/**
 * Bootstrap init helpers — token decode, host resolution, browser metadata
 * collection, env var resolution, segment cache, and geo data fetching.
 */
/**
 * Get environment variable, supporting both Vite and Next.js patterns.
 * CSP-safe: no eval() is used. Vite env access is resolved at build time
 * via the __VITE_IMPORT_META_ENV__ define.
 */
export declare function getEnvVar(name: string): string | undefined;
/**
 * Load cached segment attributes from localStorage.
 * Returns cached values for instant Phase 1 evaluation.
 */
export declare function loadCachedSegmentAttributes(): Record<string, boolean>;
/**
 * Save segment attributes to localStorage for faster future loads.
 */
export declare function cacheSegmentAttributes(attrs: Record<string, boolean>): void;
/**
 * Extract segment flags (in_segment_*) from PostHog feature flags.
 */
export declare function extractSegmentFlags(allFlags: Record<string, boolean | string> | undefined): Record<string, boolean>;
/**
 * Collect browser metadata for instant GrowthBook targeting.
 * This data is available synchronously from browser APIs — no network call needed.
 * Only non-empty values are included.
 */
export declare function collectBrowserMetadata(): Record<string, string | string[]>;
export declare const GEO_DEFAULT_HOST = "https://geo.syntrologie.com";
/**
 * Fetch geo data from the Cloudflare Worker, with localStorage caching.
 * Returns cached data immediately on subsequent visits. Best-effort — never blocks init.
 */
export declare function fetchGeo(geoHost: string): Promise<Record<string, string>>;
