🦉 Exploring the Duolingo app internal API

How to Explore the Duolingo App Internal API

Duolingo is a popular language-learning app, and in this tutorial, we will explore its internal API using an emulator and a proxy tool. By following these steps, you can gain insights into how the app functions behind the scenes.

Tools Required:

1. Duolingo Android app emulator
2. Proximen (proxy tool)
3. Loadmill (API analysis tool)

Steps:

1. Download and Install Tools:

   • Download and install an Android emulator on your laptop.
   • Install Proximen, a proxy tool that allows you to intercept and analyze network requests.

2. Load Duolingo App on Emulator:

   • Load the Duolingo Android app onto the emulator on your laptop.

3. Set Up Proximen:

   • Configure Proximen to intercept network requests from the Duolingo app.

4. Analyze Network Requests:

   • Use Proximen to analyze the network requests made by the Duolingo app.
   • Look at the different domains and hosts being used, such as Facebook Graph and Android API.

5. Analyze API Requests with Loadmill:

   • Load some of the requests into Loadmill for further analysis.
   • Analyze the login flow, including sending the username and password and receiving a JWT token for authentication.

6. Explore API Endpoints:

   • Look into different API endpoints like listing items on the store and starting a lesson on Duolingo.
   • Examine the structure of the API responses, including questions, prompts, choices, and correct answers.

7. Discover Security Measures:

   • Explore how Duolingo protects features like streak freeze through its API.
   • Learn about their approach, such as using a polling mechanism and managing responses based on file existence.

8. Understand API Structure:

   • Delve into the organization of the API messages and sessions within the Duolingo app.
   • Appreciate the well-organized JSON keys that provide clear explanations of the data.

9. Explore Further Opportunities:

   • Consider exploring APIs of other apps for analysis and insights.
   • Connect with the tutorial creator on Twitter for suggestions or requests for analyzing APIs of other apps.

10. Conclusion:

    • By following these steps, you can gain a deeper understanding of the Duolingo app's internal API and explore potential insights for other apps as well.

This tutorial provides a comprehensive guide to exploring the Duolingo app's internal API and understanding its functionality behind the scenes.