Super simple API throttling / rate limit framework based on attributes

Install the SharpApiRateLimit package via Nuget:

Install-Package SharpApiRateLimit

Open your Startup.cs and configure your reverse proxy:

public void ConfigureServices(IServiceCollection services) {
    services.AddRateLimit();
    //other
    ...
}

Add your attributes on a controller or action level:

[RateLimitByHeader("X-UserId", "1s", calls: 1)]
public class ValuesController : ControllerBase {

    [HttpGet]
    [RateLimitByHeader("X-UserId", "15s", calls: 2)]
    public ActionResult<IEnumerable<string>> Get() {
        return new string[] { "value1", "value2" };
    }

    [HttpGet("{id}")]
    [RateLimitByHeader("X-UserId", "10m", calls: 100)]
    public ActionResult<string> Get(int id) {
        return "value";
    }

    [HttpPost]
    public void Post([FromBody] string value) {
    }

    [HttpPut("{id}")]
    public void Put(int id, [FromBody] string value) {
    }

    [HttpDelete("{id}")]
    public void Delete(int id) {
    }
}

In the example above, all calls will be rate limited to 1 call per second. Users will be identified using the header 'X-UserId', use the one you need.

The limits for the actions GET:/values/get and GET:/values/get/{id} will be overridden with the local attribute.

• s: seconds. Ex: 1s, 4s
• m: minutes. Ex: 10m, 30m
• h: hours. Ex: 1h, 10h
• d: days. Ex. 1d, 2d

Information about current calls are stored using Asp.Net IMemoryCache. If you want to change that, just create a class that implements IRateLimitStorage and register it with the ServiceLocator.

Ex:

services.AddSingleton<IRateLimitStorage, MyCustomStorage>();

To change the error message, create a class implementing IRateLimitResponseSerializer and register it:

Ex:

services.AddSingleton<IRateLimitResponseSerializer, MyCustomResponseSerializer>();

Enjoy!