Register for a SAM.gov API key at SAM.gov by creating a government or non-government account and requesting a system account with the Entity Management domain; API keys are associated with your account and subject to rate limits
Construct a GET request to the SAM.gov Entity Management API endpoint (https://api.sam.gov/entity-information/v3/entities) with your API key in the api_key query parameter and search criteria such as ueiSAM (Unique Entity Identifier), legalBusinessName, or registrationStatus
Parse the entityData array in the response; each entity record contains coreData (legal name, UEI, CAGE code, physical address), assertions (business type, ownership details), and repsAndCerts (representations and certifications) blocks
Check the registrationStatus field (Active, Expired, or Submitted) and the registrationExpirationDate to confirm the entity has a current SAM.gov registration before awarding a contract or issuing a purchase order
For exclusions screening (debarment), use the separate SAM.gov Exclusions API rather than the entity registration endpoint; an entity with an Active registration may still have an active exclusion that bars award
Handle pagination: the API returns results in pages; use the totalRecords count and the page and pageSize parameters to iterate through all matching entities when the result set exceeds a single page
Known gotchas
The SAM.gov API requires a valid API key and enforces rate limits; exceeding the rate limit returns 429 responses — implement exponential backoff and do not poll the API more frequently than your use case requires
The Unique Entity Identifier (UEI) replaced the legacy DUNS number as the primary entity identifier in SAM.gov; integrations that query by DUNS will not return results, and the DUNS field is no longer populated in SAM.gov records
Entity registration data in SAM.gov is self-reported by the registrant and is not independently verified by the government for every field; registration status (Active) does not guarantee the correctness of other fields such as CAGE code or business size
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp