CADAgent
Conversational 3D modeling assistant that replaces menu diving with natural-language part creation and edits.
What it does and how it connects
CADAgent is an AI-powered CAD modeling assistant for Autodesk Fusion 360. The user describes what they want in plain English, and CADAgent builds it: a Fusion 360 add-in sends the request to a backend over a websocket and applies the returned CAD operations. The website describes it as a free, open source Fusion 360 add-in that turns intent into editable CAD.
The repository holds the whole product: the Fusion 360 add-in for macOS and Windows, a FastAPI backend that turns natural-language requests into tool calls the add-in executes, reference AWS deployment templates, and Supabase auth and quota migrations. The backend is self-hosted: the user runs it locally or on their own server, since the hosted backend at ws.cadagentpro.com is shut down.
To use it, the user downloads the add-in release, copies it into Fusion's add-ins directory, restarts Fusion 360, and runs it from Tools, Add-Ins, CADAgent, Run, then types a request such as 'Create a 5cm cube' and clicks Execute. The backend listens on a local websocket with a health check at /health, and the add-in is pointed at it through a BACKEND_HOST setting.
What engineers report
CADAgent installs correctly and loads inside Fusion 360, but is unable to establish a secure WebSocket connection to its backend server.
2026-07-18Read the original
Alternatives
Compare side by side- SolidCraft
SolidCraft is a parametric 3D CAD application with a built-in MCP server, while CADAgent is a Fusion 360 add-in driven by a self-hosted backend.
- agentcad
agentcad is a CLI and MCP server over build123d scripts, while CADAgent is a Fusion 360 add-in driven by a self-hosted backend.
- CAD-MCP
CAD-MCP drives AutoCAD, GstarCAD, and ZWCAD through an MCP server, while CADAgent is a Fusion 360 add-in driven by a self-hosted backend.
- Serpentine3D
Serpentine3D is a standalone NURBS modeller with an assistant, while CADAgent is a Fusion 360 add-in driven by a self-hosted backend.
- MecAgent
MecAgent is a commercial AI agent for CAD, while CADAgent is a free open-source Fusion 360 add-in with a self-hosted backend.
Recurring errors it addresses
Error Index entries this tool is built to reduce or work around.
- Cloud-first file model makes local file control, rename/move/backup workflows feel alien and risky.Error Index
- General UI/UX is described as confusing and hostile for routine work.Error Index
- ChatGPT's Computer Use agent cannot drive Autodesk Fusion 360: selecting Always allow does not stick, a later window-state request fails with 'Computer Use was not approved to use fusion360', and the requested CAD design could not be created. Desktop logs recorded three allow-persist-always approvals with no persisted entry in the config.Error Index
Sources
Not verified
- A named individual builder beyond the er-fo repository owner
- An up-to-date install package matching the latest release (the README install links point to v1.0.4 downloads while the latest release is v1.1.2)
Last verified November 6, 2026. Listings are informational. The evidence score measures public, verifiable evidence and is not an endorsement or a compatibility claim.