/**
 * Build the Authorization header for quonfig API requests.
 * Format: Basic base64("1:{sdkKey}")
 */
export declare const authHeader: (sdkKey: string) => string;
/**
 * Build the standard headers for quonfig API requests.
 * Note: We intentionally omit X-Quonfig-Client-Version to avoid
 * CORS preflight issues in browsers. Custom headers trigger OPTIONS
 * preflight which requires server-side CORS configuration.
 */
export declare const headers: (sdkKey: string, _clientVersion: string) => {
    Authorization: string;
};
/**
 * Per-leg hard fetch deadline (ms). Lowered from 10s to 3s with the parallel
 * hedge (spec 5e): a page loaded against a hung primary used to wait the full
 * 10s before even trying the secondary. 3s sits above a cold-start / mobile
 * primary (so a slow-but-alive primary isn't clipped) but far below the old
 * wall. It must stay ABOVE DEFAULT_HEDGE_DELAY so a hedged secondary leg gets
 * its own budget. Mirrors sdk-go's DefaultConfigFetchTimeout (3s).
 */
export declare const DEFAULT_TIMEOUT = 3000;
/**
 * How long the hedge waits for the primary leg before ALSO firing the
 * secondary in parallel (ms). Fire-on-slow, never on a fast primary success,
 * so the secondary is contacted only for the bounded slice of requests slower
 * than this delay (spec 5e). Mirrors sdk-go's DefaultConfigFetchHedgeDelay (2s).
 *
 * Raising this toward the primary's measured p99 reduces how often the
 * secondary is touched; the reject-older guard (spec 5f) makes firing it early
 * harmless either way — the depth-1 secondary's generation=1 is rejected for an
 * established client, so an early hedge can never regress or flap it.
 */
export declare const DEFAULT_HEDGE_DELAY = 2000;
/**
 * Default Quonfig domain. Used when no explicit URL options are supplied
 * and `QUONFIG_DOMAIN` is not set in `process.env`.
 */
export declare const DEFAULT_DOMAIN = "quonfig.com";
export type DomainOptions = {
    domain?: string;
};
/**
 * Resolve the active Quonfig domain.
 *
 * Order (highest wins):
 *   1. `options.domain` — the documented browser path (single knob that
 *      flips api + telemetry URLs in lockstep, set via `init({ domain })`
 *      or @quonfig/react `<QuonfigProvider domain=...>`)
 *   2. `process.env.QUONFIG_DOMAIN` — useful Node-side / SSR / build-time
 *      inlining; not reliably present at runtime in browsers
 *   3. Hardcoded default `"quonfig.com"`
 *
 * The env-var read is guarded so a pure browser runtime (where `process`
 * does not exist or is stubbed) does not throw.
 */
export declare const getDomain: (options?: DomainOptions) => string;
/**
 * Default ordered list of API base URLs, derived from the active domain.
 * Frontend SDK does NOT open SSE — only the eval-with-context HTTP endpoint
 * is hit, so we ship both primary and secondary as failover targets.
 */
export declare const getDefaultApiUrls: (options?: DomainOptions) => string[];
/**
 * Default telemetry base URL, derived from the active domain.
 */
export declare const getDefaultTelemetryUrl: (options?: DomainOptions) => string;