Teaching a New Dog Old Tricks: Give the Agent a Debugger

When code misbehaves, coding agents often fall back on an old habit. They add print statements. The method works. It also changes the program before the agent understands the problem.

The debugger provides a cleaner way to find the evidence. Logpoints inspect application state while the program keeps running. They can write custom messages without changing the source. You can even place them inside compiled third-party libraries. Every output line links back to the code that produced it. This includes logpoints and regular loggers as well as print statements.

IntelliJ IDEA makes its debugger tools available to coding agents. The debugger skill covers dozens of tools and settings. Few developers keep all of them in their heads. The complete playbook fits into the agent's context.

The agent combines that debugger knowledge with its understanding of the project code. It can choose useful locations for breakpoints and logpoints. It can start a debug run configuration and read actual values. As the evidence develops, it can move its observation points. The source stays untouched.

What attendees will learn:

- How Logpoints capture runtime state without suspending the program or modifying its source
- How to investigate behavior inside compiled third-party libraries
- How navigable debugger output connects runtime observations to their origin in code
- How an agent combines code context with debugger knowledge to place useful breakpoints and logpoints