/**
 * Structured logger for MCP server.
 *
 * CRITICAL: All output goes to stderr, NEVER stdout.
 * In stdio transport mode, stdout is the JSON-RPC channel.
 * Any non-JSON-RPC output on stdout breaks the protocol.
 */
export type LogLevel = 'debug' | 'info' | 'warn' | 'error' | 'silent';
export declare function setLogLevel(level: LogLevel): void;
export declare function getLogLevel(): LogLevel;
export declare const logger: {
    debug(message: string, data?: Record<string, unknown>): void;
    info(message: string, data?: Record<string, unknown>): void;
    warn(message: string, data?: Record<string, unknown>): void;
    error(message: string, data?: Record<string, unknown>): void;
};
//# sourceMappingURL=logger.d.ts.map