Mcdev MCP Server

MCP server for Minecraft mod development - provides decompiled code access, symbol search, and runtime interaction via DebugBridge

Local serverstdioPython

What is the Mcdev MCP MCP server?

Mcdev MCP MCP server is a locally run integration for AI assistants that speak the Model Context Protocol. MCP server for Minecraft mod development - provides decompiled code access, symbol search, and runtime interaction via DebugBridge.

What you get

An MCP (Model Context Protocol) server that empowers AI coding agents to work effectively with Minecraft mod development. Provides both static analysis of decompiled source code and runtime interaction with a running Minecraft instance.

What the assistant can call

Once Mcdev MCP is connected, these are the calls the assistant has available:

  • mc_run_command — MCDEV_RUN_COMMAND=1 (or true)
  • mc_script_logs — MCDEV_SCRIPT_LOGS=1 (or true)
  • serve — Start the MCP server over stdio (launched by MCP clients — not run by humans)
  • status — Show all initialized versions and what stage each one is at
  • mc_version — Manage the active Minecraft version. Call with action: "set" before other static tools, or action: "list" to see what's initialized
  • mc_search — Search decompiled source code for classes, methods, or fields by name pattern
  • mc_get_class — The mc_get_class tool exposed by this server
  • mc_get_method — The mc_get_method tool exposed by this server
  • mc_find_refs — Find who calls a method (callers) or what it calls (callees)
  • mc_list_classes — List all classes under a specific package path (includes subpackages)
  • mc_list_packages — List all available packages. Optionally filter by namespace
  • mc_find_hierarchy — Find classes that extend or implement a given class or interface

Configuration and credentials

| Dependency | Version | Purpose | |------------|---------|---------| | Node.js | 18+ | Runtime | | Java | 8+ | Decompilation (Vineflower) & callgraph | | ~2GB | disk | Decompiled sources + cache | > Note: Java 17+ is recommended for the callgraph command due to Gradle compatibility.

Setting it up

mcdev-mcp on npm is all you need. Most clients run it directly, so configuration is a few lines and a restart.

Choosing this one

Among the developer tooling options, the useful question is rarely "what can it do" but "what does it cost you to run" — permissions, credentials, and how much of your context its toolset consumes. Mcdev MCP's toolset — mc_run_command, mc_script_logs, serve and 11 more — is a fair guide to whether it matches your workflow. It is maintained by weikengchen; worth a glance at recent repository activity before you build anything load-bearing on it.

SyncDev reviews every entry in this directory against the project's own documentation before publishing, and revisits them as servers change.

Before you rely on it

  • It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
  • With 14 tools registered it takes up a noticeable share of the context window; turn it off in projects that never touch Mcdev MCP.
  • MCP clients confirm each tool call by default. Leave that on until you have watched what the mcdev mcp mcp server does with a few real requests.

Available tools

ToolWhat it does
mc_run_commandMCDEV_RUN_COMMAND=1 (or true)
mc_script_logsMCDEV_SCRIPT_LOGS=1 (or true)
serveStart the MCP server over stdio (launched by MCP clients — not run by humans)
statusShow all initialized versions and what stage each one is at
mc_versionManage the active Minecraft version. Call with action: "set" before other static tools, or action: "list" to see what's initialized.
mc_searchSearch decompiled source code for classes, methods, or fields by name pattern.
mc_get_classThe mc_get_class tool exposed by this server.
mc_get_methodThe mc_get_method tool exposed by this server.
mc_find_refsFind who calls a method (callers) or what it calls (callees).
mc_list_classesList all classes under a specific package path (includes subpackages).
mc_list_packagesList all available packages. Optionally filter by namespace.
mc_find_hierarchyFind classes that extend or implement a given class or interface.
mc_connectConnect to a running Minecraft instance. Other runtime tools auto-connect if needed. Pass reset: true to disconnect and clear state before reconnecting (useful when switching instances). If port is omitted, scans ports 9
mc_executeExecute Groovy code in the running game. The binding persists across calls, and mc / player / level are pre-bound. (The runtime migrated from Lua to Apache Groovy 5 in mid-2026 — the tool description carries a Lua→Groovy

How to install the Mcdev MCP MCP server

{
  "mcpServers": {
    "mcdev": {
      "command": "npx",
      "args": ["-y", "mcdev-mcp", "serve"]
    }
  }
}

Configuration as documented by the project. Restart the client after saving.

Configuration

| Dependency | Version | Purpose | |------------|---------|---------| | Node.js | 18+ | Runtime | | Java | 8+ | Decompilation (Vineflower) & callgraph | | ~2GB | disk | Decompiled sources + cache | > Note: Java 17+ is recommended for the callgraph command due to Gradle compatibility.

Example prompts to try

  • Use Mcdev MCP to mc run command.
  • Use Mcdev MCP to mc script logs.
  • Use Mcdev MCP to serve.

Frequently asked questions

It connects Mcdev MCP to MCP-compatible AI assistants such as Claude and Cursor, exposing 14 tools (mc_run_command, mc_script_logs, serve, and more) that the assistant can call on your behalf. Instead of copying data back and forth by hand, the assistant works with Mcdev MCP directly.