Vercel Edge Middleware Rate Limit

Vercel Edge Middleware Rate Limit is a boilerplate template from Vercel that adds rate limiting to any frontend application using Vercel KV and Vercel Edge Middleware, without tying you to a specific framework.

What is Vercel Edge Middleware Rate Limit?

Vercel Edge Middleware Rate Limit is a framework-agnostic template that shows how to enforce rate limits by intercepting requests at the edge before they reach your backend. It accepts HTTP requests to any route in your application and, using Vercel KV as a persistent key-value store, tracks request counts per client. When a client exceeds the configured limit, the middleware responds with a 429 Too Many Requests status, blocking the request while allowing normal traffic to pass.

The template runs on Vercel's edge network, meaning the middleware executes in regions close to the user, reducing added latency. It is published as part of the official Vercel examples repository and is intended as a reference pattern for building robust, scalable applications.

Key Features

• Framework-agnostic design — Works with any frontend framework, including Svelte, Astro, Vue, and plain static sites, because it relies on the standard Web Fetch API via @vercel/edge.
• Vercel KV integration — Uses Vercel KV, a durable key-value store, to persist request counters across edge regions, so rate limits are consistent globally.
• Edge execution — Middleware runs on Vercel's edge network before requests reach your origin, so rate limiting adds minimal overhead and scales automatically.
• One-click deploy — A Deploy with Vercel button clones the repository and provisions a Vercel KV store automatically, reducing setup to a single click.
• Next.js guidance — The template notes that Next.js users can use the built-in middleware support instead of @vercel/edge, and points to a dedicated Next.js example.
• Configurable limits — Rate limit thresholds are defined in code, so you can set different limits per route or client type without additional infrastructure.

Who is this for?

• Vercel developers — Developers deploying any app on Vercel who want to protect APIs, login endpoints, or high-traffic pages from abuse and scraping.
• Non-Next.js users — Teams using frameworks like Svelte, Astro, or plain HTML that don't have built-in middleware support but still need edge rate limiting.
• API providers — Developers building public APIs who need a simple, serverless-friendly rate limiter that works across regions without managing Redis or other infrastructure.

What can you do with it?

• Rate limit public APIs: Apply per-IP or per-API-key limits to prevent one client from consuming all your server resources.
• Protect auth endpoints: Throttle login and signup requests to reduce brute-force credential stuffing attempts.
• Guard scraping-prone pages: Limit how many times a single IP can fetch pages in a time window to reduce content scraping.

How does it work?

The middleware function runs on every request, reads a client identifier from the request (such as an IP address or API key), and checks the current count stored in Vercel KV. If the count is below the limit, it increments the counter and allows the request through; if the limit is already reached, it returns a 429 response. The counter storage and increments happen atomically in Vercel KV, ensuring accuracy across concurrent requests.

FAQ

Does this work with Next.js?

Yes, but Vercel specifically notes that Next.js users should use the built-in middleware support rather than @vercel/edge. The template references a separate Next.js example for that path.

What store does it use?

It uses Vercel KV, a key-value database offered by Vercel, which is automatically provisioned when you deploy with the template.

Where does the rate limiting happen?

It happens in Vercel Edge Middleware, which runs on Vercel's edge network, so requests are limited before reaching your serverless functions or origin.

How do I change the rate limit?

Rate limit values are set in the code of the middleware function. You can adjust the maximum number of requests and the time window directly to suit your application.