REST API

The REST API offers structured, hierarchical endpoints covering decennial census data, American Community Survey estimates, and related datasets. Each endpoint responds to standard HTTP methods and returns JSON with consistent pagination controls. Users can filter by geographic area, time period, and variable using query parameters. Schema definitions are versioned and documented per endpoint, ensuring backward compatibility between major releases. This structure mirrors the logical organization of official Census Bureau data products, making it easier for users to translate analytical workflows into code.

All responses include metadata describing the dataset, column meanings, and data limitations. The API supports geospatial filtering through place FIPS codes, ZIP Code Tabulation Areas, and census tracts without requiring spatial joins on the client side. Time-based queries accept YYYY or YYYY-MM formats, aligning with the Bureau’s release cycles. Pagination uses offset and limit parameters, with total record counts included in the response header for progress tracking. Error messages follow RFC 7807 standards for clarity and troubleshooting.

We maintain separate API versions (e.g., v1, v2) deployed in parallel during transitions, with deprecation notices 12 months in advance. Each version corresponds to a specific vintage of underlying statistical content, such as recent decennial or American Community Survey estimates. This decoupling allows developers to lock versions during testing and deploy incrementally. No proprietary logic is added—data values, labels, and coding schemes match official publication specifications exactly.