Census Gov Census Data API
Agent-ready OpenAPI document · curated by JenticData EnrichmentAddress ValidationapiKey5 EndpointsREST
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For Agents
Query U.S. Census Bureau demographic, economic, and housing datasets by year, dataset, variable, and geography. Discover available datasets, variables, and geographic levels.
Use for: I need to query American Community Survey 5-year estimates for a county, List all variables available in a specific Census dataset, Find population by ZIP code from the Decennial Census, Retrieve median household income for every state
Not supported: Does not handle address geocoding, EHR records, or tax filing - use for querying U.S. Census Bureau public datasets by variable and geography only.
Jentic publishes the only available OpenAPI specification for the U.S. Census Bureau Data API, keeping it validated and agent-ready. The Census Data API provides access to dozens of public datasets, including the American Community Survey (ACS), Decennial Census, and County Business Patterns. Queries are scoped by dataset vintage (year) and identifier, and can request specific variables aggregated to a chosen geographic level - state, county, tract, ZIP code tabulation area, and more. Five core endpoints cover dataset discovery, variable listing, geography listing, group listing, and the data query itself.
Install Jentic One Beta
Connect the Census Data API to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Census Data API, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fcensus.gov%2Fcensus" | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fcensus.gov%2Fcensus" | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with Census Data API.
Discover every public Census dataset and its vintage via /data
List the variables available in a given dataset and vintage via variables.json
List the geographic levels supported by a dataset via geography.json
Browse variable groups for ACS detailed and subject tables
Run dataset queries scoped by variable list and geography filter via /data/{vintage}/{dataset}
Use Cases
Patterns agents use Census Data API for, with concrete tasks.
★ Demographic Lookup for Geographic Analysis
Civic-tech teams, researchers, and data agents query ACS variables - population, age, race, income - for a chosen geography to feed dashboards or reports. The agent first lists variables for the dataset, then queries /data/{vintage}/{dataset} with a variable list and a geographic filter such as `for=county:*&in=state:06`.
GET /data/2022/acs/acs5 with get=B01003_001E (total population) and for=county:* in state 06 to return California county populations
Variable Discovery for Reporting
A reporting workflow needs to pick the right Census variable codes for a question like 'median household income by tract'. An agent queries variables.json for the target dataset, filters by label, and returns the variable code and concept. This eliminates the manual code lookup against Census documentation.
GET /data/2022/acs/acs5/variables.json and search for 'Median household income' to return the matching variable code and concept
Geography-Aware Address Enrichment
Companies enriching customer addresses with demographic context use the Census API to fetch tract or ZIP-code-level statistics for the geocoded address. The geography.json endpoint confirms which levels the dataset supports, and the data query returns the requested variables for that geography.
GET /data/2022/acs/acs5/geography.json to confirm tract-level support, then query variables for tract 06037201001
AI Agent Integration via Jentic
A research agent uses Jentic to discover Census datasets, load schemas for the variables and data endpoints, and execute calls without holding the API key directly. The agent can chain Census lookups with cBioPortal or CDC ReportStream context for population-normalised public-health analyses.
Use Jentic to search 'query Census ACS data', load the schema for /data/{vintage}/{dataset}, and execute against acs5 for the requested county
Key Endpoints
5 endpoints — jentic publishes the only available openapi specification for the u.
METHOD
PATH
DESCRIPTION
GET
/data
List all available Census datasets
GET
/data/{vintage}/{dataset}
Query a specific Census dataset
GET
/data/{vintage}/{dataset}/variables.json
List variables for a dataset
GET
/data/{vintage}/{dataset}/geography.json
List geographies for a dataset
GET
/data/{vintage}/{dataset}/groups.json
List variable groups
GET
/data
List all available Census datasets
GET
/data/{vintage}/{dataset}
Query a specific Census dataset
GET
/data/{vintage}/{dataset}/variables.json
List variables for a dataset
GET
/data/{vintage}/{dataset}/geography.json
List geographies for a dataset
GET
/data/{vintage}/{dataset}/groups.json
List variable groups
Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring the Census Data API by hand means passing your key as a query parameter and assembling the vintage, dataset, variable, and geography segments for each dataset query yourself. Through Jentic you install once, import the Census Data API from the API Directory, store the key once, and your agent calls it.
Permission scoping
The Census Data API puts the vintage and dataset in the URL path for operations like /data/{vintage}/{dataset}, so a rule can pin your agent to one dataset for its queries. The API is read-only over public datasets, and you choose which query operations it may call.
Credential isolation
Your Census API key is stored once, encrypted, by your own Jentic One instance and injected at execution time. It never enters the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'query Census ACS data' or 'list the variables for a dataset', and Jentic returns the matching Census operation with its input schema so the agent calls the right endpoint without browsing the reference docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Census Data API through Jentic.
Why is there no official OpenAPI spec for the Census Data API?
The Census Bureau publishes documentation pages but not a structured OpenAPI artifact. Jentic generates and maintains this spec so that AI agents and developers can call Census Data API via structured tooling. It is validated against the live API and kept up to date. Get started with Jentic One, the self-hosted execution layer.
What authentication does the Census Data API use?
Census uses an API key passed as the `key` query parameter. Keys are issued for free at api.census.gov/data/key_signup.html and are required above a small unauthenticated threshold. Through Jentic the key is stored in the encrypted vault and appended at execution time.
Can I query American Community Survey data with this API?
Yes. GET /data/{vintage}/{dataset} with dataset paths like acs/acs5 or acs/acs1 runs ACS queries. Use the variables.json endpoint to find the right variable codes and geography.json to find supported geographic levels.
What are the rate limits for the Census Data API?
The Census Bureau allows up to 500 calls per IP address per day without a key, with no public hard cap once a key is registered. Throttle bulk pulls and back off on 429 responses; very large variable-by-tract queries should be batched.
How do I run an ACS query through Jentic?
Search Jentic for 'query Census ACS data', load the schema for GET /data/{vintage}/{dataset}, and execute with the variable list in the get parameter and the geography filter in for/in. The Census key stays in your Jentic One instance.
Is the Census Data API free?
Yes. The Census Data API is free to use. Keys are also free; they exist to track and lift the unauthenticated rate cap.
Can I limit what my agent is allowed to do with the Census Data API?
Yes. Because Jentic One is self-hosted and governed by your own rules, you decide which Census operations your agent may call, so you can grant it the data query at /data/{vintage}/{dataset} while withholding the discovery calls, or the reverse. Since the vintage and dataset sit in the URL path, a rule can pin the agent to a single dataset such as acs/acs5 for a chosen year. The API is read-only over public datasets, so no operation can write or alter Census data. Your Census API key stays with your Jentic One instance and is injected only for the operations you have allowed.
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