x64dbg-MCP Server

MCP-powered agentic reverse engineering for x64dbg.

Features • Install • Usage • Tools • Configuration • Building • Structure

x64dbg-MCP Server is a native MCP (Model Context Protocol) plugin for x64dbg that exposes the debugger's full functionality over HTTP. Connect any MCP-compatible AI assistant and control x64dbg programmatically: set breakpoints, step through code, read memory, dump registers, and more.

Built with Zig — zero dependencies, single-binary output, cross-compiles to both x32 and x64 from any host. No .NET, no Python, no runtime — just drop the plugin into your x64dbg plugins folder and go.

MCP 2024-11-05 — Streamable HTTP + SSE transports, JSON-RPC 2.0.

Features

• 84 MCP Tools: Full debugger control — disassembly, stepping, breakpoints, memory allocation, registers, modules, threads, call stack, pattern scanning, string extraction, xrefs, symbols, bookmarks, PE analysis, OEP detection, module dumping, PEB/SEH inspection, tracing, and more.
• 22 Event Callbacks: Full debugger event coverage — init, stop, breakpoint, exception, step, attach/detach, DLL load/unload, threads, and more.
• Zero Dependencies: Pure native plugin, no runtime or framework needed.
• x32 and x64: Single codebase, builds both architectures from one command.
• Dual Transport: Streamable HTTP + SSE — compatible with any MCP client (new and legacy).
• Bearer Auth: Mandatory token authentication — auto-generated on first run, required on every request to prevent unauthorized access.
• Config Dialog: Change IP/port/token from the Plugins menu, auto-restarts the server on save.
• Auto-Start: MCP server starts automatically when x64dbg launches.
• Cross-Compile: Build Windows plugins from Linux, macOS, or WSL.

Install

Download the latest release or build from source:

1. Copy the contents of dist/ into your x64dbg root folder (deploys both x32 and x64)
2. Launch x64dbg

The MCP server starts automatically. Default ports:

• x64: 0.0.0.0:9094
• x32: 0.0.0.0:9095

Usage

Add to your MCP client config (.mcp.json, etc.):

Streamable HTTP (recommended):

{
  "mcpServers": {
    "x64dbg": {
      "type": "http",
      "url": "http://localhost:9094/",
      "headers": {
        "Authorization": "Bearer YOUR_TOKEN_HERE"
      }
    }
  }
}

SSE (legacy clients):

{
  "mcpServers": {
    "x64dbg": {
      "type": "sse",
      "url": "http://localhost:9094/sse",
      "headers": {
        "Authorization": "Bearer YOUR_TOKEN_HERE"
      }
    }
  }
}

If connecting from WSL or a remote machine, use the host's IP address and set the bind address to 0.0.0.0 in the config dialog.

Example — AI-assisted reverse engineering session:

You:    Load calc.exe and break at the entry point
AI: [calls LoadBinary, SetBreakpoint, run, WaitForPause]
        Loaded calc.exe, hit breakpoint at 0x7FF7A1234000 in calc.exe

You:    What are the current registers?
AI: [calls GetAllRegisters]
        RAX: 0x0, RCX: 0x7FF7A1234000, RDX: 0x1, ...

You:    Read 64 bytes at the current instruction pointer
AI: [calls ReadMemory]
        48 83 EC 28 E8 12 34 00 00 ...

You:    Step over the next 3 instructions and show me the stack
AI: [calls StepOver x3, GetCallStack]
        Stepped to 0x7FF7A1234010, call stack: ...

Tools

72 MCP tools covering the full x64dbg debugging workflow.

Always available

Tool	Description
GetDebugState	Current debugger state, PID, instruction pointer
LoadBinary	Load an executable into the debugger
ExecuteDebuggerCommand	Run any x64dbg command
ListCommandsByCategory	List available MCP tools
SearchForStrings	Search process memory for text
GetEventLog	Last N debugger events (exceptions, breakpoints, DLL loads)
ClearEventLog	Clear the event log
EvalExpression	Evaluate any x64dbg expression (address, register, arithmetic)
AttachProcess	Attach to a running process by PID
Echo	Echo input back
WaitForEvent	Long-poll for debugger events (breakpoint, pause, resume, exception)

