Using Fiddler and JMeter for Mobile App API Test Automation (iOS)

The article outlines a step‑by‑step process for creating automated API test cases for an iOS mobile application. First, it describes configuring Fiddler to capture HTTPS traffic by enabling HTTPS decryption, setting the proxy port (default 8888), and installing the Fiddler Root certificate on the iPhone.

Next, it details connecting the phone to the same Wi‑Fi network as the computer, configuring the Wi‑Fi proxy with the computer’s IP address and port, and trusting the installed certificate in iOS settings. After these steps, the app’s login request can be captured by Fiddler.

The guide then switches to JMeter, showing how to add a Thread Group, HTTP Header Manager, and HTTP Request defaults. It demonstrates importing the captured request parameters (method, URL, headers, body) into JMeter, adding a JSON Extractor to retrieve the authentication token from the login response, and using a Debug Sampler to verify the token extraction.

Finally, it explains how to create subsequent API requests (e.g., a query interface) by reusing the token, adding response assertions to verify successful calls, and debugging the results to ensure they match the Fiddler capture. The article concludes with a call for readers to follow and share the content.