI UK Housing Market Metrics API
Aggregate UK housing market metrics for a specified timeframe - new instructions, SSTCs (sold subject to contract) and PCDs (predicted to complete date) - the market-level view ...
TwentyAPI This is Now API
"This is Now" retail propensity to buy goods. Local and national search endpoints returning consumer propensity signal derived from home-mover events, aimed at retailers and med...
Scroll within the panel for all 9 ·
MCP Servers 1
Model Context Protocol servers expose these APIs directly to AI agents. We profile them because agent-native access is the fastest-growing way this provider's capabilities actually get used.
Model Context Protocol servers that expose these APIs to AI agents.
twentyci-mcp.yml
MCP SERVERSecurity Posture 2
Authentication, domain security, vulnerability disclosure, and trust-center signals — the evidence that a provider takes security seriously enough to document it. We profile it because you can't govern what you can't see.
Authentication, domain security, vulnerability disclosure, and trust-center signals.
Scopes 1
OAuth scopes are the vocabulary of least-privilege access. Profiling them shows exactly what an integration — or an agent acting on a user's behalf — is allowed to do.
OAuth scopes governing access to this provider's APIs.
Agentic Access 1
An x-agentic-access contract marks which operations are safe for an agent to run on its own and which need a human in the loop. It is the difference between an API an agent can use and one it can use safely.
Recommended x-agentic-access execution contracts for AI agents.
Resources
Every other property we hold for TwentyCi — documentation, portals, status pages, policies, and corporate surface — grouped by the job it does, following the integrator's arc from getting started to running in production.
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 within the panel for all 8 ·
Other 4
Properties that don't map to a standard resource type
← All providers · Data indexed from github.com/api-evangelist/twentyci · machine-readable index on apis.io