dap-cli-debugging

name	dap-cli-debugging
description	Control the VS Code Debugger (DAP) via CLI commands using mcp-debug-tools. Use when debugging, setting breakpoints, stepping through code, or inspecting variables.

AI Agent Skill: VS Code DAP Debugger Control via CLI

Objective

You (the AI Agent) can directly control the VS Code Debugger (DAP) via terminal CLI commands. No stdio connection needed — use one-off CLI commands to control the full debug lifecycle.

CLI Interface

All commands use: npx @uhd_kr/mcp-debug-tools <command> [args]

Local Path Fallback (When npx is unavailable)

If npx is unavailable (e.g., offline, network restrictions), you can run the CLI directly from the VS Code extension's install directory.

macOS / Linux:

node ~/.vscode/extensions/uhd.mcp-debug-tools-*/out/cli.js <command> [args]

Windows (PowerShell):

node "$env:USERPROFILE\.vscode\extensions\uhd.mcp-debug-tools-*\out\cli.js" <command> [args]

Windows (CMD):

node "%USERPROFILE%\.vscode\extensions\uhd.mcp-debug-tools-*\out\cli.js" <command> [args]

Tip: If you installed mcp-debug-tools globally via npm install -g @uhd_kr/mcp-debug-tools, you can simply run mcp-debug-tools <command> directly without npx.

Key Rules:

• stdout = pure JSON result. Always parse stdout only.
• stderr = connection logs. Ignore stderr.
• On error, read the JSON error message, correct arguments, and retry.

Commands

Command	Usage
list	npx mcp-debug-tools list — Discover all available tools and their input schemas
call	npx mcp-debug-tools call <toolName> [jsonArgs] — Execute a specific tool
read	npx mcp-debug-tools read <resourceUri> — Read a debugger state resource

Available Tools — Quick Reference

Session & Config Management

Tool	Params	Description
get-active-session	—	Check if debugger is running, get session info
get-debug-state	—	Get full debug state: session + all breakpoints
list-debug-configs	—	List all configurations from launch.json
select-debug-config	configName	Select a specific debug configuration by name
start-debug	config (name from launch.json)	Start a debug session
stop-debug	—	Stop the active debug session
get-workspace-info	—	Get current workspace information
list-vscode-instances	—	List all active VS Code instances
select-vscode-instance	port?, workspace?	Connect to a specific VS Code instance

Breakpoint Management

Tool	Params	Description
add-breakpoint	file, line, condition?, hitCondition?, logMessage?	Add a single breakpoint
add-breakpoints	breakpoints[] (array of above)	Add multiple breakpoints at once
remove-breakpoint	file, line	Remove a breakpoint at specific location
clear-breakpoints	files?[]	Remove all breakpoints (or from specific files)
list-breakpoints	—	List all breakpoints (basic)
get-breakpoints	—	Get detailed breakpoint info including conditions

Execution Control

Tool	Params	Description
continue	—	Resume execution
step-over	—	Step over current line
step-into	—	Step into function call
step-out	—	Step out of current function
pause	—	Pause running execution

State Inspection

Tool	Params	Description
get-call-stack	threadId?, startFrame?, levels?	Get call stack frames
get-active-stack-item	—	Get the currently active stack frame
get-variables-scope	frameId?, scopeName?	Get all variables in scope
inspect-variable	variableName	Get detailed info about a specific variable
evaluate-expression	expression	Evaluate an expression in debug context
get-thread-list	—	List all threads
get-exception-info	limit?, includeStackTrace?	Get recent exception details
get-debug-console	limit?, filter?	Retrieve debug console output
get-dap-log	—	Get raw DAP protocol messages

CLI Examples

# Check debugger status
npx mcp-debug-tools call get-active-session

# Set a conditional breakpoint
npx mcp-debug-tools call add-breakpoint '{"file": "src/app.ts", "line": 15, "condition": "x > 10"}'

# Set multiple breakpoints at once
npx mcp-debug-tools call add-breakpoints '{"breakpoints": [{"file": "src/app.ts", "line": 10}, {"file": "src/app.ts", "line": 20}]}'

# Start debugging with a named config
npx mcp-debug-tools call start-debug '{"config": "Launch Program"}'

# Step and inspect
npx mcp-debug-tools call step-over
npx mcp-debug-tools call get-variables-scope
npx mcp-debug-tools call inspect-variable '{"variableName": "result"}'

# Evaluate an expression at current breakpoint
npx mcp-debug-tools call evaluate-expression '{"expression": "arr.length"}'

# Read resources directly
npx mcp-debug-tools read "dap://log"

Standard Debugging Workflow

1. Check Status → get-active-session
2. List Configs → list-debug-configs (find the right launch config)
3. Set Breakpoints → add-breakpoint or add-breakpoints
4. Start Debug → start-debug with the config name
5. Analyze State → get-call-stack + get-variables-scope
6. Inspect Details → inspect-variable or evaluate-expression
7. Step Through → step-over / step-into / step-out, repeat 5-6
8. Fix Code → Edit source, then restart debugger to verify