There is no official CoStar connector in Claude. CoStar does not publish a public API you can point Claude at. We will not build a login-sharing agent, a scraper, or a RAG pipeline on licensed CoStar data. That is not a product gap. The data vendor does not want that product to exist.
The team already pays for both. They want comps, sales, and market context without copying screens into a chat window.
If you open Customize → Connectors and search for CoStar, you will not find it. That is not a Claude bug. CoStar is not in the catalog because CoStar does not offer that kind of access.
What people are really asking
When a principal buys Claude seats, CoStar is the first system they want wired in. Buying Claude for a CRE team is not AI adoption. Buying CoStar plus Claude is not adoption either. Adoption is a workflow that produces work the team will actually use, on a cadence, with a person who owns the output.
What “connect” would actually mean
This is not legal advice. Their signed license binds them. CoStar’s public Terms of Use (last revised July 6, 2026) are the source for the three refusals below.
- Share the login with Claude or an AI agent. Do not. The terms say passcodes may not be shared with third-party AI services, including, without limitation, artificial intelligence agents.
- Scrape it. Also no. The same terms prohibit scraping, data-mining, extraction tools, robots, and spiders. A custom CoStar connector that pretends to be a user is the thing teams ask altr to build, and the thing altr will not build.
- Export a slice and paste it into Claude. Do not treat that as fine either. Public terms also say you may not expose the licensed product to AI tools outside CoStar, or use data generated from it as input to generative AI or retrieval-augmented generation.
“Just connect it” is not a product gap Claude forgot to fill. The data vendor does not want that product to exist.
What to do instead
Connect Claude to systems the team owns. CRM. Yardi. The files already on disk. That is the connectors work, and it is allowed because those systems are theirs.
Use public records for comps and owners — county deeds, Sunbiz — through a custom connector, not CoStar. We described that pattern in the connectors note: napkin math still happens, but the automated path is the public source, not a licensed screen.
Put their own process in a Skill using files they already have: an OM, a rent roll from their system, tour notes. Run the file work in Cowork so the model lives on disk. Put the recurring research on Scheduled Tasks against sources they are allowed to automate.
Someone still opens CoStar when they need CoStar. Claude does the repeatable work around it.
This is not saying CoStar is useless or to cancel it. Not legal advice. If Claude only works when someone pastes CoStar into chat, they do not have a CoStar problem. They have a workflow problem.
Do not ask Claude to log into CoStar. Ask it to run the work you are allowed to automate, on a cadence, with a person who owns the output.