Project Open Data (data.json) Catalog API
Every U.S. federal executive branch agency is required by the Open Government Data Act of 2018 (and predecessor OMB M-13-13) to publish a public enterprise data inventory as a JSON document at /data.json on its primary domain. The format follows the DCAT-US 1.1 schema (Project Open Data Metadata Schema), an extension of W3C DCAT. Data.gov harvests these /data.json endpoints on a regular cadence and ingests records into the central CKAN catalog. The schema defines a Catalog containing Dataset records with required fields (title, description, keyword, modified, publisher, contactPoint, identifier, accessLevel, bureauCode, programCode) and optional distribution records (downloadURL, accessURL, mediaType, format).