CadAgent (SSSSSia)
FreeCAD plugin that assists modeling with an AI agent from text input.
What it does and how it connects
CadAgent is a FreeCAD workbench plugin that assists modeling with an AI agent from text input in Chinese or English. The agent runs a ReAct loop: it reasons, generates CadQuery-style chained code, executes it through a built-in translation layer that calls the FreeCAD Part API directly, analyzes the result and self-corrects over several rounds until the design is complete. No CadQuery install is needed.
It ships five agent tools: code execution, undo rollback, STEP, IGES, STL and OBJ export with an automatic quality check first, viewport screenshot analysis and reference image analysis. A CAD quality gate checks solid integrity, topological validity and dimensional sense after every execution and blocks the agent from finishing on a failing model. Named parameters in the code can be edited from the toolbar to deterministically rebuild the model with no LLM call.
Install by copying the folder into FreeCAD's Mod directory and configuring any OpenAI-compatible LLM service in a .env file or the settings panel, with seven provider presets. The README warns plainly that generated code runs directly in the local FreeCAD Python process and is not a sandbox: it can read and write files, make network requests and call system commands, so it should run only where the model service and inputs are trusted. It needs FreeCAD 1.0 or later.
Alternatives
Compare side by side- FreeCAD_MultiAI_Panel
A FreeCAD panel with an AI-assisted Python macro editor, many providers, a syntax checker, and natural-language-to-macro generation, rather than a ReAct agent that models from text.
- vibe-cading
CadQuery-based 3D model generators written for humans and LLM agents, rather than a FreeCAD plugin.
- parcad
Parametric CAD written as code with its own exact kernel and MCP surface, rather than a FreeCAD plugin.
- open-poly
A browser-based open source CAD tool with a constraint solver and MCP access, rather than a FreeCAD plugin.
- CADStudio
An AI-native parametric CAD environment for the web with an editable feature tree and CadQuery export, rather than a FreeCAD plugin.
Recurring errors it addresses
Error Index entries this tool is built to reduce or work around.
- When an agent fans out parallel create calls through the FreeCAD MCP bridge, the shared connection races: the first object is created even though its call reports failure, and the second object is silently never created with the status still showing healthy.Error Index
- A FreeCAD MCP bridge silently ignored parameters the client materialized from JSON-Schema defaults, so box(size=20) produced a default 10mm shape. The agent believes it built the requested geometry while the model is something else entirely.Error Index
- A FreeCAD MCP bridge's autosave-before-call rewrote the active document on every tool call even with zero unsaved changes, stamping phantom diffs onto git-tracked CAD files. Agent activity pollutes version control with edits no human authored.Error Index
- A FreeCAD user reports fillet/bevel as big weaknesses of FreeCAD and shows a fillet that breaks in FreeCAD and in the FreeCAD-Nxt add-on meant to fix it.Error Index
Sources
Not verified
- Pricing (no price stated; the user brings their own LLM API key)
- Real user voices (the repository has no public issues)
- A named individual builder beyond the repository owner handle SSSSia
Last verified November 6, 2026. Listings are informational. The evidence score measures public, verifiable evidence and is not an endorsement or a compatibility claim.