Agentic Fabriq
US Census Bureau
DATA · DATA & ANALYTICS
Public census datasets, variables, and geographies queried by year.
Connecting US Census Bureau in practice
A Census Data API query is capped at 50 variables and a key is required on every data request, so a wide table cannot be fetched by listing its columns — the group() wildcard is the documented way round it, and one group() call returns all 912 variables of table S0101. Responses are a two-dimensional JSON array whose first row is the column names, so there are no object keys for an agent to bind to.
Rate limits
- Up to 50 variables in a single API query, separated by commas.
- An API key must be used with all data queries made to the Census Data API, passed as a key= parameter in the URL.
Worth knowing
- group(TABLE) returns every variable in a table even when the table has more than 50, which is the only way to read a wide table in one call.
- Some datasets have required variables, and leaving one out returns no results rather than an error naming the missing parameter.
- The vintage and dataset are path segments — /data/2019/acs/acs1 — so moving to a new year is a new URL, and a hard-coded path silently keeps serving last year’s data.
- Because the response is a positional array rather than named objects, a variable added or reordered upstream shifts every column an agent reads.
- The key travels in the query string, so it lands in any access log or proxy trace along the way.
Checked against Census Data API user guide (2026-09-29), Census Data API user guide (PDF), Query Limits (2026-09-29), Census API discovery tool (2026-09-29)
What an agent can do
Each action is granted on its own. An agent allowed to read is not thereby allowed to write, and the scope beside each row is what the acting user must have connected for it to run at all.
Often connected alongside
Put US Census Bureau behind one governed endpoint.
Same permissions, same audit trail, whatever else you connect next.