CrossEngage User Management API v1
Synchronous predecessor to v2, still fully documented and still monitored as its own status-page component. Broader in surface than v2: user attribute definitions (create/list/fetch/delete), lead capture, individual and bulk user management, behavioural event ingestion, and opt-out / blacklist consent status. Fifteen operations, published as an API Blueprint on Apiary. No deprecation or sunset date has been announced.