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 initto set up your workspace) - The mitmproxy binary (auto-downloaded during
asd init)
Step 1: Start the inspector
asd inspect startTo see the status and access the web UI:
asd inspectStep 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:8080Node.js with fetch:
HTTP_PROXY=http://localhost:8080 node app.jscurl:
curl --proxy http://localhost:8080 https://api.example.com/endpointStep 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
| Variable | Default | Description |
|---|---|---|
ASD_MITMPROXY_PORT | 8080 | Proxy port |
ASD_BASIC_AUTH_PASSWORD | — | Web UI password |
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 stopWhat's next
- Web Terminal with ttyd — shell access for debugging
- Database GUI with DbGate — inspect your data
- Add Basic Authentication — protect services with passwords
Kelvin Wuite
Kelvin Wuite is the founder of Accelerated Software Development B.V. With over eighteen years of development experience, he has witnessed the same patterns repeat across every software team: endless documentation, manual preparation, environment mismatches, and fragmented collaboration. His drive is to remove these barriers, enabling engineers to work together in unified environments with shorter feedback loops and hands-on collaboration. Since 2015 he has been refining these ideas, leading to ASD — a platform designed to create a faster, more integrated way for development teams to collaborate in an age where AI is thriving.
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