mcp-debugger

{
  "mcpServers": {
    "mcp-debugger": {
      "command": "npx",
      "args": [
        "-y",
        "@debugmcp/mcp-debugger"
      ]
    }
  }
}

claude mcp add --transport stdio mcp-debugger -- npx -y @debugmcp/mcp-debugger

{
  "mcpServers": {
    "mcp-debugger": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@debugmcp/mcp-debugger"
      ]
    }
  }
}

{
  "servers": {
    "mcp-debugger": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "-y",
        "@debugmcp/mcp-debugger"
      ]
    }
  }
}

Config formats checked against the official docs on Oct 7, 2026: modelcontextprotocol.io (opens in a new tab), code.claude.com (opens in a new tab), cursor.com (opens in a new tab), code.visualstudio.com (opens in a new tab).

• create_debug_session

  Create a new debugging session

• list_debug_sessions

  List all active sessions

• list_supported_languages

  Show available language adapters

• set_breakpoint

  Set a breakpoint in a file

• list_breakpoints

  List a session's breakpoints with verified state

• remove_breakpoint

  Remove a breakpoint by id or file+line

• clear_breakpoints

  Remove all breakpoints (optionally per file)

• start_debugging

  Start debugging a script

• restart_debugging

  Relaunch with the same config, breakpoints re-applied

• attach_to_process

  Attach debugger to a running process

• detach_from_process

  Detach debugger from a process

• expose_session

  Open a read-only DAP mirror endpoint so an IDE can attach and inspect

• unexpose_session

  Close the mirror endpoint and disconnect IDE clients

• get_stack_trace

  Get the current stack trace

• list_threads

  List all threads in the debug session

• get_scopes

  Get variable scopes for a frame

• get_variables

  Get variables in a scope

• get_local_variables

  Get local variables in current frame

• step_over

  Step over the current line

• step_into

  Step into a function

• step_out

  Step out of a function

• continue_execution

  Continue running

• wait_for_stop

  Block until the session next pauses or ends

• pause_execution

  Pause running execution

• evaluate_expression

  Evaluate expressions in debug context

• get_source_context

  Get source code context

• get_output

  Read captured debuggee output (stdout/stderr)

• close_debug_session

  Close a session

• redefine_classes

  Hot-swap changed Java classes into a running JVM (Java only)

A headless, agentic debugger over MCP — let your AI agents debug running programs in nine languages. mcp-debugger is a Model Context Protocol (MCP) server that exposes step-through debugging as structured tool calls. It lets AI agents set breakpoints, inspect variables, evaluate expressions, and step through running programs across nine languages — driving real language debuggers through the Debug Adapter Protocol (DAP).