Create a new debugging session. Provide host and port to attach to a running process; omit them for launch mode

List all supported debugging languages with metadata

List all active debugging sessions

Set a breakpoint. Setting breakpoints on non-executable lines (structural, declarative) may lead to unexpected behavior

Start debugging a script

Attach to a running process for debugging

Detach from the debugged process without terminating it

Close a debugging session

Step over

Step into

Step out

Continue execution

Pause a running program

List all threads in the debugged process

Get variables (scope is variablesReference: number)

Get local variables for the current stack frame. This is a convenience tool that returns just the local variables without needing to traverse stack->scopes->variables manually

Get stack trace

Get scopes for a stack frame

Evaluate expression in the current debug context. Expressions can read and modify program state

Get source context around a specific line in a file

Hot-swap changed Java classes into a running JVM. Scans a classes directory for .class files modified after sinceTimestamp, matches them against loaded classes in the target JVM, and redefines them using JDI. Returns which classes were redefined and the newest file timestamp (pass as sinceTimestamp on next call for incremental updates). Only works with Java debug sessions.