Insert a part from the parts library addon. Args: relative_path: The relative path of the part to insert. Returns: A message indicating the success or failure of the part insertion and a screenshot of the object.
AI agents use insert_part_from_library to create or update resources in Freecad mcp — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Freecad mcp environment.
This tool creates and inserts a new part object into the FreeCAD document, which is a reversible modification of the document. It does not execute arbitrary code or irreversibly delete data, placing it in the Write category.
From the tool's definition insert_part_from_library creates or adds a new part object to the FreeCAD document from a library source, modifying the document state. The description states it 'Insert[s] a part' which is a create/add operation.
Documented attack patterns abuse exactly the kind of access insert_part_from_library gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Freecad mcp, and nothing reaches the server without passing your rules. This is the rule we recommend for insert_part_from_library:
{
"version": "1",
"default": "deny",
"tools": {
"insert_part_from_library": {
"limits": [
{
"counter": "insert_part_from_library_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}insert_part_from_library stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.
Free to start. No card required.
Insert a part from the parts library addon. Args: relative_path: The relative path of the part to insert. Returns: A message indicating the success or failure of the part insertion and a screenshot of the object. It is categorised as a Write tool in the Freecad mcp MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Freecad MCP server in PolicyLayer and add a rule for insert_part_from_library: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Freecad mcp. Nothing to install.
insert_part_from_library is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.
Yes. Add a rate_limit block to the insert_part_from_library rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.
Set action: deny in the PolicyLayer policy for insert_part_from_library. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.
insert_part_from_library is provided by the Freecad MCP server (neka-nat/freecad-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Freecad mcp, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.
Free to start. No card required.
14 Freecad mcp tools catalogued and risk-classified — across an index of 43,000+ MCP servers.