Find the right API
Use search when the broad directory stops being enough. Filter by category, auth, CORS, signup friction, and result freshness until the shortlist becomes obvious.
Start with category and auth when you know the integration shape. Use free, signup, and CORS flags when you are trying to remove setup friction.
Sort by verification or response time when the final call is about reliability, not just category fit.
2 results after 1 active filters. Remove any one below without losing the rest of the cut.
Gmail API
Gmail API lets apps read, send, and organize mail on behalf of a Google account — the core entry point for Workspace integrations.
Gmail Postmaster Tools API
Gmail Postmaster Tools API queries Gmail delivery quality for sender domains — spam rate, authentication (SPF/DKIM/DMARC) pass rate, reputation score.