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

• Unified Debug Launch: Single debug tool handles source, binary, and attach modes
• Automatic Context: Execution control tools return full state (location, stack, variables)
• Streamlined API: 13 tools cover all debugging operations
• Breakpoint Management: Set line and function breakpoints, run-to-cursor
• Full State Inspection: Stack traces, scopes, and variables in one call
• Expression Evaluation: Evaluate and modify variables in context
• Process Attachment: Attach to running processes
• Disassembly Support: View disassembled code at memory addresses

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

Connecting via MCP

The server uses stdio transport, allowing AI agents to spawn it on-demand. Configure your MCP client with the path to the binary.

[!IMPORTANT] A debugger can launch programs, attach to processes, evaluate target code, inspect secrets, and alter or terminate a debuggee. Run this server only for a trusted, single-user MCP client under a least-privileged OS account. The stdio server has no HTTP listener or multi-tenant authorization layer. Delve's internal DAP socket is always bound to loopback.

Persistent server logging is disabled by default. Set MCP_DAP_LOG=1 to create a unique private log in the OS temporary directory. It is capped at 8 MiB and retained until manually deleted. Explicit protocol and GDB tool logs reject existing files; treat them as sensitive. GDB tool logs are written directly by GDB and are not size-capped.

Example MCP Client Configuration

This configuration works with Gemini CLI and similar MCP clients:

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

Claude Code Configuration

claude mcp add mcp-dap-server /path/to/mcp-dap-server

Available Tools

Session Management

debug

Start a debugging session. Supports four modes:

• source: Compile and debug Go source code
• binary: Debug a pre-compiled executable
• core: Debug a core dump file
• attach: Attach to a running process

Parameters:

• mode (string, required): One of 'source', 'binary', 'core', or 'attach'
• path (string): Path to source file or binary (required for source/binary modes; optional for core mode with GDB, which can auto-detect it)
• args (array): Arguments to pass to the program
• coreFilePath (string): Path to core dump file (required for core mode)
• processId (number): Process ID (required for attach mode)
• breakpoints (array): Breakpoints to set before running (file:line or function name)
• stopOnEntry (boolean): Stop at program entry point
• port (number): optional numeric Delve port (0 chooses an ephemeral loopback port; external bind addresses are not accepted)

Returns full context (location, stack trace, variables) when stopped.

stop

End the debugging session. Terminates the debuggee and stops the debugger.

restart

Restart the debugging session with optional new arguments.

• Parameters:
  • arguments (array, optional): New program arguments

Breakpoints

breakpoint

Set a breakpoint at a file:line location or on a function.

• Parameters (one of):
  • file (string) + line (number): Source file and line number
  • function (string): Function name

clear-breakpoints

Remove breakpoints from a file or clear all breakpoints.

• Parameters:
  • file (string, optional): Clear breakpoints in this file
  • all (boolean, optional): Clear all breakpoints

Execution Control

continue

Continue program execution. Optionally run to a specific location.

• Parameters:
  • to (object, optional): Run-to-cursor target (file+line or function)

Returns full context when stopped.

step

Step through code execution.

• Parameters:
  • mode (string, required): One of 'over', 'in', or 'out'

Returns full context at new location.

pause

Pause program execution.

• Parameters:
  • threadId (number): Thread ID to pause

State Inspection

context

Get full debugging context including current location, stack trace, and all variables.

• Parameters:
  • threadId (number, optional): Thread ID
  • frameId (number, optional): Stack frame ID

evaluate

Evaluate an expression in the current debugging context.

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

set-variable

Modify a variable's value in the debugged program.

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

Program Information

info

Get program metadata.

• Parameters:
  • type (string, required): One of 'sources' or 'modules'

disassemble

Disassemble code at a memory address.

• Parameters:
  • memoryReference (string): Memory address
  • instructionOffset (number, optional): Offset from address
  • instructionCount (number): Number of instructions to disassemble

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