Arcjet rate limiting allows you to define rules which limit the number of
requests a client can make over a period of time.
What is Arcjet?Arcjet helps developers protect their apps
in just a few lines of code. Bot detection. Rate limiting. Email validation. Attack protection. Data redaction. A developer-first approach to security.
Video quick start
Quick start
This guide will show you how to add a simple rate limit to your app.
1. Install Arcjet
In your project root, run the following command to install the SDK:
2. Set your key
Create a free Arcjet account then follow the
instructions to add a site and get a key. Add it to a .env.local file in your
project root.
3. Add a rate limit to a route
The example below applies a token bucket rate limit rule to a route where we
identify the user based on their ID e.g. if they are logged in. The bucket is
configured with a maximum capacity of 10 tokens and refills by 5 tokens every
10 seconds. Each request consumes 5 tokens.
Create a new API route at /src/routes/api/arcjet/+server.ts:
Create a new API route at /src/routes/api/arcjet/+server.js:
Create a new API route at /pages/api/arcjet.js:
Create a new API route at /app/api/arcjet/route.ts:
Create a new API route at /app/api/arcjet/route.js:
Create a new API route at /pages/api/arcjet.ts:
4. Start app
Start your app and load http://localhost:5173/api/arcjet. Refresh the page and
you will see the rate limit in action. The requests will also show up in the
Arcjet dashboard.
4. Start server
Then make some requests to hit the rate limit:
4. Start app
Start your Next.js app:
Then load http://localhost:3000/api/arcjet. Refresh the page and you will see
the rate limit in action. The requests will also show up in the Arcjet
dashboard.
4. Start server
Then make some requests to hit the rate limit:
FAQs
Do I need to run any infrastructure e.g. Redis?
No, Arcjet handles all the infrastructure for you so you don't need to
worry about deploying global Redis clusters, designing data structures to
track rate limits, or keeping security detection rules up to date.
What is the performance overhead?
Arcjet SDK tries to do as much as possible asynchronously and locally to
minimize latency for each request. Where decisions can be made locally or
previous decisions are cached in-memory, latency is usually <1ms.
When a call to the Arcjet API is required, such as when tracking a
rate limit in a serverless environment, there is some additional latency
before a decision is made. The Arcjet API has been designed for high
performance and low latency, and is deployed to multiple regions around the
world. The SDK will automatically use the closest region which means the
total overhead is typically no more than 20-30ms, often significantly less.
What happens if Arcjet is unavailable?
Where a decision has been cached locally e.g. blocking a client, Arcjet
will continue to function even if the service is unavailable.
If a call to the Arcjet API is needed and there is a network problem or
Arcjet is unavailable, the default behavior is to fail open and allow
the request. You have control over how to handle errors, including choosing
to fail close if you prefer. See the reference docs for details.
How does Arcjet protect me against DDoS attacks?
Network layer attacks tend to be generic and high volume, so these are
best handled by your hosting platform. Most cloud providers include network
DDoS protection by default.
Arcjet sits closer to your application so it can understand the context.
This is important because some types of traffic may not look like a DDoS
attack, but can still have the same effect. For example, a customer making
too many API requests and affecting other customers, or large numbers of
signups from disposable email addresses.
Network-level DDoS protection tools find it difficult to protect against
this type of traffic because they don't understand the structure of your
application. Arcjet can help you to identify and block this traffic by
integrating with your codebase and understanding the context of the
request e.g. the customer ID or sensitivity of the API route.
Volumetric network attacks are best handled by your hosting provider.
Application level attacks need to be handled by the application. That's
where Arcjet helps.
What next?
Arcjet can be used with specific rules on individual routes or as general
protection on your entire application. You can customize bot protection, rate
limiting for your API and minimize fraudulent registrations with the signup form
protection.