import { AuthenticatedUser } from "../lib/types";
/**
 * Validate an API key and return the authenticated user.
 * Results are cached for 60 seconds.
 */
/** Structured validation error for API key format issues */
export declare class ApiKeyFormatError extends Error {
    constructor(message: string);
}
export declare function validateApiKey(apiKey: string): Promise<AuthenticatedUser | null>;
export declare function getApiKeyAuthCacheSize(): number;
/**
 * Extract API key from Authorization header.
 */
export declare function extractApiKey(authHeader: string | undefined): string | null;
//# sourceMappingURL=apiKeyAuth.d.ts.map