/**
 * TokenCostGuard
 *
 * Tracks LLM API token usage and cost per session/user.
 * Enforces financial circuit breaking with hard cost ceilings.
 *
 * Addresses OWASP LLM10: Unbounded Consumption — insufficient controls
 * on resource usage leading to excessive API costs, denial-of-service,
 * or financial exploitation.
 *
 * Real-world context:
 * - A single runaway agent loop can burn $10K+ in API costs in minutes
 * - Deloitte 2026: only 20% of orgs have mature governance for AI spending
 * - LLMjacking: stolen credentials used to run up bills on victim accounts
 */
export interface TokenCostGuardConfig {
    /** Max tokens per session before blocking (default: 100000) */
    maxTokensPerSession?: number;
    /** Max tokens per user across all sessions (default: 500000) */
    maxTokensPerUser?: number;
    /** Max cost in dollars per session (default: 10.0) */
    maxCostPerSession?: number;
    /** Max cost in dollars per user (default: 50.0) */
    maxCostPerUser?: number;
    /** Cost per 1K input tokens in dollars (default: 0.003) */
    inputTokenCostPer1K?: number;
    /** Cost per 1K output tokens in dollars (default: 0.015) */
    outputTokenCostPer1K?: number;
    /** Max single request token count (default: 32000) */
    maxTokensPerRequest?: number;
    /** Alert threshold as percentage of budget (default: 0.8 = 80%) */
    alertThreshold?: number;
    /** Session budget window in milliseconds (default: 3600000 = 1 hour) */
    budgetWindowMs?: number;
}
export interface TokenUsage {
    inputTokens: number;
    outputTokens: number;
    totalTokens: number;
    estimatedCost: number;
}
export interface TokenCostResult {
    allowed: boolean;
    reason?: string;
    violations: string[];
    usage: {
        session: TokenUsage;
        user: TokenUsage;
        request: TokenUsage;
    };
    budget: {
        session_remaining_tokens: number;
        session_remaining_cost: number;
        user_remaining_tokens: number;
        user_remaining_cost: number;
        alert: boolean;
        alert_message?: string;
    };
}
export declare class TokenCostGuard {
    private config;
    private sessionUsage;
    private userUsage;
    constructor(config?: TokenCostGuardConfig);
    /**
     * Track token usage for a request and check against budgets
     */
    trackUsage(sessionId: string, userId: string, inputTokens: number, outputTokens: number, requestId?: string): TokenCostResult;
    /**
     * Get current budget status without recording usage
     */
    getBudget(sessionId: string, userId: string): TokenCostResult["budget"];
    /**
     * Reset session budget
     */
    resetSession(sessionId: string): void;
    /**
     * Reset user budget
     */
    resetUser(userId: string): void;
    /**
     * Destroy and release all resources
     */
    destroy(): void;
    private calculateCost;
    private getOrCreateUsage;
    private cleanEntries;
}