How to Debug HTTP Traffic with the Network Inspector

ASD includes a built-in network inspector powered by mitmproxy. It runs as a proxy that captures and displays HTTP/HTTPS traffic in a web UI. Useful for debugging API calls, inspecting request/response headers, and understanding what your application sends over the network.

Status: Alpha. The network inspector currently runs as a standalone proxy. Automatic traffic routing via Caddy is planned for a future release.

What you get

• HTTP/HTTPS traffic capture and display
• Web-based UI for browsing requests
• Request/response body inspection
• Filter and search traffic

Prerequisites

• ASD CLI installed (asd init to set up your workspace)
• The mitmproxy binary (auto-downloaded during asd init)

Step 1: Start the inspector

asd inspect start

To see the status and access the web UI:

asd inspect

Step 2: Configure your app to use the proxy

Since the inspector runs as a standalone proxy, you need to configure your application to route traffic through it. The default proxy port is 8080.

Environment variable (works for most HTTP clients):

export HTTP_PROXY=http://localhost:8080
export HTTPS_PROXY=http://localhost:8080

Node.js with fetch:

HTTP_PROXY=http://localhost:8080 node app.js

curl:

curl --proxy http://localhost:8080 https://api.example.com/endpoint

Step 3: View traffic in the web UI

Open the mitmproxy web interface in your browser. The URL is shown when you run asd inspect. You'll see all HTTP requests flowing through the proxy in real time.

Configuration

Current limitations

The network inspector is in alpha. These features are not yet available:

• Automatic traffic routing via Caddy
• Per-service inspection toggles in TUI
• Transparent proxy mode
• TLS certificate auto-installation

Stopping the inspector

asd inspect stop

What's next

• Web Terminal with ttyd — shell access for debugging
• Database GUI with DbGate — inspect your data
• Add Basic Authentication — protect services with passwords