CoStar Group
CoStar Group is the dominant commercial and residential real estate data, analytics, and marketplace company. The portfolio spans the flagship CoStar commercial real estate intelligence platform, LoopNet (CRE marketplace), Apartments.com network (residential rentals, including ForRent.com and Westside Rentals), Homes.com and Homesnap (for-sale residential), Ten-X (online CRE auctions), BizBuySell (business-for-sale marketplace), STR (hotel data), Visual Lease (lease management), Matterport (3D spatial capture), and international properties including OnTheMarket (UK), Emporis (Germany), and a controlling stake in Domain Group (Australia). Distribution to partners is via enterprise data licensing, syndication feeds, and brand-specific marketplace tooling rather than a public self-serve developer portal.
More than an index entry, but the surface is still mostly links rather than artifacts — the cohort most likely to move a full band from modest, well-targeted work.
API Evangelist profiles CoStar Group the way a machine reads it — 19 machine-readable artifacts across 14 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 — CoStar Group scores 19.4/100 (emerging), with a separate agent-readiness read of 3/100 (human only). 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. Every facet and dimension name is a link: it opens that measurement's page on APIs.io, where the rating runs across the whole catalog — the exact checks that feed it, how every profiled provider distributes on it, and who is at the top of it.
Kin Score
How this is scored →scored 2026-09-08 · rubric v0.20.0
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title="CoStar Group on API Evangelist — API profile and Kin Score">
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alt="CoStar Group Kin Score — API readiness rating by API Evangelist" width="340" height="120" loading="lazy">
</a>More shapes, themes and sizes → · Score as JSON · How badges work
How we profile CoStar Group
Each block below is one kind of artifact we hold for CoStar Group. 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 14
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.
CoStar Commercial Real Estate Platform
CoStar's flagship commercial real estate information platform covering property, tenant, lease, sale, and market analytics across office, industrial, retail, multifamily, and sp...
LoopNet
The largest commercial real estate marketplace in the United States, surfacing CRE listings for sale and lease alongside CoStar-sourced analytics.
Apartments.com Network
Residential rental marketplace network including Apartments.com, ForRent.com, and Westside Rentals, providing listings, leads, and advertising to multifamily owners and managers.
Homes.com
Residential for-sale and rental marketplace operating agent-first branding and search, paired with the Homesnap mobile and agent tooling.
Homesnap
Mobile residential real estate search and agent productivity application that integrates with MLSs and Homes.com.
Ten-X
Online commercial real estate transaction and auction platform for buyers and sellers of CRE assets.
BizBuySell
Online marketplace for buying and selling small and mid-sized businesses, with broker tools and financing partners.
STR (Smith Travel Research)
Hotel benchmarking, performance data, and analytics provider serving the global lodging industry.
Visual Lease
Lease management and lease accounting platform for corporate and real estate tenants.
Matterport
3D spatial data capture platform used to digitise real estate, retail, and built-environment spaces, integrated across CoStar's marketplaces.
OnTheMarket
UK residential property portal acquired by CoStar Group, providing for sale and to let listings with agent tooling.
Emporis
Global building data and imagery provider covering high-rise and commercial structures.
Domain Group
Australian residential real estate marketplace and media company in which CoStar Group acquired a majority stake.
Land.com / Lands of America
Land-for-sale marketplace network covering rural, ranch, recreational, and development land in the United States.
Scroll within the panel for all 14 ·
Pricing Plans 1
Pricing is part of the interface. Machine-readable plans tell you what a tier costs and includes before you commit — one of the things the Kin Score reads for access clarity — renamed from commercial clarity in rubric 0.12, because a free statutory interface has access terms and no commercial ones.
Published pricing tiers and plan structures.
Costar Plans Pricing
PLANSRate Limits 1
Rate limits are the difference between a demo that works and a production integration that doesn't fall over. Publishing them is an operational-transparency signal — and a hard requirement for any agent that plans its own throughput.
Documented rate limits and quota policies.
Costar Rate Limits
RATE LIMITSFinOps 1
Cost, billing, and metering signals let a buyer model the financial operations of an API before it's live. We profile them for the same reason we profile pricing: the money is part of the contract.
Cost, billing, and metering signals for API financial operations.
Costar Finops
FINOPSSecurity 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.
Resources
Every other property we hold for CoStar Group — 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.
Access & Security 2
Authentication, authorization, and security posture
Commercial 1
Pricing, plans, and the legal terms of use
Company 4
The organization behind the API
← All providers · Data indexed from github.com/api-evangelist/costar · machine-readable index on apis.io
This is an independent, third-party profile of CoStar Group, published by API Evangelist. We do not operate, host, resell, or support these APIs, and we are not affiliated with or endorsed by the company unless stated above. Everything here is built from publicly available information — the company's own site, developer portal, documentation, public repositories, and the specifications it publishes for public use. Nothing is obtained by breaching a system, defeating an access control, or using credentials.
The Kin Score and Agent Readiness rating are independently calculated assessments of a company's public API artifacts, scored against a published rubric. They are not certifications, endorsements, security assessments, or audits.
Corrections, re-scores, and removal are free — no partnership or purchase required, and you do not need to justify the request. A removed company is recorded as unrated, never scored zero for having asked. Acknowledgement within one business day; removal within two.
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you will get a person, not a form — we will tell you exactly which public URLs this profile was built from.