/**
 * MCP Rate Limiter
 *
 * Fixed-window rate limiter scoped by tenant + tier.
 * Supports pluggable storage backends via RateLimitStore:
 * - InMemoryRateLimitStore (default, Map-backed)
 * - PGliteRateLimitStore (SQL-backed, persistent)
 *
 * @example
 * ```typescript
 * // In-memory (default)
 * const limiter = new McpRateLimiter();
 *
 * // PGlite-backed
 * import { PGlite } from '@electric-sql/pglite';
 * import { PGliteRateLimitStore } from './rate-limit-store.js';
 * const db = new PGlite();
 * const limiter = new McpRateLimiter({
 *   store: new PGliteRateLimitStore({ db }),
 * });
 *
 * const result = await limiter.check('tenant-123', 'pro');
 * if (!result.allowed) {
 *   throw new Error(`Rate limited. Retry after ${result.resetMs}ms`);
 * }
 * ```
 */
import { type RateLimitStore } from './rate-limit-store.js';
export interface RateLimitConfig {
    /** Max requests per window */
    maxRequests: number;
    /** Window size in milliseconds */
    windowMs: number;
}
export interface RateLimitResult {
    allowed: boolean;
    remaining: number;
    limit: number;
    resetMs: number;
}
export interface McpRateLimiterOptions {
    /** Tier-based rate limit configuration. */
    limits?: Record<string, RateLimitConfig>;
    /** Storage backend (default: InMemoryRateLimitStore). */
    store?: RateLimitStore;
}
/** Default rate limits per tier. */
export declare const DEFAULT_TIER_LIMITS: Record<string, RateLimitConfig>;
/**
 * Fixed-window rate limiter scoped by tenant + tier.
 * Accepts a pluggable RateLimitStore for different storage backends.
 */
export declare class McpRateLimiter {
    private store;
    private limits;
    private cleanupInterval;
    constructor(options?: McpRateLimiterOptions);
    /**
     * Check if a request is allowed and consume one token if so.
     * Returns quota information including remaining requests and reset time.
     */
    check(tenantId: string, tier: string): Promise<RateLimitResult>;
    /** Override limits for a specific tier. */
    setTierLimit(tier: string, config: RateLimitConfig): void;
    /** Clean up expired window entries. */
    private cleanup;
    /** Dispose the rate limiter, clearing the cleanup timer and all windows. */
    dispose(): Promise<void>;
}
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