/**
 * Rate Limiter - Token Bucket Algorithm (PostHog-style)
 *
 * Prevents runaway loops from flooding the server with events.
 * Uses a token bucket algorithm with configurable rate and burst limits.
 *
 * Features:
 * - Configurable events per second (default: 10)
 * - Configurable burst limit (default: 100)
 * - Token replenishment over time
 * - Warning event when rate limited
 */
export interface RateLimitBucket {
    tokens: number;
    last: number;
}
export interface RateLimiterConfig {
    eventsPerSecond?: number;
    eventsBurstLimit?: number;
    persistence?: {
        get: (key: string) => RateLimitBucket | null;
        set: (key: string, value: RateLimitBucket) => void;
    };
    captureWarning?: (message: string) => void;
}
export declare class RateLimiter {
    private eventsPerSecond;
    private eventsBurstLimit;
    private lastEventRateLimited;
    private persistence?;
    private captureWarning?;
    constructor(config?: RateLimiterConfig);
    /**
     * Check if the client should be rate limited
     *
     * @param checkOnly - If true, don't consume a token (just check)
     * @returns Object with isRateLimited flag and remaining tokens
     */
    checkRateLimit(checkOnly?: boolean): {
        isRateLimited: boolean;
        remainingTokens: number;
    };
    /**
     * Check if an event should be allowed (consumes a token if allowed)
     */
    shouldAllowEvent(): boolean;
    /**
     * Get remaining tokens without consuming
     */
    getRemainingTokens(): number;
}