mcp-dap-server

MCP DAP Server

A Model Context Protocol (MCP) server that provides debugging capabilities through the Debug Adapter Protocol (DAP). This server enables AI assistants and other MCP clients to interact with debuggers for various programming languages.

Overview

The MCP DAP Server acts as a bridge between MCP clients and DAP-compatible debuggers, allowing programmatic control of debugging sessions. It provides a comprehensive set of debugging tools that can be used to:

• Start and stop debugging sessions
• Set breakpoints (line-based and function-based)
• Control program execution (continue, step in/out/over, pause)
• Inspect program state (threads, stack traces, variables, scopes)
• Evaluate expressions
• Attach to running processes
• Handle exceptions

Demos

• Basic demo with multiple prompts
• Autonomous agentic debugging pt.1
• Autonomous agentic debugging pt.2

Features

Core Debugging Operations

• Session Management: Start, stop, restart, and terminate debugging sessions
• Breakpoint Management: Set line and function breakpoints
• Execution Control: Continue, pause, step operations (in/out/next)
• State Inspection: View threads, stack traces, scopes, and variables
• Expression Evaluation: Evaluate expressions in the current debugging context
• Variable Modification: Change variable values during debugging

Advanced Features

• Process Attachment: Attach to already running processes
• Module Information: List loaded modules
• Source Information: View loaded source files
• Disassembly: View disassembled code
• Exception Handling: Get information about exceptions

Installation

Prerequisites

• Go 1.24.4 or later
• A DAP-compatible debugger for your target language

Building from Source

git clone https://github.com/go-delve/mcp-dap-server
cd mcp-dap-server
go build -o bin/mcp-dap-server

Usage

Starting the Server

The server listens on port 8080 by default:

./bin/mcp-dap-server

Connecting via MCP

Configure your MCP client to connect to the server at http://localhost:8080 using the SSE (Server-Sent Events) transport.

Example MCP Client Configuration

This configuration should work (or serve as a starting point) for Agents such as (Gemini CLI)[https://developers.google.com/gemini-code-assist/docs/use-agentic-chat-pair-programmer#configure-mcp-servers].

{
  "mcpServers": {
    "dap-debugger": {
      "command": "mcp-dap-server",
      "args": [],
      "env": {}
    }
  }
}

Example configuration using Claude Code

Claude Code

claude mcp add --transport sse mcp-dap-server http://localhost:8080

Available Tools

Session Management

start_debugger

Starts a new debugging session.

• Parameters:
  • port (number): The port number for the DAP server

stop_debugger

Stops the current debugging session.

restart_debugger

Restarts the current debugging session.

terminate_debugger

Terminates the debugger and the debuggee process.

Program Control

debug_program

Launches a program in debug mode.

• Parameters:
  • path (string): Path to the program to debug

exec_program

Executes a program without debugging.

• Parameters:
  • path (string): Path to the program to execute

attach_debugger

Attaches to a running process.

• Parameters:
  • mode (string): Attachment mode
  • processId (number, optional): Process ID to attach to

Breakpoints

set_breakpoints

Sets line breakpoints in a file.

• Parameters:
  • file (string): Source file path
  • lines (array): Line numbers for breakpoints

set_function_breakpoints

Sets function breakpoints.

• Parameters:
  • functions (array): Function names

Execution Control

continue

Continues program execution.

• Parameters:
  • threadId (number, optional): Thread ID to continue

next

Steps over the current line.

• Parameters:
  • threadId (number): Thread ID

step_in

Steps into function calls.

• Parameters:
  • threadId (number): Thread ID

step_out

Steps out of the current function.

• Parameters:
  • threadId (number): Thread ID

pause

Pauses program execution.

• Parameters:
  • threadId (number): Thread ID

State Inspection

threads

Lists all threads in the debugged process.

stack_trace

Gets the stack trace for a thread.

• Parameters:
  • threadId (number): Thread ID
  • startFrame (number, optional): Starting frame index
  • levels (number, optional): Number of frames to retrieve

scopes

Gets variable scopes for a stack frame and automatically fetches all variables within each scope.

• Parameters:
  • frameId (number): Stack frame ID
• Returns: A formatted display showing:
  • All available scopes (Locals, Arguments, Globals, etc.)
  • Variables within each scope with their names, types, and values
  • Variable references for compound types that can be further inspected

variables

Gets variables in a scope.

• Parameters:
  • variablesReference (number): Variables reference

evaluate

Evaluates an expression.

• Parameters:
  • expression (string): Expression to evaluate
  • frameId (number, optional): Frame context
  • context (string, optional): Evaluation context

set_variable

Sets a variable value.

• Parameters:
  • variablesReference (number): Variables reference
  • name (string): Variable name
  • value (string): New value

Additional Tools

loaded_sources

Lists all loaded source files.

modules

Lists loaded modules.

disassemble

Disassembles code at a memory location.

• Parameters:
  • memoryReference (string): Memory address
  • instructionOffset (number, optional): Instruction offset
  • instructionCount (number): Number of instructions

exception_info

Gets exception information.

• Parameters:
  • threadId (number): Thread ID

disconnect

Disconnects from the debugger.

• Parameters:
  • terminateDebuggee (boolean, optional): Whether to terminate the debuggee

configuration_done

Signals that configuration is complete.

Contributing

Contributions are welcome! Please feel free to submit a Pull Request.

License

MIT

Acknowledgments

• Built with the Model Context Protocol SDK for Go
• Uses the Google DAP implementation for Go