import type { LogLevel, LoggerService } from '@nestjs/common';
/**
 * A NestJS LoggerService that writes all output to process.stderr.
 *
 * Use this when running an MCP server over STDIO transport.
 * The MCP protocol reserves stdout exclusively for JSON-RPC messages;
 * any log output on stdout corrupts the protocol stream.
 *
 * @example
 * // Standalone STDIO app
 * const app = await NestFactory.createApplicationContext(AppModule, {
 *   logger: new StderrLogger(),
 * });
 *
 * // Mixed HTTP + STDIO app
 * const app = await NestFactory.create(AppModule, {
 *   logger: new StderrLogger(),
 * });
 */
export declare class StderrLogger implements LoggerService {
    private readonly levels;
    constructor(options?: {
        logLevels?: LogLevel[];
    });
    private write;
    log(message: unknown, context?: string): void;
    error(message: unknown, trace?: string, context?: string): void;
    warn(message: unknown, context?: string): void;
    debug(message: unknown, context?: string): void;
    verbose(message: unknown, context?: string): void;
    fatal(message: unknown, context?: string): void;
    setLogLevels(levels: LogLevel[]): void;
}
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