Debugging with IntelliJ Debug MCP

This skill guides you through debugging applications via the IntelliJ Debug MCP server. The MCP server runs inside IntelliJ IDEA and gives you programmatic control over the debugger.

SAFETY RULES — Read These First

These rules prevent you from hanging indefinitely or losing debugging context. They exist because the debugged application can be suspended on a breakpoint at any time, which means it stops responding to all requests.

The Suspended-Process Trap

When the app hits a breakpoint, its threads freeze. Any HTTP request, curl call, or network interaction you make to that app will hang forever — the app can't respond until you resume it. This is the single most common mistake.

Rule 1: Always use timeouts when talking to the debugged app. Use --max-time 5 with curl, or set run_in_background: true on Bash tool calls. Do this even if you just checked that the app is running — it could hit a breakpoint between your check and your request.

Rule 2: Check suspension status before network calls. Call list_debug_sessions and look at isSuspended. If the app is suspended, either resume it first or accept your request will block.