# Arthur Online **Canonical:** https://apis.io/providers/arthur-online/ **Website:** https://www.arthuronline.co.uk/ **APIs profiled:** 16 Arthur Online is a London-headquartered UK property management software platform, founded in 2008 and acquired by Aareon in January 2021, that gives letting agents, self-managing landlords, block and social housing managers, and student accommodation operators a cloud system of record for properties, units, tenancies, tenants, applicants, viewings, maintenance work orders, certificates, utilities and rental financials, with companion mobile apps for managers, tenants, contractors and owners. It sits in the middle of the UK residential lettings value chain: it is the agency-side operational system that pushes stock out to the Rightmove and Zoopla portals and pulls accounting into Xero and QuickBooks, rather than a listings marketplace or a data cooperative. Its API posture is unusually open for the sector but is not open data: the full Arthur API v2 reference is published without a login as a public Postman collection at developer.arthuronline.co.uk covering 324 documented requests across 16 resource areas, yet every call is tenant-scoped OAuth 2.0 Authorization Code plus an X-EntityID header, credentials are issued only from inside a paying Arthur account after contacting Arthur support, and no data is readable anonymously. There is no RESO posture at all — the United Kingdom has no MLS, no NAR, and no RESO Data Dictionary or Web API certification regime, so listings interoperability here is portal-to-CRM feeds rather than a certified machine-readable standard. ## Kin Score — 52.1 / 100 (developing) Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 52.1). | Facet | Score | |---|---| | Discoverability | 81.5 | | Contract Quality | 26.2 | | Governance | 20.5 | | Contract Governance | 20.5 | | Operational Transparency | 31.6 | | Developer Ergonomics | 63.7 | | Commercial Clarity | 76.3 | | Access Clarity | 76.3 | Regulatory layer — **Education & Research**: 46.3 (matched via tags). ## Agent readiness — 44.7 (agent-ready) | Dimension | Value | |---|---| | Spec Presence | yes | | Agentic Access | derived | | Reversibility Documented | no | | MCP Server | no | | Auth Clarity | yes | | Idempotency | no | | Error Semantics | documented | | OpenAPI Examples | verified | | Rate Limit Signal | documented | | Event Surface Described | yes | | Agent Skills | derived | | Well Known Catalog | no | | Consent Identity | no | | Agent Card | no | | Dry Run Mode | no | ## APIs (16) - **Arthur Properties API** — Property records and everything hung off a property in Arthur - assets, certificates, conversations, general information, notes, units, tenancies, tasks, work orders, utilities,... - **Arthur Units API** — Individual lettable units beneath a property, plus the unit-level assets, certificates, conversations, notes, viewings, tenancies, tasks, work orders, utilities, transactions an... - **Arthur Tenancies API** — Tenancy agreements over a unit, including tenants on the tenancy, deposit registration, recurring charges, certificates, tasks, work orders, conversations, transactions, notes a... - **Arthur Tenants API** — Tenant people records - list, view, create and update tenants, and invite a tenant into the Arthur tenant portal. 3 documented paths. - **Arthur Applicants API** — Prospective renters moving through the lettings funnel, including applicant status, credit checks, managers, assets, conversations, notes, tasks and tags. 15 documented paths. - **Arthur Viewings API** — Property and unit viewing appointments, the applicants attached to each viewing, assigned managers, conversations, notes and tags. 15 documented paths. - **Arthur Maintenance API** — The largest surface in the API - tasks, subtasks, work orders, quotes and the contractor workflow around them. 45 documented paths. - **Arthur Financials API** — Rental financials - invoices, transactions, transaction payoff and recurring charges. Read and update only; no create operations are documented. 6 documented paths. - **Arthur Assets API** — Files and documents stored in Arthur and shared with owners, tenants and contractors. 2 documented paths. - **Arthur Utilities API** — Utility accounts attached to properties and units, and the meter readings recorded against them. 4 documented paths. - **Arthur Certificates API** — Compliance certificates - gas safety, electrical, EPC and similar - with expiry tracking that also drives webhook events at 30 days, 7 days and on the day. 2 documented paths. - **Arthur Entities API** — Arthur entities - the account boundary that every API call must name in the mandatory X-EntityID request header. 2 documented paths. - **Arthur Conversations API** — Threaded conversations and messages between managers, tenants, owners and contractors, with attached assets. 4 documented paths. - **Arthur Tags API** — Cross-cutting tags applied to properties, units, tenancies, applicants, viewings and notes, with tag and untag operations on each resource. 2 documented paths. - **Arthur Notes API** — Free-text notes recorded against any Arthur resource, with their own tagging operations. 5 documented paths. - **Arthur Types API** — Read-only reference vocabularies backing every enumerated field in Arthur - access detail types, applicant statuses and types, area types, asset types, certificate types, citize... ## MCP servers (1) - **Arthur Online MCP Server** — Arthur Online publishes no MCP server. This is a CANDIDATE tool surface derived one-for-one from the Arthur API v2 operations, so an agent builder can stand up a local MCP serve... ## Agentic access (1) - **Arthur Online Agentic Access** — 317 operations · 137 acting ## Security (2) - **Arthur Online Authentication** — oauth2 · 1 scheme - **Arthur Online Domain Security** — TLSv1.3 · HSTS · DMARC ## Plans (1) - **Arthur Online Plans** ## Tags Real-Estate, United Kingdom, Property Management, PropTech, Rentals, Lettings, Tenancy, Maintenance, Property Listings, Social Housing, Student Housing, Block Management --- Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/arthur-online/). Scores are computed from the provider's own public artifacts under a published rubric.