/**
 * Request-scoped context for structured logging fields (requestId, sessionId, userId, …).
 *
 * Wire `onRequest` / `onResponse` around a handling scope; use `getContext` with
 * `logger.withContext` when you need request fields on log lines.
 *
 *   import { ContextMiddleware } from './middleware/index.js';
 */
import type { LogContext } from '../../utils/logger.js';
export interface RequestContext {
    sessionKey: string;
    userId?: string;
    channel?: string;
    chatId?: string;
    metadata?: Record<string, unknown>;
}
export declare class ContextMiddleware {
    private currentContext;
    private contextDepth;
    private generateRequestId;
    private extractSessionId;
    onRequest(context: RequestContext): string;
    onResponse(): void;
    getContext(): LogContext;
    getRequestId(): string | undefined;
    extendContext(fields: Record<string, unknown>): void;
}