export declare const RIVET_FEATURE_FLAG_USER_KEY_HEADER = "x-rivet-feature-flag-user-key";
type ConfigFeatureFlagUserKeyParams = {
    headers: Record<string, string | string[] | undefined>;
    fallbackEmail?: string;
};
/**
 * Gets the user key used to evaluate request-scoped feature flags.
 */
export declare const getConfigFeatureFlagUserKey: ({ headers, fallbackEmail, }: ConfigFeatureFlagUserKeyParams) => string | undefined;
export {};
//# sourceMappingURL=featureFlagUserKey.d.ts.map