Testing how your React/Vue/Angular app handles server failures is tough. Do your loading spinners actually show up? Does the "Retry" button appear when the API returns a 503?

In this guide, we will configure FoxyProxy to route only your browser traffic through Debuggo Chaos Proxy, leaving the rest of your Mac's internet connection untouched.

Looking for a desktop alternative? Check out our detailed comparison of Proxyman vs Charles vs Debuggo to see which tool fits your workflow best in 2025.

Step 1: Configure Chaos Rules

Create a rule in Debuggo to target the API you want to test. We will use httpbin.org as an example.

Rule Configuration:

URL Pattern (Regex)httpbin.org
Delay10 seconds
Failure Rate1 (100% error rate)
Error CodePro503 Service Unavailable

Step 2: Trust the Certificate (MacOS)

Since we are intercepting HTTPS traffic, you need to install the CA certificate.

Start the session in Debuggo dashboard.
Download mitmproxy-ca-cert.pem.
Double-click to install it into Keychain Access (System).
Right-click the certificate → Get Info → Trust → "Always Trust".

Step 3: Setup FoxyProxy

Install the FoxyProxy extension for Chrome or Firefox. Click "Add New Proxy" and use these credentials:

Proxy Host

chaos-proxy.debuggo.app

Port

11997

Username

chaos

Password

qjz7twjqzbs8w7uv

Step 4: Verify the Chaos

Enable the proxy in FoxyProxy and navigate to:
https://httpbin.org/get

⚠️ Pro Tip: If the page loads normally on the first try, refresh it! Browsers sometimes cache connections or take a few seconds to apply new proxy authentication settings.

What you will see:

The browser tab will "spin" for exactly 10 seconds (simulating your delay).
After the delay, you will either see the JSON response OR a 503 Service Unavailable page injected by Debuggo.

Pro Tip: Catch race conditions with latency. Read our guide: The "Spinner of Death".

Automate with AI

Still testing manually?

Automate network resilience testing with Debuggo AI. Generate UI and API tests in minutes.

Learn more on debuggo.app →