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Multifamily loan sizing as an MCP server

Ask Claude, ChatGPT or another assistant how much an apartment building can borrow and it can answer with this site's engine: Fannie Mae, Freddie Mac and HUD sized side by side under their published limits, each answer with its source. Free, read-only, no key.

Add it to your AI assistant

Server URL (Streamable HTTP, no key, read-only):

https://multifamily.online/mcp
Claude (claude.ai and the desktop app)
Settings, then Connectors, then Add custom connector. Paste the URL and save. No sign-in is needed.
ChatGPT
Settings, then Apps and Connectors. Turn on Developer mode under Advanced, choose Create, paste the URL and set authentication to none.
Grok
grok.com, then Connectors, then New connector, then Custom. Paste the URL.
Perplexity
Settings, then Connectors, then Add custom connector, then MCP. Paste the URL and choose no authentication.
Mistral Le Chat
Intelligence, then Connectors, then Add connector, then Custom MCP connector. Paste the URL.

Claude Code:

claude mcp add --transport http multifamily-online https://multifamily.online/mcp

Cursor (~/.cursor/mcp.json) and other clients that read mcpServers:

{
  "mcpServers": {
    "multifamily-online": {
      "url": "https://multifamily.online/mcp"
    }
  }
}

VS Code (.vscode/mcp.json):

{
  "servers": {
    "multifamily-online": {
      "type": "http",
      "url": "https://multifamily.online/mcp"
    }
  }
}

Gemini CLI (~/.gemini/settings.json):

{
  "mcpServers": {
    "multifamily-online": {
      "httpUrl": "https://multifamily.online/mcp"
    }
  }
}

Menu names change as the apps update. If a step has moved, look for "connectors" or "MCP" in the app's settings.

Tools

ToolWhat it returnsTry asking
compare_programsRuns the comparison app on one building: for each Fannie Mae, Freddie Mac and HUD program, whether it fits or why not, max loan by LTV and by DSCR, the limit that binds, the payment (with HUD MIP), term and warnings, ranked by max loan.I have a 48-unit building worth $9.4 million with $610,000 NOI. How much could I refinance with Fannie, Freddie or HUD?
get_program_termsOne program or all: max LTV or LTC, minimum DSCR, term, prepayment, recourse, structure and the agency document it comes from, with its date.What are the max LTV and minimum DSCR for a HUD 223(f) loan?
get_treasury_yieldsThe 5-, 7- and 10-year Treasury yields and SOFR the app builds its example rate on, with as-of dates and publisher links.What is the 10-year Treasury yield agency multifamily rates are priced off today?

Discovery file: /.well-known/mcp.json. The formulas are on how it sizes, and every limit with its document and date is on program terms.

License and attribution

Treasury and New York Fed data stay under their publishers' terms. The program-book compilation is CC BY 4.0: credit "Data: Stackup (multifamily.online)" with a link. Stackup is published by Janover Capital LLC and is not affiliated with HUD, FHA, Fannie Mae, Freddie Mac or any government agency. Nothing returned is a quote, approval or commitment to lend.

Questions people ask

Is there a cost or an API key?

No. The server is free, read-only and needs no key or sign-in. It never sends your numbers to a lender or to the desk; it only sizes them.

Does it give the same answer as the app?

Yes. compare_programs runs the same sizing engine and the same program book as the app on the home page, with the same defaults: each program's maximum amortization, a 10-year hold, and the 10-year Treasury plus an example 1.75% spread unless you give a rate.

Is the result a quote?

No. It is an estimate from your inputs and each program's published limits. Lenders size on their own underwriting, appraisal and rate, and can be stricter than the published maximums.

Questions or a data error: hello@multifamily.online. Privacy and terms.

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