Query the SAM.gov Federal Hierarchy Public API to retrieve federal department, agency, and sub-tier organization data for routing grant or contract records

Steps

1. Register a SAM.gov account and generate a Public API key from the Account Details page; re-entering your account password is required to view or generate the key.
2. Call GET https://api.sam.gov/prod/federalorganizations/v1/orgs with your api_key and optional filters such as fhorgname, fhorgtype (Department/Ind. Agency or Sub-Tier), status, or agencycode to search organizations.
3. Use the limit and offset parameters to page through results — the API defaults to 10 records per page with a maximum of 100.
4. To drill into an organization's children, call GET .../org/hierarchy?fhorgid=<id>&api_key=<key>, which returns the immediate next-level hierarchy; this endpoint returns a 400 if the organization has no children.
5. Parse the response's fhfullparentpathid and fhfullparentpathname fields if you need the full department-to-sub-tier lineage rather than just the immediate parent.
6. Test against the staging environment (api-alpha.sam.gov/prodlike) with an alpha.sam.gov-issued key before pointing production traffic at the prod endpoint.