HMDA — US mortgage applications at loan level

Every mortgage application US lenders were required to disclose under the Home Mortgage Disclosure Act, 2018–2025: who applied, what happened, for how much, by lender, county and census tract. Roughly 99 fields per record.

Part of Pipeworx — an MCP gateway connecting AI agents to 1683+ live data sources.

This is the dataset behind fair-lending analysis — it exists so that denial patterns across race, ethnicity, sex and geography are checkable rather than asserted.

Auth

None. The CFPB/FFIEC Data Browser API is public and keyless.

Tools

Lenders are identified by LEI, not name — resolve_entity({type:"company"}) maps a name to one. Counties are 5-digit FIPS (06037, not "Los Angeles").

Why there is no ingest

This pack was specced as a bulk load: ~15M records a year, 12–18 GB of Postgres, an R2/Postgres column split, possibly a database tier upgrade.

None of it was needed. The Data Browser API answers the reverse queries directly and keylessly — view/aggregations groups on any dimension you pass, view/csv streams loan-level rows — so the pack proxies live data and hosts nothing. Measured 2026-08-25.

The ticket's blocker was that ffiec.cfpb.gov/static/prod/snapshot-data/… returns HTTP 200 with a 3 KB SPA shell and the S3 path 403s. Both are true, and neither matters: the bulk files are not the interface. The API is documented at /documentation/api/data-browser/.

Caveats worth passing to a user

• HMDA is a disclosure regime, not a census of lending. Institutions below the reporting thresholds never appear. A lender absent from a year did not file; that is not the same as doing no lending.
• A denial is the lender's coded reason, not an adjudicated finding. The data supports asking whether patterns differ across groups; it does not by itself establish why.
• Dollar volume is the sum of loan amounts, not balances outstanding.
• Lender identity is a filter upstream, not a grouping. You can ask what one lender did in a county; the API cannot ask a county to rank its lenders. hmda_lenders_in_county does it by reading the county's records directly, which is bounded — a very large county is sampled and the response says so. A complete ranking needs a precomputed lender-by-county aggregate (~775k rows/year, tens of MB), which this pack deliberately does not carry.

Data source

CFPB / FFIEC HMDA Data Browser API — https://ffiec.cfpb.gov/v2/data-browser-api/. Public domain, US federal government work.

Quick Start

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

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

What this endpoint actually serves

tools/list at https://gateway.pipeworx.io/hmda/mcp returns the tools in the table above plus the shared Pipeworx meta-tools — ask_pipeworx, discover_tools, search_within, remember/recall and the rest of the gateway-wide set. So the tool count you see is larger than this table: a single-pack endpoint currently lists roughly 30 shared tools alongside the pack's own. The connection's initialize response states its exact scope, and is the authoritative answer for a given day.

This is deliberate, not multiplexing by accident. The meta-tools are what let a scoped connection answer a question this pack does not cover — via ask_pipeworx, which routes across the whole catalog — without you adding a second MCP server. There is currently no way to mount a pack endpoint without them; if the extra schemas cost you more context than the routing is worth, connect to the full gateway once rather than to several pack endpoints.

Or connect to the full Pipeworx gateway to get every pack's tools listed directly, instead of just this one's:

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

Both URLs reach the same gateway and the same 1683+ data sources. The only difference is which pack's tools are listed directly; ask_pipeworx reaches all of them from either one.

No MCP client? Call it over HTTP

curl -X POST https://gateway.pipeworx.io/v1/tools/hmda_lender_activity \
  -H 'Content-Type: application/json' \
  -d '{"lei":"549300FGXN1K3HLB1R50","year":2023,"county":"11001"}'

No account needed for the first calls. Inspect any tool: GET https://gateway.pipeworx.io/v1/tools/hmda_lender_activity. Find one: POST https://gateway.pipeworx.io/v1/tools/search_packs with {"query":"..."}.

Standalone (no gateway account)

This package also runs as a local stdio MCP server — no Pipeworx account, no gateway round-trip:

{
  "mcpServers": {
    "hmda": {
      "command": "npx",
      "args": ["-y", "@pipeworx/mcp-hmda"]
    }
  }
}

Or run it directly to confirm it starts:

npx -y @pipeworx/mcp-hmda

It speaks MCP over stdin/stdout and answers initialize/tools/list/tools/call for only this pack's tools — none of the shared meta-tools the gateway connection above adds. Same source, same tools, no ask_pipeworx routing.

Using with ask_pipeworx

Instead of calling tools directly, you can ask questions in plain English — this works on the pack endpoint above as well as on the full gateway:

ask_pipeworx({ question: "your question about Hmda data" })

The gateway picks the right tool and fills the arguments automatically.

More

• Docs and guides
• pipeworx.io

License

MIT