fusionctl and MCP
How fusionctl compares with Autodesk's Fusion MCP Server and community MCP servers, when each is the better choice, and how to use both.
Since May 2026 Autodesk ships an official Fusion MCP Server: a Model Context Protocol endpoint that runs inside the Fusion you have open, so an MCP client can drive it. fusionctl does a similar job from a different side: a command-line tool and a small add-in that any program with a shell can call. Both work against a live Fusion session, and they do not exclude each other.
This page sticks to what each project documents. It does not compare speed, reliability or token use: those have not been measured here.
What each one is
fusionctl is a third-party CLI for Bun, with the FusionBridge add-in that fusionctl install copies into Fusion. Each command is one HTTP request to 127.0.0.1:18765, run on Fusion's main thread (How it works & security). It uses the regular Fusion API for add-ins.
Autodesk Fusion MCP Server is built into Fusion and turned on in Preferences > General > API. Autodesk's overview describes it as running "locally, on the same machine as Fusion" for "real-time modeling and command execution in a live Fusion session", with Claude Desktop, Cursor and "any MCP-capable HTTP client" as clients. Autodesk's add-in tutorial connects Cursor to http://127.0.0.1:27182, the default port it shows. The same post mentions a Claude Desktop connector for Fusion, which it calls "an official, low-setup integration".
Autodesk Fusion Data MCP Server is a separate, cloud server for Fusion data (hubs, projects, folders, items). It does not need Fusion running and signs in with your Autodesk account. fusionctl has nothing like it.
Community MCP servers exist as well, for example frankhommers/autodesk-fusion-mcp (an add-in serving MCP over Streamable HTTP, with Python execution, viewport capture and API documentation lookup) and Autodesk's MIT-licensed reference sample FusionMCPSample (execute_api_script, get_screenshot, get_api_documentation). fusionctl's apidoc search is adapted from that sample.
Side by side
| fusionctl | Fusion MCP Server (Autodesk) | |
|---|---|---|
| Made by | Lucas Piera; unofficial, one maintainer, not affiliated with Autodesk | Autodesk, as part of Fusion |
| Set up | bun install -g github:pieralukasz/fusionctl, fusionctl install, restart Fusion | Enable it in Preferences > General > API, then point a client at it |
| Who can call it | Anything that runs a command: coding agents with a shell (Claude Code, Codex, OpenCode), shell scripts, Makefiles, CI, a person | MCP clients: Claude Desktop, Cursor, any MCP-capable HTTP client, per Autodesk |
| How the caller learns it | fusionctl --help and fusionctl <cmd> --help when needed; AGENTS.md and llms-full.txt | "Your client discovers available tools at connection time, and the tool set may evolve between releases" |
| Running Python | exec and run, from a string or a file | Per Autodesk's add-in tutorial, agents can "run test scripts in your active session" |
| API documentation | fusionctl apidoc TERM searches the installed build | Per Autodesk, the tools "pull current documentation" |
| Output | Tables on a terminal, JSON when piped or with --json; exit codes 0, 1, 2 | MCP tool results, shown in the client |
| Checks | timeline (health), bodies (volume and bounding box in world mm), interference, screenshot from eight named views, --atomic rollback | Whatever tools the server offers in your release |
| Authentication | Loopback only, token file (mode 600) on every request; requests with an Origin header are refused | "None — local connection only", per Autodesk's overview table |
| Platforms | Checked on macOS (Fusion 2705.1.30); the Windows path is in the code but untested | Fusion desktop; see the note on availability below |
| Cloud data | No | Through the separate Fusion Data MCP |
| Support | GitHub issues, one maintainer | Autodesk |
When the Fusion MCP is the better choice
- You work in a chat app without a terminal. Claude Desktop with Autodesk's Fusion connector needs no shell; fusionctl needs one.
- You want official support. It is Autodesk's server, documented in Fusion's help, with nothing third-party to install.
- You want Autodesk to maintain the tools. The tool set ships with Fusion; Autodesk notes it "may evolve between releases".
- You need cloud data. Listing hubs and projects without Fusion running is what the Fusion Data MCP is for.
When fusionctl fits
- The agent already works in a shell. Claude Code, Codex and OpenCode run
fusionctllike any other command, with no MCP configuration. So can a Makefile or a CI job. - The modelling should be files. Scripts live in git, get reviewed like code, and
fusionctl run part.py --atomicrepeats them. Parameters change withfusionctl params --set. - The agent must check its work. Each step can end with
timelineandbodies, which print numbers to compare against the spec, andscreenshotfor a picture.--atomicdeletes what a failing script added. - Help on demand. The agent reads
fusionctl <cmd> --helpwhen it needs a command, and AGENTS.md for the modelling rules.
Coding agents that speak MCP, such as Cursor or Claude Code, can use either one; the choice there is about files, checks and support rather than about the client.
Using both
fusionctl's bridge is its own add-in on port 18765; Autodesk's server is part of Fusion, on the port shown in its preferences (27182 in Autodesk's tutorial). Both can be on at once. One way to split the work: explore in a chat with the MCP server, then keep what worked as a script that fusionctl run repeats and checks.
Availability of the MCP setting
Autodesk documents the setting at Preferences > General > API. One Reddit user reported in May 2026 that they could not find it with an education licence on a Mac, and did find it on Windows (thread). Whether every licence, including personal use, includes it is not confirmed here: check that menu on your own install. fusionctl only needs the regular API for add-ins, which the personal-use licence includes.
Sources
- Autodesk, Autodesk Fusion MCPs Overview (Fusion help): local and cloud servers, Preferences > General > API, authentication, compatible clients, dynamic tooling.
- Autodesk Fusion blog, Introducing the Fusion MCP: Opening Fusion to AI-Powered Workflows, 7 May 2026.
- Autodesk Fusion blog, Build Your Own Fusion Add-ins with the Fusion MCP, 30 June 2026: the Claude Desktop connector, running test scripts in the active session, current documentation, port
27182. - r/Fusion360, user report on the MCP setting, May 2026.
- frankhommers/autodesk-fusion-mcp and AutodeskFusion360/FusionMCPSample on GitHub.
- fusionctl: README, How it works & security, Commands.
fusionctl is not affiliated with or endorsed by Autodesk. Autodesk and Fusion are trademarks of Autodesk, Inc.
Made by Lucas Piera. MIT licence. fusionctl is not affiliated with or endorsed by Autodesk; Autodesk and Fusion are trademarks of Autodesk, Inc.
How it works & security
The CLI sends one HTTP request per command to the FusionBridge add-in on 127.0.0.1, with a token. The add-in runs it on Fusion's main thread. exec runs arbitrary Python as your user.
Troubleshooting
What fusionctl doctor checks, and what to do about each error message, from a missing or outdated add-in, an unreachable bridge, a token mismatch, a modal dialog.