What is Svelte's context API?

Svelte's context API provides a way to pass data deep into the component tree without prop drilling, but unlike stores, context is scoped to a component subtree (not global). setContext: sets a value in the current component's context, available to all descendants: import { setContext } from 'svelte'; setContext('user', currentUser);. getContext: retrieves a value from the nearest ancestor that set it: import { getContext } from 'svelte'; const user = getContext('user');. Context is not reactive by default — if you need reactive context, store a writable store in context. Use cases: theme providers, user context for deeply nested components, component library configuration. Difference from stores: stores are application-global; context is component-tree-scoped (multiple instances of a component each get their own context). Context values are only accessible during component initialization.