Requires active debug session

Tool	Description
GetCurrentAddress	Current EIP/RIP with label and comment
Disassemble	Disassemble N instructions at an address
DisassembleFunction	Disassemble an entire function by boundaries
ReadMemory	Hex dump of process memory
WaitForPause	Block until target pauses
run	Resume execution (F9)
StepInto	Single-step into calls (F7)
StepOver	Step over calls (F8)
StepOut	Run until return (Ctrl+F9)
PauseDebug	Pause the target (F12)
StopDebug	Terminate debug session
RestartDebug	Restart debug session
SetBreakpoint	Set INT3 breakpoint at address/symbol
SetHardwareBreakpoint	Set hardware breakpoint (DR0-DR3, read/write/execute)
SetConditionalBreakpoint	Set breakpoint with condition expression and optional log
EnableBreakpoint	Enable a breakpoint at a given address
DisableBreakpoint	Disable a breakpoint without deleting it
ToggleBreakpoint	Toggle a breakpoint between enabled and disabled
DeleteBreakpoint	Remove a breakpoint
DeleteAllBreakpoints	Remove all breakpoints (normal, hardware, memory)
ResetHitCount	Reset a breakpoint's hit counter to zero
ListBreakpoints	List all active breakpoints
GetAllRegisters	Dump all general-purpose registers
SetRegister	Set a CPU register value
GetCallStack	Current thread call stack
GetThreads	List all threads with IDs and instruction pointers
SwitchThread	Switch active thread context
SuspendThread	Suspend a thread by its thread ID
ResumeThread	Resume a suspended thread
ListModules	List loaded modules with base addresses and sizes
GetMemoryMap	Memory regions with addresses, sizes, and protection
GetDumpableRegions	List committed, readable memory regions
AllocateMemory	Allocate memory in the target process
FreeMemory	Free allocated memory in the target process
WriteMemToAddress	Patch memory with hex bytes
RestorePatches	Restore all patches to original bytes
Assemble	Assemble an instruction at an address
CommentOrLabelAtAddress	Add comment/label in disassembly
SetBookmark	Set a bookmark at an address
DeleteBookmark	Delete a bookmark
ListBookmarks	List all bookmarks
GetImports	Show module import table
GetExports	Show module export table
SearchSymbols	Search for symbols matching a pattern
ListSymbols	List exported symbols of a module
GetPatches	List all memory patches
FindPattern	Scan module memory for byte pattern with ?? wildcards
GetStrings	Extract ASCII strings from a module's memory
GetReferences	Find CALL/JMP xrefs to a target address
GetFunctions	List analyzed functions with addresses and labels
AnalyzeModule	PE structure analysis: sections, EP, image size
DetectOEP	Detect Original Entry Point for packed executables
DumpMemory	Save memory region to file on disk
DumpModule	Dump an entire module to a file
RunToAddress	Run until hitting a specific address
TraceInto	Step N instructions recording address + disassembly
FollowPointer	Dereference pointer chain N levels deep
WatchExpressions	Evaluate multiple expressions in one call
GetSEHChain	Walk Structured Exception Handler chain (x32)
GetPEB	Read Process Environment Block fields
GetArguments	Read function arguments from stack/registers
SetMemoryBreakpoint	Set memory breakpoint (read/write/execute)
SetExceptionBreakpoint	Configure exception breakpoint (break or ignore, first/second/all chance)
DeleteExceptionBreakpoint	Delete an exception breakpoint
AnalyzeCode	Run code analysis (function, module, or control flow)
TraceOver	Trace N instructions stepping over calls
SetBreakpointCommand	Set a command to execute when a breakpoint is hit
SetBreakpointFastResume	Enable/disable fast resume (auto-continue) on a breakpoint
SaveDatabase	Save the x64dbg database (.dd64/.dd32)

Configuration

Go to Plugins > x64dbg-MCP Server > Configure MCP Server... to change the bind address, port, and auth token.

• 0.0.0.0 — listen on all interfaces (for WSL/remote access)
• 127.0.0.1 — local-only access

Authentication

A Bearer token is auto-generated on first run and required on every request. The MCP server has full debugger control and can read/write process memory — all requests without a valid token receive 401 Unauthorized. Click Generate in the config dialog to rotate the token, or Copy to copy it to clipboard. Clients must include the token as an Authorization: Bearer <token> header.

Changes take effect immediately — the server auto-restarts on save. Config is persisted to mcp_config.json next to the x64dbg executable.

Building

Requires Zig 0.16-dev or later. Builds on Windows, WSL, Linux, or macOS.

zig build -Doptimize=ReleaseSafe --prefix dist

Output mirrors x64dbg's folder structure — copy the contents of dist/ into your x64dbg root to deploy both architectures at once:

dist/
├── x32/
│   └── plugins/
│       └── x64dbg-MCP-Server.dp32
└── x64/
    └── plugins/
        └── x64dbg-MCP-Server.dp64

Project Structure

├── build.zig                     # build config — x32 + x64 cross-compilation
├── build.zig.zon                 # package manifest
└── src/
    ├── main.zig                  # plugin entry point, menu, callbacks
    ├── core/
    │   ├── bridge.zig            # x64dbg SDK bindings (runtime-resolved)
    │   ├── config.zig            # Win32 config dialog and persistence
    │   └── mcp_server.zig        # HTTP server and JSON-RPC dispatch
    ├── mcp/
    │   ├── json.zig              # JSON writer and parser helpers
    │   └── tools.zig             # MCP tool definitions and handlers
    └── resources/
        └── icons.zig             # embedded PNG icon data

How It Works

The plugin loads into x64dbg at startup, resolves the debugger's API symbols at runtime from x64bridge.dll and x64dbg.dll, then spins up an HTTP server on a background thread. MCP clients connect over HTTP and send JSON-RPC requests to invoke tools — each tool maps directly to x64dbg SDK calls (breakpoints, memory reads, command execution, etc.).

No polling, no external processes — the plugin lives inside x64dbg's address space with direct access to the debugger API.

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Disclaimer

This tool is intended for legitimate reverse engineering, malware analysis, security research, and educational purposes only. It provides full debugger control over running processes — including memory read/write, code execution, and process manipulation — over a network interface.

By using this software, you accept full responsibility for how it is used. The author is not liable for any misuse, damage, or legal consequences resulting from the use of this tool. Always ensure you have proper authorization before debugging or analyzing any software.

Do not expose the MCP server to untrusted networks. While Bearer token authentication is enforced, the server communicates over unencrypted HTTP.

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License

MIT. See LICENSE.

Made with 🖤 by @duty1g