Django Rest Framework API Throttling Guide

API throttling is essential for protecting your Django Rest Framework (DRF) APIs from abuse. It limits the number of requests a user can make within a specific time frame. This ensures fair usage and prevents server overload.

In this guide, we'll explore how to implement and customize throttling in DRF. We'll also discuss best practices to secure your APIs effectively.

What is API Throttling?

API throttling controls the rate of requests to your API. It prevents users from making too many requests in a short period. This protects your server from being overwhelmed.

Throttling is especially important for public APIs. It ensures that all users have equal access to resources. It also helps prevent malicious attacks like DDoS.

Types of Throttling in Django Rest Framework

DRF provides three types of throttling: AnonRateThrottle, UserRateThrottle, and ScopedRateThrottle. Each serves a different purpose.

AnonRateThrottle limits requests from anonymous users. UserRateThrottle applies to authenticated users. ScopedRateThrottle allows custom throttling for specific views.

How to Implement Throttling in DRF

To enable throttling, add the DEFAULT_THROTTLE_CLASSES and DEFAULT_THROTTLE_RATES settings in your settings.py file. Here's an example:

    REST_FRAMEWORK = {
        'DEFAULT_THROTTLE_CLASSES': [
            'rest_framework.throttling.AnonRateThrottle',
            'rest_framework.throttling.UserRateThrottle'
        ],
        'DEFAULT_THROTTLE_RATES': {
            'anon': '100/day',
            'user': '1000/day'
        }
    }
    

In this example, anonymous users are limited to 100 requests per day. Authenticated users can make up to 1000 requests per day.

Customizing Throttling Rates

You can customize throttling rates for specific views. Use the throttle_scope attribute in your view. Here's an example:

    from rest_framework.throttling import ScopedRateThrottle
    from rest_framework.views import APIView

    class CustomThrottleView(APIView):
        throttle_scope = 'custom'
        throttle_classes = [ScopedRateThrottle]

        def get(self, request):
            return Response("Custom Throttle View")
    

Then, define the rate in settings.py:

    REST_FRAMEWORK = {
        'DEFAULT_THROTTLE_RATES': {
            'custom': '50/hour'
        }
    }
    

This limits the CustomThrottleView to 50 requests per hour.

Handling Throttling Exceptions

When a user exceeds the throttling limit, DRF raises a Throttled exception. You can customize the error message using the throttled method.

    from rest_framework.exceptions import Throttled
    from rest_framework.views import exception_handler

    def custom_exception_handler(exc, context):
        response = exception_handler(exc, context)
        if isinstance(exc, Throttled):
            response.data = {
                'detail': 'Request limit exceeded. Try again later.'
            }
        return response
    

Add this handler to your settings.py:

    REST_FRAMEWORK = {
        'EXCEPTION_HANDLER': 'path.to.custom_exception_handler'
    }
    

Best Practices for API Throttling

1. Use different rates for anonymous and authenticated users. This ensures fair usage.

2. Monitor API usage regularly. Adjust throttling rates based on traffic patterns.

3. Combine throttling with authentication and permissions for better security.

Conclusion

API throttling is a powerful tool to prevent abuse and ensure fair usage. By implementing and customizing throttling in Django Rest Framework, you can protect your APIs effectively.

For more advanced features, explore ViewSets and Routers in DRF. This will help you build scalable and secure APIs.