DebugMCP: give your AI agent a real debugger

Your AI coding agent can scaffold a function, write tests, and refactor a class — but the moment a bug slips through to runtime, it reverts to reading stack traces and guessing. It cannot set a breakpoint. It cannot step through execution. It cannot inspect local variables while the code is actually running. Every debug cycle becomes a loop of "edit, run, read logs, guess again" — with the AI doing the guessing, not the debugging.

DebugMCP v1.1.4 closes that gap. It is a VS Code extension from Microsoft DevLabs that runs an MCP (Model Context Protocol) server inside the IDE, giving any compatible AI assistant full, programmatic access to the VS Code debugger. 1

What DebugMCP does

DebugMCP exposes 13 MCP tools that map directly to debugger actions your AI can now call autonomously: start_debugging, add_breakpoint, step_over, step_into, step_out, continue_execution, get_variables_values, evaluate_expression, and more. 1

The extension supports 9 languages — Python, JavaScript/TypeScript, Java, C#/.NET, C/C++, Go, Rust, PHP, and Ruby — each backed by the corresponding VS Code language extension and its debug adapter. 1 On the AI side, it auto-detects and registers with 8 assistants: GitHub Copilot, GitHub Copilot CLI, Cline, Cursor, Codex, Windsurf, Roo Code, and Antigravity — and works with any other MCP-compatible assistant. 2

All communication stays on localhost:3001. No code, variable values, or debug data leaves the machine. 2

The architecture is straightforward: the AI sends MCP calls over Streamable HTTP to DebugMCP's local server, which translates them into VS Code's Debug Adapter Protocol (DAP) commands that drive the actual language-specific debugger.

DebugMCP architecture: AI Agent → MCP/Streamable HTTP → DebugMCPServer → DebuggingHandler → VS Code Debug API — *Image from: microsoft/DebugMCP — GitHub*

Getting started: three steps

Step 1 — Install. Run in your terminal:

code --install-extension ozzafar.debugmcpextension

Or search for "DebugMCP" directly on the VS Code Marketplace. The extension activates automatically on install and starts the MCP server.

Step 2 — Register with your AI assistant. DebugMCP scans for installed AI assistants and offers to register itself automatically. Accept the prompt, or open the Command Palette and run DebugMCP: Show Agent Selection Popup to trigger it manually. 2

For GitHub Copilot, the registration adds the following to your VS Code settings.json:

{
  "mcp": {
    "servers": {
      "debugmcp": {
        "type": "http",
        "url": "http://localhost:3001/mcp",
        "description": "DebugMCP - Multi-language debugging support"
      }
    }
  }
}

Step 3 — Enable auto-approval. In your AI assistant's tool settings, enable auto-approval for all DebugMCP tools. Without it, every step_over and get_variables_values call will pause to ask for confirmation, breaking the flow of a multi-step debugging session. 2

No launch.json is required. DebugMCP auto-generates a debug configuration from the file extension of the file you ask the AI to debug.

Demo: AI debugs a Python bug end-to-end

Here is a minimal Python file with a division bug. The function returns 2 when it should return 2.5:

# calculator.py
def divide(a, b):
    result = 0
    result = a // b   # Bug: integer division instead of float
    return result

print(divide(5, 2))   # Expected: 2.5  |  Actual: 2

Ask your AI assistant (Copilot, Cline, Cursor — any of the supported ones): "Debug calculator.py — set a breakpoint at the division line and inspect why divide(5, 2) returns 2 instead of 2.5."

The AI then executes the following sequence via DebugMCP tools:

start_debugging(fileFullPath: "/path/to/calculator.py") — launches a Python debug session via debugpy
add_breakpoint(lineContent: "result = a // b") — sets the breakpoint by matching the line text 1
continue_execution() — runs the program until the breakpoint is hit
get_variables_values(scope: "local") — reads the local scope: a=5, b=2, result=0
evaluate_expression(expression: "a / b") — evaluates true float division: returns 2.5
Reports: "// performs integer division; change it to / to get the float result."

No log-reading, no guessing.

DebugMCP animated demo — AI assistant setting breakpoints, stepping through code, and inspecting variables — *Image from: microsoft/DebugMCP — GitHub*

The prerequisite for Python is the Python extension (ms-python.python) — DebugMCP uses VS Code's built-in debugpy adapter, so no separate debugger setup is needed.

