dcc-mcp-3dsmax 0.1.6

3ds Max plugin for the DCC Model Context Protocol (MCP) ecosystem — embeds a Streamable HTTP MCP server directly inside 3ds Max

dcc-mcp-3dsmax

3ds Max plugin for the DCC Model Context Protocol (MCP) ecosystem.

Status: This project is under active development. APIs, packaging, and 3ds Max integration details may change quickly while the adapter tracks the latest dcc-mcp-core releases.

Features

• Sidecar MCP Server: Starts dcc-mcp-server.exe sidecar and keeps 3ds Max scene edits on the main thread
• Progressive Skill Loading: Discover skills without loading them immediately
• Shared Gateway: Registers with the stable gateway at http://127.0.0.1:9765/mcp
• Job Persistence: SQLite-based job storage for long-running operations
• Prometheus Metrics: Optional /metrics endpoint for monitoring

Installation

pip install dcc-mcp-3dsmax

Quickstart (inside 3ds Max MAXScript Listener)

import dcc_mcp_3dsmax

# Start on a random instance port; the public gateway stays fixed.
server = dcc_mcp_3dsmax.start_server()

# Progressive loading — discover skills without loading them immediately
n = server.discover_skills()        # scan paths, register tool metadata
server.load_skill("3dsmax-scene")  # lazy-load a specific skill

dcc_mcp_3dsmax.stop_server()

Sidecar Bridge

Start the sidecar bootstrap inside 3ds Max:

python.ExecuteFile @"C:\path\to\dcc-mcp-3dsmax\examples\start_sidecar_bridge.py"

This starts the random-port /dispatch bridge for main-thread scene edits, a random-port qtserver:// bridge for the sidecar process, and registers the 3ds Max instance with the stable gateway at http://127.0.0.1:9765/mcp. See docs/SIDECAR.md.

The bootstrap also installs a DCC MCP menu with Start Sidecar, Stop Sidecar, Open Gateway Admin, and Print Status commands. 3ds Max shutdown triggers the same stop path via #preSystemShutdown, so the sidecar process and local bridges are cleaned up when the host exits.

Skill Development

Create a skill with SKILL.md metadata file and Python scripts:

# my_skill/action_create_box.py
from dcc_mcp_3dsmax.api import max_success, with_max

@with_max
def main(width: float = 100.0, height: float = 100.0, depth: float = 100.0) -> dict:
    import pymxs
    rt = pymxs.runtime

    box_obj = rt.Box(width=width, height=height, depth=depth)
    return max_success("Created box", object_name=str(box_obj))

Environment Variables

Variable	Description	Default
DCC_MCP_3DSMAX_METRICS	Enable Prometheus /metrics endpoint	0
DCC_MCP_3DSMAX_JOB_STORAGE	Path to SQLite job database	platform default
DCC_MCP_3DSMAX_DISABLE_EXECUTE_PYTHON	Disable execute_python tool	0
DCC_MCP_3DSMAX_DISABLE_ARBITRARY_SCRIPT	Disable all arbitrary script execution	0
DCC_MCP_3DSMAX_ENABLE_GATEWAY_FAILOVER	Enable gateway failover	1
DCC_MCP_3DSMAX_SKILL_PATHS	Extra skill search paths (semicolon-separated)	None
DCC_MCP_3DSMAX_BRIDGE_PORT	Sidecar bridge localhost port	random
DCC_MCP_3DSMAX_SIDECAR_LOG	Explicit stdout/stderr log file for the sidecar subprocess	platform log dir
DCC_MCP_3DSMAX_SIDECAR_LOG_DIR	Directory for default sidecar stdout/stderr logs	core log dir
DCC_MCP_3DSMAX_SIDECAR_LOG_RETENTION_DAYS	Days to keep default sidecar logs	14
DCC_MCP_3DSMAX_SIDECAR_LOG_MAX_BYTES	Rotate a default sidecar log after this size	10485760
DCC_MCP_3DSMAX_SIDECAR_LOG_MAX_FILES	Rotated default sidecar log files to keep	5
DCC_MCP_3DSMAX_BOOTSTRAP_PATHS	Extra package Python roots for startup bootstrapping	None
DCC_MCP_PYTHONPATHS	Shared package Python roots for Rez/pipeline launchers	None
DCC_MCP_3DSMAX_ROOT	Adapter package root; startup probes python, python37, src, and root	None
DCC_MCP_CORE_ROOT	dcc-mcp-core package root; startup probes python, python37, src, and root	None
DCC_MCP_SERVER_ROOT	dcc-mcp-server package root; startup probes Python roots and sidecar binary locations	None
DCC_MCP_SERVER_BIN	Explicit dcc-mcp-server executable path	auto-detect
DCC_MCP_REGISTRY_DIR	Optional shared gateway/sidecar registry override	core default

For Rez-style deployment, launch 3ds Max with package roots in the environment instead of copying packages into the user scripts folder. A pipeline package cache can expose paths such as <package-cache>/dcc_mcp_core, <package-cache>/dcc_mcp_3dsmax, and <package-cache>/dcc_mcp_server through the root variables above. The MZP installer uses isolated version directories under <user scripts>/dcc_mcp_3dsmax/versions/, so installing a new payload does not delete the version that may already be loaded by the running 3ds Max process. After install, the active payload is added to sys.path, obsolete payload directories are cleaned up where possible, and the sidecar bridge is started. The generated startup script repeats that activation on future 3ds Max launches, so the bridge comes back automatically after restart. Uninstall cleanup uses the import-light lifecycle helpers from dcc-mcp-core when available, so locked native files are reported as restart-required instead of disappearing into a generic PermissionError.

Requirements

• 3ds Max 2017 or later (Python 3.x with pymxs support)
• Python >= 3.7
• dcc-mcp-core >= 0.17.23
• dcc-mcp-server >= 0.17.23

License

MIT