The REST API
Visitor profiles and custom columns, user lists and membership, ranked interests, product and content catalogs, campaigns, actions, placeholders, goals, events, forms and aggregated results.
Server-side SDKs
Node, PHP and Python ports of one endpoint, with a shared written contract so all three behave identically — sessions, decisions, events and purchases in a single call.
Mobile SDKs
Android and iOS handle the session lifecycle, report navigation and interactions, and render returned content into a view you position.