Census MCP

American Community Survey · Model Context Protocol

U.S. Census data, queryable in conversation.

An MCP server that gives Claude structured access to American Community Survey estimates — geography resolution, variable discovery, and data retrieval, without leaving the chat.

28,475
Variables per vintage
2009–2024
Years covered
3,144
Counties

Getting started

Connect it to Claude

The server is authless and read-only. No account, API key, or local install is required on your end.

https://census-mcp.vercel.app/mcp
  1. In Claude, open Settings → Connectors and choose Add custom connector.
  2. Paste the URL above. Leave the OAuth fields empty.
  3. Enable the connector in a conversation using the + button.
  4. Ask a question, for example: “What is the median household income in DeKalb County, Georgia?”

Using Claude Code instead? Run claude mcp add --transport http census https://census-mcp.vercel.app/mcp

Interface

Tools

list_vintages
Reports which ACS data years are available and which is most recent. Discovered from the Census catalog at runtime, not hardcoded.
resolve_geography
Converts a place name into the FIPS codes required to query data. Returns every candidate rather than guessing — county names repeat across states.
search_columns
Finds variable codes by plain-language keyword across roughly 28,000 variables per vintage, ranked by relevance.
get_data
Retrieves estimates for chosen variables and geography. Supports wildcards for cross-county comparison, with a row cap and explicit truncation notice.

Example

One question, three tools

Recorded from a live session with Claude connected to this server. The server exposes primitives, not answers — Claude decides how to combine them, resolving the place, finding the right variable among 27,000, then fetching the estimate. Connect it above to run queries like this yourself.

What's the median household income in Fulton County, Georgia?
resolve_geography { query: "Fulton County", state: "Georgia" }
Found 1 match(es) (defaulted to 2024, the most recent acs5 vintage):
Fulton County, Georgia — level: county, state FIPS: 13, county FIPS: 121
search_columns { query: "median household income", limit: 5 }
5 match(es) for "median household income", searched 27149 variables:

B19013_001E — Median Household Income in the Past 12 Months
    Estimate > Median household income in the past 12 months
B19013A_001E — ... (White Alone Householder)
B19013B_001E — ... (Black or African American Alone Householder)
B19013C_001E — ... (American Indian and Alaska Native Alone Householder)
B19013D_001E — ... (Asian Alone Householder)
get_data { variables: ["B19013_001E"], state: "13", county: "121" }
ACS acs5 2024, 1 row(s).

NAME                    B19013_001E  state  county
----------------------  -----------  -----  ------
Fulton County, Georgia  95292        13     121
The median household income in Fulton County, Georgia is $95,292. Source: American Community Survey 5-year estimates, 2024 vintage (variable B19013_001E, in 2024 inflation-adjusted dollars).