Rate Limiting with Hooks
Implement request rate limiting in the handle() hook to protect API routes.
Rate Limiting with Hooks is a free Sveltejs Academy lesson on CoddyKit — lesson 4 of 4. You can read the complete lesson below for free — then practise it hands-on in the browser with a built-in code editor and a 24/7 AI tutor. It is part of the Sveltejs Academy learning path, one of 4 lessons in the course, and your progress syncs across the web and the CoddyKit app.
Why Rate Limit
Protect APIs from abuse: brute-force logins, scraping, and accidental overload.
Implement in handle
Track requests per IP in memory or Redis and reject when over limit.
const counts = new Map();
export async function handle({ event, resolve }) {
const ip = event.getClientAddress();
const n = (counts.get(ip) || 0) + 1;
counts.set(ip, n);
if (n > 100) return new Response("Too many", { status: 429 });
return resolve(event);
}Sliding Window
Use a sliding window algorithm for fair rate limiting.
Redis-Backed
For multi-instance deployments, store counts in Redis or a similar shared store.
Per-Route Limits
Apply different limits to different routes (e.g., stricter on /login).
429 Status
Return HTTP 429 with a Retry-After header so clients know when to retry.
Header Hints
Set X-RateLimit-* headers to inform clients of their quota.
Per-User Limits
For authenticated users, key the limit by user ID for fairness.
Libraries
Use existing libraries (sveltekit-rate-limiter) instead of rolling your own.
Logging
Log throttled requests to detect attacks and tune limits.
CDN Layer
Use Cloudflare or similar to apply baseline rate limits at the edge before requests hit your app.
Quick Check
What status code do you return when rate limit is exceeded?
Recap
Implement rate limiting in the handle hook. Use Redis for multi-instance setups; return 429 with Retry-After.
Frequently asked questions
Is the “Rate Limiting with Hooks” lesson free?
Yes — the full text of “Rate Limiting with Hooks” is free to read here on the web, and the Sveltejs Academy course includes 4 lessons in total. To practise it interactively (a built-in code editor and a 24/7 AI tutor) and unlock the rest of the Sveltejs Academy course, upgrade to CoddyKit PRO.
What will I learn in “Rate Limiting with Hooks”?
Implement request rate limiting in the handle() hook to protect API routes. You practise Sveltejs Academy with hands-on code you run directly in the browser, and a 24/7 AI tutor answers your questions as you work through the lesson.
Do I need any experience to start Sveltejs Academy?
No prior experience is required. Sveltejs Academy on CoddyKit is structured for beginners through advanced learners; this is — lesson 4 of 4, so you can start here or from the beginning and move at your own pace.
How long does the “Rate Limiting with Hooks” lesson take?
Most CoddyKit lessons take about 5–10 minutes. Each one is bite-sized and interactive, so you make steady progress and pick up exactly where you left off across the web and the app.
Can I write and run code in this Sveltejs Academy lesson?
Yes. Every Sveltejs Academy lesson includes a built-in code editor, so you write and run real code right in your browser and get instant AI feedback — no local setup required.