/**
 * Stderr structured logging for the MCP server.
 *
 * The MCP runs over stdio — anything written to stdout corrupts the
 * protocol. All log output goes to stderr. Defaults to silent so default
 * installs don't spam Claude Desktop / Cursor users with noise.
 *
 * Set LOG10X_MCP_LOG_LEVEL to one of: silent, error, warn, info, debug.
 * Default: silent.
 *
 * No external dependency — implemented as a tiny module so the MCP keeps
 * a flat dep graph (only @modelcontextprotocol/sdk + zod).
 */
export declare const log: {
    error: (msg: string, fields?: Record<string, unknown>) => void;
    warn: (msg: string, fields?: Record<string, unknown>) => void;
    info: (msg: string, fields?: Record<string, unknown>) => void;
    debug: (msg: string, fields?: Record<string, unknown>) => void;
};
/** Time a tool call and log its duration at info level on completion. */
export declare function timed<T>(name: string, fn: () => Promise<T>): Promise<T>;