Autodesk Fusion MCP Server

Standalone MCP server that runs inside Autodesk Fusion (formerly Autodesk
Fusion 360) as an add-in. AI agents connect over Streamable HTTP -- the
current MCP transport specification -- with no external proxy, middleware, or
dependencies required.

Highlights

Streamable HTTP transport -- implements the MCP Streamable HTTP spec
natively; no legacy SSE polling or sidecar servers.
Protocol negotiation -- speaks the 2025-11-25, 2025-06-18 and
2025-03-26 revisions and agrees on whichever the client asks for.
Zero external dependencies -- uses only Python's standard library and
the Fusion SDK (adsk.*).
Thread-safe bridge -- HTTP requests are relayed to Fusion's main thread
via a Custom Event / work-queue dispatcher, preventing crashes.
11 dedicated MCP tools -- each with a clean, focused schema for better
LLM tool selection.

Supported Platforms

Windows
Mac OS

Installation

Option A: Install from release zip (recommended)

Download AutodeskFusionMCP-v*.zip from the
Releases
page.
Extract the zip into your Fusion add-ins folder:
- macOS: ~/Library/Application Support/Autodesk/Autodesk Fusion 360/API/AddIns/
- Windows: %APPDATA%\Autodesk\Autodesk Fusion 360\API\AddIns\
Make sure the extracted folder is named AutodeskFusionMCP (rename it if
the zip extracts to a different name).
Open Fusion, press Shift+S, select the Add-Ins tab, and run
AutodeskFusionMCP.
The server listens on http://127.0.0.1:8765/mcp.

Option B: Clone from source

Clone this repository into your Fusion add-ins folder:
- macOS: ~/Library/Application Support/Autodesk/Autodesk Fusion 360/API/AddIns/
- Windows: %APPDATA%\Autodesk\Autodesk Fusion 360\API\AddIns\
Make sure the directory is named AutodeskFusionMCP.
Open Fusion, press Shift+S, select the Add-Ins tab, and run
AutodeskFusionMCP.
The server listens on http://127.0.0.1:8765/mcp.

MCP Client Configuration

Add to your MCP client config (Claude Desktop, Cursor, etc.):

{
  "mcpServers": {
    "autodesk-fusion-mcp": {
      "type": "http",
      "url": "http://127.0.0.1:8765/mcp"
    }
  }
}

Tools

Tool	Description
`call_autodesk_api`	Execute a generic Fusion API call via dotted path
`execute_python`	Run Python code inside the live Fusion session
`capture_viewport`	Capture the viewport as a PNG image
`get_active_selection`	Get objects currently selected in the viewport
`fetch_api_documentation`	Search Fusion API metadata via runtime introspection
`fetch_online_documentation`	Fetch Autodesk cloudhelp docs for a class/member
`fetch_design_guide`	Read the bundled design guide
`save_script`	Save a reusable Python script
`load_script`	Load a previously saved script
`list_scripts`	List saved scripts with metadata
`delete_script`	Delete a saved script

Generic API example

{
  "api_path": "rootComponent.sketches.add",
  "args": ["rootComponent.xYConstructionPlane"],
  "remember_as": "my_sketch"
}

Path shortcuts: app, ui, design, rootComponent, $stored_name.

Constructors accepted in args: Point3D, Vector3D, Point2D,
ValueInput, ObjectCollection, Matrix3D.

Selection example

The get_active_selection tool returns details of objects selected in the
viewport and stores them as $selection_0, $selection_1, etc. for use in
follow-up API calls.

Architecture

AI agent
  |  Streamable HTTP (POST/GET/DELETE /mcp)
  v
lib/mcp_server.py           -- HTTP server (threading, stdlib only)
  |
fusion_bridge/dispatch.py   -- Custom Event queue relay
  |
fusion_bridge/operations.py -- per-tool routing
  |
fusion_bridge/selection.py  -- viewport selection reader
fusion_bridge/python_exec.py -- Python execution
fusion_bridge/viewport.py   -- viewport capture
fusion_bridge/doc_lookup.py -- API docs introspection
fusion_bridge/script_store.py -- script CRUD
  |
adsk.core / adsk.fusion     -- Fusion 360 SDK (main thread)

Testing

Unit tests

Run the test suite (no Fusion required):

python3 -m unittest discover -s tests

CI runs these tests on every push and pull request via GitHub Actions.

Protocol compliance with MCP Inspector

The official MCP Inspector
can verify Streamable HTTP compliance against a running server.

Against the live Fusion add-in (port 8765):

npx @modelcontextprotocol/inspector --cli http://127.0.0.1:8765/mcp --transport http --method tools/list

Against the standalone test server (no Fusion required):

python3 test_server.py                  # starts a dummy server on port 9765
npx @modelcontextprotocol/inspector --cli http://127.0.0.1:9765/mcp --transport http --method tools/list

Reporting Issues

Please report any issues on the Issues page.

Author

Frank Hommers / Initialize

License

This project is licensed under the terms of the MIT license. See LICENSE.

Changelog

v 1.1.0
- Negotiate the MCP protocol version instead of always answering
  2025-03-26; 2025-11-25 and 2025-06-18 are now supported, which fixes
  clients refusing to connect (#1)
- Tolerate the MCP-Protocol-Version request header introduced in 2025-06-18
- /health now reports supported_protocols
- Fixed fetch_online_documentation silently dropping the syntax field
  after Autodesk changed its help markup from <strong> to <b>
- Per-command execution duration and ISO 8601 timestamps in the log
- CI now runs on Python 3.14, matching the interpreter Fusion bundles
v 1.0.0
- Initial release
- 11 dedicated MCP tools with individual schemas
- Streamable HTTP transport (MCP spec 2025-03-26)
- Thread-safe main-thread dispatch
- Viewport selection reader (get_active_selection)
- Python code execution with persistent sessions
- API documentation introspection
- Script management (save/load/list/delete)
- Zero external dependencies