Limitations worth knowing before you ship it

DebugMCP is production-ready for most use cases but has a few active bugs as of v1.1.4:

step_into silently degrades to step_over (Issue #71, opened May 10, 2026): after any step-triggered pause, calling step_into on a method call behaves identically to step_over. The failure is silent — no error, no warning. 3 Workaround: call get_stack_trace between every step.
WSL / Linux C/C++ debugging breaks (Issue #70, May 9, 2026): DebugMCP infers a Windows-style .exe target and ignores the program field in an existing launch.json. Manual F5 still works. 4
One debug session at a time: no multi-session support. Running two Claude Code instances (VS Code extension + desktop CLI) against the same DebugMCP server corrupts the server state and requires a window reload. 5
VS Code only: DebugMCP cannot run as a standalone MCP server outside of VS Code. 5

Install and community reception

Marketplace: ozzafar.debugmcpextension 1
CLI: code --install-extension ozzafar.debugmcpextension
License: MIT
Requirements: VS Code 1.104.0+; Windows, macOS, or Linux 1

The GitHub repository has 349 stars and 30 forks as of May 17, 2026 — the highest community signal among the VS Code plugins scanned this week. 2 Gerald Versluis, a Microsoft software engineer working on .NET MAUI and GitHub Copilot, called it out publicly in January 2026:

Loading content card…

That tweet drew 245 likes, 46 retweets, and 18,463 views. 6

References

1
DebugMCP — VS Code Marketplace
marketplace.visualstudio.com
2
microsoft/DebugMCP — GitHub
github.com
3
Issue #71 — step_into silently degrades to step_over
github.com
4
Issue #70 — WSL .exe inference bug
github.com
5
Issue #31 — Standalone MCP Service
github.com
6
Gerald Versluis tweet about DebugMCP
x.com

DebugMCP: give your AI agent a real debugger

What DebugMCP does

All communication stays on localhost:3001. No code, variable values, or debug data leaves the machine. 2

Getting started: three steps

Step 1 — Install. Run in your terminal:

code --install-extension ozzafar.debugmcpextension

Or search for "DebugMCP" directly on the VS Code Marketplace. The extension activates automatically on install and starts the MCP server.

For GitHub Copilot, the registration adds the following to your VS Code settings.json:

{
  "mcp": {
    "servers": {
      "debugmcp": {
        "type": "http",
        "url": "http://localhost:3001/mcp",
        "description": "DebugMCP - Multi-language debugging support"
      }
    }
  }
}

No launch.json is required. DebugMCP auto-generates a debug configuration from the file extension of the file you ask the AI to debug.

Demo: AI debugs a Python bug end-to-end

Here is a minimal Python file with a division bug. The function returns 2 when it should return 2.5:

# calculator.py
def divide(a, b):
    result = 0
    result = a // b   # Bug: integer division instead of float
    return result

print(divide(5, 2))   # Expected: 2.5  |  Actual: 2

The AI then executes the following sequence via DebugMCP tools:

start_debugging(fileFullPath: "/path/to/calculator.py") — launches a Python debug session via debugpy
add_breakpoint(lineContent: "result = a // b") — sets the breakpoint by matching the line text 1
continue_execution() — runs the program until the breakpoint is hit
get_variables_values(scope: "local") — reads the local scope: a=5, b=2, result=0
evaluate_expression(expression: "a / b") — evaluates true float division: returns 2.5
Reports: "// performs integer division; change it to / to get the float result."

No log-reading, no guessing.

The prerequisite for Python is the Python extension (ms-python.python) — DebugMCP uses VS Code's built-in debugpy adapter, so no separate debugger setup is needed.

Limitations worth knowing before you ship it

DebugMCP is production-ready for most use cases but has a few active bugs as of v1.1.4:

step_into silently degrades to step_over (Issue #71, opened May 10, 2026): after any step-triggered pause, calling step_into on a method call behaves identically to step_over. The failure is silent — no error, no warning. 3 Workaround: call get_stack_trace between every step.
WSL / Linux C/C++ debugging breaks (Issue #70, May 9, 2026): DebugMCP infers a Windows-style .exe target and ignores the program field in an existing launch.json. Manual F5 still works. 4
One debug session at a time: no multi-session support. Running two Claude Code instances (VS Code extension + desktop CLI) against the same DebugMCP server corrupts the server state and requires a window reload. 5
VS Code only: DebugMCP cannot run as a standalone MCP server outside of VS Code. 5

Install and community reception

Marketplace: ozzafar.debugmcpextension 1
CLI: code --install-extension ozzafar.debugmcpextension
License: MIT
Requirements: VS Code 1.104.0+; Windows, macOS, or Linux 1

Gerald Versluis @jfversluis·39w

Controlling your debug sessions through Copilot? Absolutely now you can! Check out this MCP for @code

View on X

Loading content card…

That tweet drew 245 likes, 46 retweets, and 18,463 views. 6

References

1
DebugMCP — VS Code Marketplace
marketplace.visualstudio.com
2
microsoft/DebugMCP — GitHub
github.com
3
Issue #71 — step_into silently degrades to step_over
github.com
4
Issue #70 — WSL .exe inference bug
github.com
5
Issue #31 — Standalone MCP Service
github.com
6
Gerald Versluis tweet about DebugMCP
x.com

DebugMCP: Give Your AI Agent a Real Debugger in VS Code

DebugMCP: give your AI agent a real debugger

What DebugMCP does

Getting started: three steps

Demo: AI debugs a Python bug end-to-end

Limitations worth knowing before you ship it

Install and community reception

References

Related content

DebugMCP: Give Your AI Agent a Real Debugger in VS Code

DebugMCP: give your AI agent a real debugger

What DebugMCP does

Getting started: three steps

Demo: AI debugs a Python bug end-to-end

Limitations worth knowing before you ship it

Install and community reception

References

Related content