Attom MCP server

ATTOM — Property and Real Estate Data

ATTOM (formerly Onboard) is a commercial property data provider covering 99% of US single- and multi-family parcels. The data behind tax records, valuations (AVMs), comparables, ownership history, neighborhood demographics, and risk overlays (flood, wildfire). It's what most real-estate analytics products sit on top of.

Part of Pipeworx — an MCP gateway connecting AI agents to 1679+ live data sources.

Why this matters for AI agents

Anything about a specific US property — its value, taxes, sale history, who owns it, what it sold for last — flows from ATTOM. Commercial-grade data with national coverage; competing public sources (Zillow public data, county assessor sites) have spotty coverage and inconsistent schemas.

Common use cases:

• AVM lookup. "What's 123 Main St worth?" → attom_avm({address1, address2}) → automated valuation with confidence band.
• Tax history. "What's the property tax been?" → attomtaxhistory → annual tax assessments.
• Comps. "What have similar homes sold for nearby?" → attom_comps.
• Market context. "What's typical for this metro?" → attommarketstats.

For a one-call combined view, use the Housing Vertical's housingpropertyreport compound — wraps ATTOM AVM + tax + Altos market + FEMA flood.

Auth

ATTOM is a paid commercial API. Two options:

1. BYO key: get an ATTOM key directly at https://api.developer.attomdata.com, pass via _apiKey:

attom_avm({
     address1: "123 Main St",
     address2: "Denver, CO 80202",
     _apiKey: "your-attom-api-key"
   })

1. Pipeworx Housing Vertical: subscribe at pipeworx.io/account and Pipeworx fronts the ATTOM relationship. No _apiKey needed; calls bill against your Pipeworx account.

The vertical option is simpler if you're using ATTOM alongside FRED, BLS, Altos, and FEMA — they're all packaged.

Coverage and freshness

• Coverage: ~155M residential parcels, plus commercial records in major metros. National.
• Update cadence: County assessor data updates as counties update their records (varies — most update annually, some more often). AVMs recalibrate monthly. ATTOM is the lag, not Pipeworx.
• Address normalization: ATTOM is finicky about addresses. Use address1 for the street part and address2 for "City, ST ZIP" — works most consistently. Apartment numbers, abbreviations, and PO boxes all behave subtly differently.

Common pitfalls

• AVM bands matter. A point estimate without the confidence band is misleading. Always report both. ATTOM gives you valueLow / valueHigh — pass both through to the user.
• Tax history isn't always current-year. Counties report at different cadences. The most-recent year in attomtaxhistory may be 6–18 months behind reality.
• Comps need filters. Default attom_comps returns recent sales near the address but doesn't filter by similarity. Filter client-side by sqft, beds, baths, and date range to make comps useful.
• Commercial vs. residential. Most ATTOM tools default to residential. Commercial properties have different schemas; use the dedicated commercial endpoints (or the Housing Vertical's compound, which handles both).
• Rural and tribal land. Coverage gaps exist for some rural counties and tribal lands. If a valid-looking address returns no match, the parcel may not be in ATTOM's coverage.

Quick Start

Add to your MCP client (Claude Desktop, Cursor, Windsurf, etc.):

{
  "mcpServers": {
    "attom": {
      "url": "https://gateway.pipeworx.io/attom/mcp"
    }
  }
}

What this endpoint actually serves

Shortened. The full README is on GitHub.