/**
 * Rate Limiting Middleware
 *
 * Uses Upstash Redis for distributed rate limiting.
 * Supports per-API-key and per-IP limiting with configurable tiers.
 */
import type { Context, Next } from "hono";
export interface RateLimitConfig {
    /** Override requests per minute */
    requestsPerMinute?: number;
    /** Skip rate limiting entirely */
    skip?: boolean;
    /** Custom identifier function */
    getIdentifier?: (c: Context) => string;
}
export interface RateLimitInfo {
    limit: number;
    remaining: number;
    reset: number;
}
/**
 * Rate limiting middleware using Upstash Redis.
 *
 * Limits requests based on API key (from X-API-Key header) or IP address.
 * Returns 429 Too Many Requests when limit exceeded.
 *
 * Response headers:
 * - X-RateLimit-Limit: Total requests allowed in window
 * - X-RateLimit-Remaining: Requests remaining
 * - X-RateLimit-Reset: Unix timestamp when limit resets
 */
export declare function createRateLimitMiddleware(config?: RateLimitConfig): (c: Context, next: Next) => Promise<(Response & import("hono").TypedResponse<{
    error: string;
    retryAfter: number;
}, 429, "json">) | undefined>;
/**
 * Check rate limit status without consuming a request.
 * Useful for showing remaining quota to users.
 */
export declare function getRateLimitStatus(identifier: string): Promise<RateLimitInfo | null>;
/**
 * Reset rate limit for an identifier.
 * Use with caution - mainly for admin/testing purposes.
 */
export declare function resetRateLimit(identifier: string): Promise<boolean>;
export declare const rateLimitMiddleware: (c: Context, next: Next) => Promise<(Response & import("hono").TypedResponse<{
    error: string;
    retryAfter: number;
}, 429, "json">) | undefined>;