U.S. Census Bureau requires API key for all Census Data API requests; approved email domains needed to activate

An agency official for the U.S. Census Bureau announced that the bureau now requires an API key for all queries to the Census Data API and urged data users to register for a key before making requests. The official said the key is a security measure intended to protect both the bureau and data users and that each key is a unique alphanumeric string tied to an email address.

The official outlined the request process on the Census developer page: locate the "Request a Key" section, click through to the sign-up page, enter an organization name and an email address, check the terms-of-service box, and click the request-key button. "When you request an API key, you will need to include your email address," the official said.

Users were advised to choose an email they check regularly and will retain access to because the bureau will use it to notify them of any dataset issues or changes. The official listed allowed email extensions: ".com, .net, .org, .gov, or .edu," and warned that keys requested with other extensions "may receive an API key, but you will be unable to activate and use it." The official recommended entering a recognizable organization name; if a requester is using the key for personal projects, they may enter a descriptor such as "personal use" in the organization field.

To include the key in queries, the official instructed users to add "&key=" followed by the full API key string to each API request. "If you are making queries directly to the API using your web browser, you will add ampersand key equals to it, and insert the entire API key character string after the equals sign," the official said. A functioning key will return data; syntax errors or missing characters in the key string will generate error messages.

The bureau said the request and activation process is automated, and users should allow a few minutes for the system to update between steps. If users try to activate the key too soon they may receive an error; the official advised waiting a few minutes and trying again. "If any step in the process isn't successful after 30 minutes, please reach out to the email address below," the official said.

The announcement concluded by directing users to the Census developers page for additional guidance and support contact information. The bureau did not state any changes to data availability or pricing in this announcement.