archivmail/docs/production/rate-limiting.md

Rate Limiting

Prevent abuse, DDoS attacks, and excessive API usage.

When to Add Rate Limiting

• MVP: Optional (focus on features first)
• Production with users: Recommended on auth endpoints and public APIs
• Public-facing APIs: Required

Setup with Upstash Redis

1. Install Dependencies

npm install @upstash/ratelimit @upstash/redis

2. Create Upstash Account

• Go to upstash.com (free tier: 10k requests/day)
• Create a Redis database
• Copy REST URL and token

3. Add Environment Variables

# .env.local
UPSTASH_REDIS_REST_URL=https://xxx.upstash.io
UPSTASH_REDIS_REST_TOKEN=xxx

4. Create Rate Limiter

// src/lib/rate-limit.ts
import { Ratelimit } from '@upstash/ratelimit'
import { Redis } from '@upstash/redis'

export const ratelimit = new Ratelimit({
  redis: Redis.fromEnv(),
  limiter: Ratelimit.slidingWindow(10, '10 s'), // 10 requests per 10 seconds
})

5. Use in API Routes

// src/app/api/example/route.ts
import { ratelimit } from '@/lib/rate-limit'
import { NextRequest, NextResponse } from 'next/server'

export async function POST(request: NextRequest) {
  const ip = request.headers.get('x-forwarded-for') ?? 'anonymous'
  const { success, limit, remaining } = await ratelimit.limit(ip)

  if (!success) {
    return NextResponse.json(
      { error: 'Too many requests' },
      {
        status: 429,
        headers: {
          'X-RateLimit-Limit': limit.toString(),
          'X-RateLimit-Remaining': remaining.toString(),
        },
      }
    )
  }

  // Process request normally...
}

6. Use in Middleware (Global)

// middleware.ts
import { ratelimit } from '@/lib/rate-limit'
import { NextRequest, NextResponse } from 'next/server'

export async function middleware(request: NextRequest) {
  // Only rate limit API routes
  if (request.nextUrl.pathname.startsWith('/api/')) {
    const ip = request.headers.get('x-forwarded-for') ?? 'anonymous'
    const { success } = await ratelimit.limit(ip)

    if (!success) {
      return NextResponse.json({ error: 'Too Many Requests' }, { status: 429 })
    }
  }
}

export const config = {
  matcher: '/api/:path*',
}

Recommended Limits

Endpoint Type	Limit	Window
Login/Register	5 requests	1 minute
Password Reset	3 requests	5 minutes
General API	30 requests	10 seconds
File Upload	5 requests	1 minute

Alternative

Vercel Edge Config - Simpler but less flexible. Built into Vercel, no external service needed.