Thaw a frozen layer, making it visible and selectable again.
AI agents use layer_thaw to create or update resources in AutoCAD MCP Pro — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your AutoCAD MCP Pro environment.
Thawing a frozen layer is a reversible modification operation that changes drawing state without destroying data or executing arbitrary code. It falls under Write category as it modifies layer attributes (visibility/selectability).
From the tool's definition tool description states 'Thaw a frozen layer, making it visible and selectable again' - this modifies layer state (visibility and selectability) in the CAD drawing, which is a reversible change to drawing properties
Documented attack patterns abuse exactly the kind of access layer_thaw gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and AutoCAD MCP Pro, and nothing reaches the server without passing your rules. This is the rule we recommend for layer_thaw:
{
"version": "1",
"default": "deny",
"tools": {
"layer_thaw": {
"limits": [
{
"counter": "layer_thaw_rate",
"window": "minute",
"max": 30,
"scope": "grant"
}
]
}
}
} layer_thaw 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.
Thaw a frozen layer, making it visible and selectable again. It is categorised as a Write tool in the AutoCAD MCP Pro MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the AutoCAD MCP Pro MCP server in PolicyLayer and add a rule for layer_thaw: 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 AutoCAD MCP Pro. Nothing to install.
layer_thaw 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 layer_thaw 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 layer_thaw. 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.
layer_thaw is provided by the AutoCAD MCP Pro MCP server (u-c4n/autocad-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Start from AutoCAD MCP Pro, 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.
108 AutoCAD MCP Pro tools catalogued and risk-classified — across an index of 43,000+ MCP servers.