A market-data MCP in Claude doesn't replace your property manager feeds. Agents need both.
Green Street and ATTOM now put market data, comps and valuations inside Claude and other assistants through MCP. That helps with research and underwriting. It tells you nothing about last night's rent roll at the assets your third-party managers run. That part comes from certified PM feeds in CREx OS.
If I connect Green Street or ATTOM MCP to Claude, do I still need daily feeds from my property managers?
Yes. A market-data MCP server such as Green Street's or ATTOM's lets Claude pull research, market data, comps and valuations about the outside market, but it doesn't hold your rent roll, general ledger or actuals vs budget from each of your third-party property managers. Those come from validated, certified daily PM feeds. An agent asked how your portfolio is doing needs both: the market MCP for context, the operating feeds for what's actually happening in your buildings.
It helps to split the questions. "What are cap rates and comps doing in this submarket?" is a market question, and a research MCP answers it well. "Why did our asset in that submarket miss budget last month?" is an operating question. Only your managers' data can answer it, and only if someone has pulled, mapped and checked that data first.
What is MCP?
MCP (Model Context Protocol) is the open standard that lets Claude, ChatGPT, Gemini and other assistants pull data from outside tools. Anthropic originally developed it. A data provider runs an MCP server. Your firm's admin connects that server to your assistant. After that, the assistant decides which of the provider's tools to call when you ask a question, so nobody has to download a file and paste it into the chat.
MCP is only the plug. What you get depends on what sits behind the server. A research vendor's server gives you that vendor's research. An owner platform's server gives you your own portfolio record, if that record exists and is clean.
What Green Street and ATTOM put in the chat
Both are market and property data vendors. Their MCP servers are good at research and underwriting questions. Details below are from each company's own pages.
GreenStreetAI MCP Server
General availability announced August 11, 2026. At launch it connects Green Street's Research, Company Data, Company Sector Data, Market Data, Market Forecast, Sales Comps and single-property AVM tools, covering the U.S., Canada, Europe and selected Australia depending on the dataset. Works in corporate instances of Claude, ChatGPT and Gemini, for Green Street subscribers.
Green Street announcementATTOM Intelligence MCP Server
ATTOM lists MCP tools for property details, automated valuation models, comparable sales and sales history. Its September 24, 2026 webinar, "AI Agents and MCP for Property Data," covered the MCP server and three agents: Property & Place Insights, Data Analyst and Report Generation, built on ATTOM data such as ownership, valuation and tax records.
ATTOM webinar pageResearch and underwriting
Market fundamentals, forecasts, comps, valuation checks and property records. Context for an IC memo, a hold-sell call or a line in an investor letter. Data about markets and properties, supplied and maintained by the vendor.
What a market MCP can't see
None of this is a knock on Green Street or ATTOM. It just isn't what they sell.
- Your rent roll by unit, as each manager keeps it
- GL and trial balance from each PM's system
- Actuals vs budget by property and by manager
- This week's delinquency, concessions and bad debt
- Your chart of accounts, mapped across every manager
- Proof that yesterday's numbers are complete and tie out, and who approved them
Your operating data sits in each property manager's system, behind their login, in their chart of accounts. Getting it out, mapped, checked and certified every day is a separate job. It's the job described on our property manager integration page, including the six checks that make multi-PM data reliable.
Market MCP vs certified PM feeds
The two answer different questions from different data. You'll want both wired into the same assistant.
| Market / research MCP (e.g. Green Street, ATTOM) | Certified PM operating feeds (CREx OS) | |
|---|---|---|
| Answers questions like | What are cap rates and comps doing in this market? What's this property worth? | What did our assets collect yesterday? Why did NOI miss budget at this asset? |
| Data | Vendor research, market data, forecasts, comps, AVMs, property records | Rent roll, GL, trial balance, budgets and delinquency from each PM |
| Whose data | The vendor's, licensed to you | Yours, held in your managers' systems |
| How it's checked | By the vendor, under its own methodology | On every load against your chart and tie-outs, then certified |
| Freshness | On the vendor's update schedule | Daily per manager, with an as-of time |
| Main use | Research, underwriting, valuation, market context | Monitoring, close, variance, investor and lender reporting |
| How agents reach it | The vendor's MCP server | CREx OS governed record over MCP, API or your warehouse |
How the two work in one agent
A variance question, answered with both servers connected to the same assistant.
Start from your own numbers
The agent pulls actuals vs budget and the rent roll for the asset from CREx OS, certified as of this morning. If a manager's feed failed a check overnight, the agent says so instead of guessing.
Add market context
It calls the market MCP for submarket fundamentals, recent comps or a valuation read on the property.
Separate the manager from the market
Now it can tell a soft market from an operating problem. Occupancy sliding in line with the submarket reads differently from delinquency climbing at one manager while its peers hold.
A person signs off
The draft variance note or IC memo goes to the asset manager. Agentic AM keeps the feeds clean and the approvals on record, so what leaves the building was checked.
Run the same question with only the market MCP and you get a confident read on the market and nothing about your buildings. Run it with only your feeds and you can't tell whether a miss is you or the market. More on where AI analytics tools stop and an owner OS starts: portfolio analytics AI vs CREx OS.
Four questions to ask about portfolio answers
Where did our numbers come from?
Which manager, which system, and as of when. "A spreadsheet someone uploaded" is an answer, just not a good one.
Were they checked first?
Trial balance balanced, rent roll tied to the GL, mapping approved. See data validation.
Can we tell market from ours?
The answer should say which figures came from the vendor and which came from your certified record.
Who approves what goes out?
Agents draft. A named person signs anything that reaches investors or lenders.
The operating side of the same assistant
CREx OS lands certified daily feeds from each third-party property manager, maps them to one chart, validates every load, and exposes the governed record to Claude, Copilot or ChatGPT over MCP. That sits next to whatever market servers your firm already licenses. Your agents get the vendor's view of the market and your own view of the buildings in one conversation.
Agentic AM is how CREx OS is delivered. Data, agents, people and process run together on standing workstreams: feed exceptions, PM chase, close approvals. Performance shows up the day the data lands, and forecasting runs in the background instead of as a spreadsheet fire drill. The usual alternative is hiring another analyst to export PM reports and paste them into the chat. That works until the analyst is out for a week or a manager changes an export.
If you're still sorting out how the feeds work, start with property manager integration and CRE data integration software. For the platform itself, see CREx OS and agent harnesses.
Who this isn't for
If your team only does acquisitions research, a market MCP on its own may be all you need. If one in-house manager runs every asset and your data team already owns a clean record, you may have the operating side covered. The gap shows up when several third-party PMs report to you in different systems.
Frequently asked questions
Do I still need property manager feeds if I use Green Street or ATTOM MCP?
What is an MCP server in commercial real estate?
What does Green Street's MCP server include?
What does ATTOM's MCP server include?
Can Claude read my property managers' data directly?
Should we hire another analyst to feed PM data into our AI tools?
Give your agents your own numbers too.
Bring your PM roster and the AI tools your team uses. We'll show certified feeds and MCP access inside CREx OS.
Book a demo → PM integration