High Risk →

cancel_run

Cancel a running EnergyPlus simulation. Only works while status is

How to control cancel_run ↓

What cancel_run does on Openstudio

AI agents invoke cancel_run to trigger actions in Openstudio. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

High Risk

Why cancel_run needs a policy

This tool terminates an active simulation process. It is an execution-control action (stopping a running process), which falls under Execute. It does not delete data permanently (Destructive) nor does it create/modify model data (Write). The blast radius is medium — cancelling a simulation wastes compute and aborts results, but does not destroy stored model data.

From the tool's definition Cancel a running EnergyPlus simulation. Only works while status is [running]

Documented attack patterns abuse exactly the kind of access cancel_run gives an agent:

How to control cancel_run

PolicyLayer is an MCP gateway — it sits between your AI agents and Openstudio, and nothing reaches the server without passing your rules. This is the rule we recommend for cancel_run:

policy.json
{
  "version": "1",
  "default": "deny",
  "tools": {
    "cancel_run": {
      "limits": [
        {
          "counter": "cancel_run_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

cancel_run stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

  1. Create a free account and register Openstudio — nothing to install.
  2. Add this policy — paste it, or build it visually.
  3. Point your MCP client (Claude, Cursor, anything) at your gateway URL.
RATE-LIMIT THIS TOOL →

Free to start. No card required.

Related tools and policies

Go deeper

Questions about cancel_run

What does the cancel_run tool do? +

Cancel a running EnergyPlus simulation. Only works while status is. It is categorised as a Execute tool in the Openstudio MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on cancel_run? +

Register the Openstudio MCP server in PolicyLayer and add a rule for cancel_run: 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 Openstudio. Nothing to install.

What risk level is cancel_run? +

cancel_run is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit cancel_run? +

Yes. Add a rate_limit block to the cancel_run 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.

How do I block cancel_run completely? +

Set action: deny in the PolicyLayer policy for cancel_run. 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.

What MCP server provides cancel_run? +

cancel_run is provided by the Openstudio MCP server (natlabrockies/openstudio-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Openstudio tool call.

Start from Openstudio, 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.

146 Openstudio tools catalogued and risk-classified — across an index of 43,000+ MCP servers.

// GET IN TOUCH

Have a question or want to learn more? Send us a message.

Message sent.

We'll get back to you soon.