FreeCAD MCP is a Model Context Protocol server and FreeCAD add-on that let AI clients control the FreeCAD computer-aided design application. Users can ask Claude Desktop or another MCP client to create and edit models, run Python, inspect documents, and perform finite element analysis, with the catalogue instruction supporting this integration.
Borrowing it
Nothing to install: this file belongs to neka-nat/freecad-mcp. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/neka-nat/freecad-mcp/main/AGENTS.mdgit clone --depth 1 https://github.com/neka-nat/freecad-mcpWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/neka-nat/freecad-mcp/agents-md)<a href="https://agentmods.dev/instructions/neka-nat/freecad-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/neka-nat/freecad-mcp/agents-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/neka-nat/freecad-mcp/agents-md"><img src="https://agentmods.dev/badge/instructions/neka-nat/freecad-mcp/agents-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00605 | $0.00605 |
| Opus 5.5 | $0.00242 | $0.00242 |
| Sonnet 5.5 | $0.00121 | $0.00121 |
| Haiku 4.5 | $0.00060 | $0.00060 |
Grade A, and why
freecad-mcp AGENTS.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured today.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 22 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Repository Guidelines
Project Structure & Module Organization
src/freecad_mcp/ contains the packaged MCP server and CLI entrypoint exposed as freecad-mcp. addon/FreeCADMCP/ is the FreeCAD addon loaded inside FreeCAD, with XML-RPC and toolbar logic under rpc_server/. examples/ holds integration samples for ADK and LangChain. assets/ stores README media, while results/ and dist/ contain sample outputs and built distributions rather than core source.
Build, Test, and Development Commands
uv sync installs the pinned Python environment from uv.lock. uv run freecad-mcp --help verifies the CLI entrypoint; use uv run freecad-mcp --host localhost --only-text-feedback for a local MCP run against an existing FreeCAD RPC server. uv run python -m compileall src addon is the current fast validation pass for syntax issues. uv build creates the wheel and source distribution in dist/.
For addon testing, copy addon/FreeCADMCP into your FreeCAD Mod/ directory, restart FreeCAD, switch to the MCP Addon workbench, and start the RPC server from the FreeCAD MCP toolbar.
Coding Style & Naming Conventions
Target Python 3.12, use 4-space indentation, and add type hints to new or modified code. Follow the existing split: MCP transport and CLI code in src/, FreeCAD GUI and RPC behavior in addon/. Use snake_case for modules, functions, and variables, PascalCase for classes, and keep command IDs consistent with existing strings such as "Start_RPC_Server". Keep docstrings brief and move FreeCAD-specific side effects into small helper functions where practical.
Testing Guidelines
There is no committed automated test suite yet. For every change, run uv run python -m compileall src addon and perform a manual smoke test in FreeCAD for the affected workflow, such as local RPC, remote connections, auto-start, or headless mode. When adding pure-Python logic that can be tested outside FreeCAD, add pytest tests in a new tests/ package and name files test_*.py.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- today First seen · 22 lines · 605 tokens per session scan A 1b8d3eaa45db
freecad-mcp AGENTS.md is an instructions file published in the GitHub repository neka-nat/freecad-mcp (3,246 stars, last pushed today), licensed MIT. It adds 605 tokens to every session, about $0.0024 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-11-07.
freecad-mcp AGENTS.md compared with instructions from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| freecad-mcp AGENTS.mdneka-nat/freecad-mcp | Instructions file | 3.2k | today | MIT | A | 605 | Codex, OpenCode |
| vscode buildNext.instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 9,719 | GitHub Copilot |
| next.js AGENTS.mdvercel/next.js | Instructions file | 143k | today | MIT | A | 7,461 | Codex, OpenCode |
| vscode oss-third-party-notices.instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 5,516 | GitHub Copilot |
| langchain AGENTS.mdlangchain-ai/langchain | Instructions file | 149k | today | MIT | A | 4,680 | Codex, OpenCode |
| vscode copilot-instructions.mdmicrosoft/vscode | Instructions file | 195k | today | MIT | A | 3,093 | GitHub Copilot |
| deepseek-harness AGENTS.mddeepseek-ai/deepseek-harness | Instructions file | 275k | 3d ago | MIT | A | 4,313 | Codex, OpenCode |