@pipeworx/census

Connect: https://gateway.pipeworx.io/census/mcp · Install: one-click buttons

Tools: 5

The official US Census Bureau data: decennial census, American Community Survey (ACS), economic census, population estimates, housing characteristics, geographic boundaries. National, state, county, place, tract, block-group, and ZCTA-level. Free, no key required for public datasets.

Why this matters for AI agents

Demographics, housing characteristics, economic activity, geographic identifiers — Census is the authoritative source. If an agent is computing per-capita rates, comparing metros, looking up population, or working with FIPS codes, this is where it goes.

Common flows:

• Population for an area. ACS 1-year or 5-year estimates by state/county/place.
• Housing characteristics. Median home value, occupancy, units, age — all in ACS.
• Geographic ID lookup. Place name → FIPS code → boundary geometry.
• Economic Census every 5 years for industry-level economic activity.

Pair with FRED for time-series macro and BLS for labor.

Auth

Most Census APIs are free and unauthenticated, with light rate limits (~500 calls/day per IP). For higher rates, get a key at https://api.census.gov/data/key_signup.html and pass via _apiKey.

Datasets worth knowing

ACS 5-year is what you usually want for current demographics — it’s available at finer geographies than 1-year and updates yearly with rolling 5-year smoothing.

Common pitfalls

• Year-of-coverage vs release year. ACS 5-year 2018-2022 was released in 2023. Don’t conflate.
• Margins of error. ACS includes MOE for every estimate. At small geographies (block group, small tract), MOEs can be larger than the estimate. Always carry MOE through to the user.
• Geography hierarchy. State (01) → County (01001) → Tract (01001020100) → Block Group. The 11-digit tract code is state(2) + county(3) + tract(6).
• Place vs MSA. “Denver” can mean the City and County of Denver, OR the Denver-Aurora-Lakewood Metropolitan Statistical Area (very different boundaries and populations). Disambiguate per use case.
• Population estimates lag the decennial. Between censuses, PEP estimates are extrapolated and revised. The Census Bureau revises previous PEPs each year as they reconcile with births/deaths/migration data.

Tools

• census_acs — Search American Community Survey data by geography and variable code (e.g., B25077_001E for median home value). Returns housing ownership rates, rental costs, vacancy rates, and home values.
• census_building_permits — Check monthly building permits for new residential construction by geography. Returns count of authorized privately-owned housing units and construction activity trends.
• census_housing_starts — Get residential construction pipeline by geography: new starts, units under construction, and completed units. Returns housing supply and activity trends.
• census_homeownership — Check quarterly homeownership rates by geography. Returns percentage of owner-occupied housing units from the Housing Vacancy Survey.
• census_available_datasets — Discover Census datasets and their variables. Returns dataset names, descriptions, and variable codes (e.g., B25001_001E) for querying with other census tools.