Start here when you need to understand how SDK features work, why they behave a certain way, or how
the implementation makes runtime decisions. Concepts complement package README files and guides;
they are not the first stop for installation or setup commands.
Available concepts
Core state management - explains how CoreStateful stores internal
state using signals, why that state is protected from outside interference, and which
consumer-facing surfaces — observables, interceptors, and lifecycle methods — are the correct way
to observe and influence state.
Entry personalization and variant resolution -
explains how the SDK resolves a Contentful baseline entry to the selected entry variant, including
data model expectations, fallback behavior, resolution paths, and preview overrides.
Interaction tracking in Web SDKs - explains how
@contentful/optimization-web and @contentful/optimization-react-web detect browser entry
views, clicks, hovers, Custom Flag views, page events, and custom events, including consent,
profile, DOM, and delivery mechanics.
Interaction tracking in Node and stateless environments -
explains what the Node SDK can track from a stateless server runtime, when browser observation is
required, how the Web SDK can track server-generated HTML without owning personalization, and what
a manual client-side tracking implementation must replace.
Profile synchronization between client and server -
explains how profile identity, profile data, cookies, browser storage, and Experience API
responses work together when Node and Web SDK runtimes share a visitor journey.
React Native SDK Interaction Tracking Mechanics -
explains how the React Native SDK observes, gates, and emits tracking events, covering event
types, the viewport state machine, default thresholds, consent gating, scroll context, screen
tracking paths, and the configuration resolution order