Production backend code blocks, generated into your project.

// GENERATED FILE: src/blocks/rate-limiter.ts
// Owned by your repository. Zero black-box wrapper dependencies.

import { Request, Response, NextFunction } from 'express';

export interface RateLimitOptions {
  windowMs: number;
  maxRequests: number;
}

export function createRateLimiter(options: RateLimitOptions) {
  const hits = new Map<string, { count: number; resetTime: number }>();

  return (req: Request, res: Response, next: NextFunction) => {
    const ip = req.ip || '127.0.0.1';
    const now = Date.now();
    const record = hits.get(ip) || { count: 0, resetTime: now + options.windowMs };

    if (now > record.resetTime) {
      record.count = 0;
      record.resetTime = now + options.windowMs;
    }

    record.count++;
    hits.set(ip, record);

    if (record.count > options.maxRequests) {
      return res.status(429).json({ error: 'Too Many Requests' });
    }

    next();
  };
}