TunnelliJ

A TCP tunnel and network traffic sniffer plugin for JetBrains IntelliJ IDEA.

Note: I wrote this plugin in 2004 and I am quite amazed that after small revamp (thanks Claude Code) it still works fine!

Description

TunnelliJ allows you to monitor and analyze network traffic between client and server applications directly within your IDE. It's useful for debugging web applications, web services, and any TCP-based communication.

Features

• Listen on a configurable local port (default: 4444)
• Forward all traffic to a destination host:port (default: localhost:6060)
• Capture and display both request and response data
• View connection timestamps, data sizes, and duration
• Line wrapping toggle for better readability
• Settings persistence between sessions

Installation

1. Download tunnellij_1.6.jar from the releases or build from source
2. In IntelliJ IDEA: Settings → Plugins → ⚙️ → Install Plugin from Disk...
3. Select the JAR file and restart the IDE

Usage

1. Open the TunnelliJ tool window (bottom panel)
2. Configure source port, destination host, and destination port
3. Click Start to begin capturing traffic
4. Point your client application to the configured source port
5. View captured connections in the list and inspect request/response data

Building from Source

Requires Apache Ant and JDK 17+.

ant jar

The plugin JAR will be created in the build/ directory.

Author

Milan Boruvka

• Email: milan.boruvka@gmail.com
• Website: http://www.boruvka.net

License

Apache License 2.0

Links

• JetBrains Plugin Repository