MaxForge MCP

Lets an AI agent (Claude, or anything else that speaks MCP) drive a live 3ds Max session — not by generating scripts for a human to paste in, but by actually creating, editing, and animating objects in real time while Max is open.

Normally, getting an AI to help in 3ds Max means it writes a script and you run it yourself, blind to whether it actually worked. This closes that loop: the agent can query the real scene state before and after every action, catch its own mistakes, and iterate live instead of guessing.

What it can do

Every mutation is wrapped in a real undo block — anything the agent does is a normal Ctrl+Z away from being undone.

Related MCP server: Maya MCP Server

How it works

AI agent (MCP client) --stdio--> server/max_mcp_server.py --TCP, localhost only--> max_side/bridge.py (inside 3ds Max)

A small Python bridge runs inside 3ds Max, loaded via a startup script, and opens a socket bound to 127.0.0.1 only. An MCP server outside Max connects to it and exposes the tools above. Every command runs on Max's main thread via a Qt timer — the 3ds Max SDK isn't thread-safe, so commands arriving on a socket thread are queued and drained on the main loop rather than executed directly.

max_side/
  bridge.py      socket + main-thread queue (the only place pymxs is touched)
  commands.py    one function per tool, each wrapped in an undo block
  serialize.py   converts pymxs values (Point3, Matrix3, nodes, ...) to JSON
  startup_stub.ms   drop into Max's startup scripts folder
server/
  client.py         TCP client, newline-delimited JSON
  tools.py           MCP tool definitions
  max_mcp_server.py  the MCP server itself (stdio transport)

Setup

Requirements: 3ds Max 2022+ (pymxs), Python 3.10+ on the machine running the MCP server, uv.

1. Install dependencies

uv sync

2. Load the bridge into 3ds Max

Copy max_side/startup_stub.ms into Max's startup scripts folder — typically:

%LOCALAPPDATA%\Autodesk\3dsMax\<version>\ENU\scripts\startup\

Open the copied startup_stub.ms and set MAXFORGE_REPO_PATH to wherever you cloned this repo. It starts the bridge on port 47823 automatically the next time Max launches. Three macroscripts (category "MaxForge MCP") are also registered for manual control — Start / Stop / Reload — so you can pick up code changes without restarting Max.

3. Point an MCP client at it

For Claude Code:

claude mcp add maxforge -- <repo>\.venv\Scripts\python.exe <repo>\server\max_mcp_server.py

Or wire server/max_mcp_server.py into any other MCP-compatible client's config the same way.

Safety

The socket only ever binds to 127.0.0.1 — never the network. This is a code-execution endpoint sitting inside a modeling app; it's designed to only be reachable from the same machine it runs on.

Status

Live-tested against a running Max 2025 session with a full assertion-based suite (29/29 checks) covering every tool, every error path, and an undo/redo round trip.

create_collision_proxy currently only builds a generic axis-aligned box — it isn't tuned to any specific game engine's collision format yet.

Adding a new tool

1. Add a handler in max_side/commands.py, wrapped in undoable("MCP: ..."), registered in the COMMANDS dict.

2. Add a matching wrapper in server/tools.py — its docstring is what the agent sees.

3. Register it in the loop at the top of server/max_mcp_server.py.

4. Run the "Reload MaxForge Bridge" macroscript in Max instead of restarting.

License

Copyright (c) 2026 .bluntman420. — see LICENSE.md. Free to use as-is; modification and redistribution of modified versions is not permitted.