/**
 * ContextBudgetGuard
 *
 * Tracks aggregate token usage across all context sources per session.
 * Prevents context window stuffing and many-shot jailbreaking attacks.
 *
 * Why this exists: Anthropic's research shows 256 faux dialogues in a single
 * prompt override safety training. Individual guards have per-source limits,
 * but nothing tracks the AGGREGATE context size. An attacker can fill the
 * context window to push out system prompts.
 */
export interface ContextBudgetGuardConfig {
    /** Max total estimated tokens across all sources (default: 8000) */
    maxTotalTokens?: number;
    /** Tokens reserved for system prompt - never consumed by user content (default: 2000) */
    systemPromptReserve?: number;
    /** Max conversation turns per session (default: 50) */
    maxTurnsPerSession?: number;
    /** Max number of similar-structure messages before flagging (default: 5) */
    maxSimilarMessages?: number;
    /** Custom token estimator (default: Math.ceil(text.length / 3.5)) */
    tokenEstimator?: (text: string) => number;
}
export interface ContextBudgetResult {
    allowed: boolean;
    reason?: string;
    violations: string[];
    budget: {
        used_tokens: number;
        remaining_tokens: number;
        system_reserve: number;
        sources: Record<string, number>;
        turn_count: number;
    };
    many_shot_detected: boolean;
}
export declare class ContextBudgetGuard {
    private config;
    private sessions;
    constructor(config?: ContextBudgetGuardConfig);
    /**
     * Track context from any source and check budget
     */
    trackContext(sessionId: string, source: string, content: string, requestId?: string): ContextBudgetResult;
    /**
     * Get current budget status for a session
     */
    getSessionBudget(sessionId: string): ContextBudgetResult["budget"] | null;
    /**
     * Reset session budget
     */
    resetSession(sessionId: string): void;
    /**
     * Destroy and release all resources
     */
    destroy(): void;
    private detectManyShotPattern;
    private getOrCreateSession;
}