Rate Limiting Strategies in .NET

Rate Limiting Strategies in .NET


Managing traffic effectively is crucial to maintain service quality and prevent abuse.

Rate limiting is a powerful technique that allows you to control the flow of incoming requests to your API. In this blog post, we’ll explore rate-limiting strategies in .NET and provide C# examples to help you implement them effectively.

Understanding Rate Limiting Strategies

Rate limiting involves limiting the number of requests a client can make to your API within a specific time frame. The choice of rate-limiting strategy depends on your application’s requirements and goals. Here are some common rate-limiting strategies:

  1. IP-Based Rate Limiting: Limit requests based on the client’s IP address. This strategy prevents a single IP from overwhelming your API.
  2. Client-Based Rate Limiting: Rate limit requests based on the client’s identity or API key. This approach is effective for identifying and controlling individual clients.
  3. Endpoint-Based Rate Limiting: Apply rate limits to specific API endpoints. You can restrict access to high-traffic endpoints to ensure fair resource allocation.
  4. Token Bucket Algorithm: Implement a token bucket algorithm that replenishes tokens at a fixed rate. Clients can only make requests when they have tokens available.

Now, let’s dive into implementing these rate-limiting strategies in a .NET application using C# examples.

Implementing Rate Limiting in .NET

We’ll use the AspNetCoreRateLimit package to implement rate limiting in a .NET Core application. Here’s how to set it up:

Step 1: Install the AspNetCoreRateLimit Package

Install the AspNetCoreRateLimit package using the following command:

dotnet add package AspNetCoreRateLimit

Step 2: Configure Rate Limiting

In your Startup.cs file, configure rate limiting services and middleware:

// Add the required services in ConfigureServices method
public void ConfigureServices(IServiceCollection services)
    // Add other services...

// Configure the middleware in Configure method
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    // Other middleware configurations...

Step 3: Apply Rate Limiting Strategies

Apply rate-limiting strategies to your API endpoints using the [RateLimit] attribute. Here’s an example of IP-based rate limiting:

public IActionResult IpLimitedEndpoint()
    // Your code here

For client-based rate limiting, you can use the [ClientRateLimit] attribute:

public IActionResult ClientLimitedEndpoint()
    // Your code here

And for endpoint-based rate limiting:

public IActionResult EndpointLimitedEndpoint()
    // Your code here

Customize Rate Limiting Rules

You can customize rate-limiting rules in the appsettings.json file to tailor them to your application’s needs. Specify the rules for IP, client, and endpoint-based rate limiting along with their respective limits and periods.

"RateLimiting": {
  "IpRules": [
      "Endpoint": "*",
      "Period": "1m",
      "Limit": 60
  "ClientRules": [
      "Endpoint": "*",
      "Period": "1h",
      "Limit": 1000
  "EndpointRules": [
      "Endpoint": "api/endpoint-limited-endpoint",
      "Period": "1d",
      "Limit": 500


Rate limiting is critical to managing API traffic effectively in .NET applications.

By implementing rate-limiting strategies such as IP-based, client-based, and endpoint-based rate limiting using the AspNetCoreRateLimit package, you can ensure fair resource allocation, prevent abuse, and maintain the reliability of your API. Use the provided C# examples as a starting point to incorporate rate limiting into your .NET application and enhance its overall performance and security.


Hi, my name is Stephen Finchett. I have been a software engineer for over 30 years and worked on complex, business critical, multi-user systems for all of my career. For the last 15 years, I have been concentrating on web based solutions using the Microsoft Stack including ASP.Net, C#, TypeScript, SQL Server and running everything at scale within Kubernetes.