Import a model file into the MCP workdir for reproducible .include usage.
AI agents use importModelFile to create or update resources in Ltspice — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Ltspice environment.
The tool writes/imports a model file into a directory for later use in simulations. This is a Write operation (creates/modifies files reversibly). Severity is medium because importing untrusted model files could introduce malicious circuitry definitions or cause simulation issues, but the effect is constrained to the workdir and is reversible.
From the tool's definition 'Import a model file into the MCP workdir' — creates or adds a file to a working directory, which is a reversible modification of the file system state.
Documented attack patterns abuse exactly the kind of access importModelFile gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and Ltspice, and nothing reaches the server without passing your rules. This is the rule we recommend for importModelFile:
{
"version": "1",
"default": "deny",
"tools": {
"importModelFile": {
"limits": [
{
"counter": "importmodelfile_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
}importModelFile 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.
Import a model file into the MCP workdir for reproducible .include usage. It is categorised as a Write tool in the Ltspice MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Ltspice MCP server in PolicyLayer and add a rule for importModelFile: 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 Ltspice. Nothing to install.
importModelFile 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 importModelFile 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 importModelFile. 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.
importModelFile is provided by the Ltspice MCP server (xuio/ltspice-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from Ltspice, 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.
71 Ltspice tools catalogued and risk-classified — across an index of 43,000+ MCP servers.