set_actor_property

Set a property on an actor via the Remote Control API.

SERVERUnreal SOURCE@jjpxdev/unreal-mcp

Medium RISK CLASS

Category Write

Parameters 32 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/jjpxdev-unreal-mcp/set-actor-property.md

WHAT IT DOES

What set_actor_property does on Unreal

AI agents use set_actor_property to create or update resources in Unreal, usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Unreal environment.

Parameter	Type	Required	Description
`actor_path`	string	Yes	Full object path of the actor (e.g., /Game/Level.Level:PersistentLevel.MyActor)
`property_name`	string	Yes	Property name to set
`property_value`	object	—	Value to set

Parameters from the server's own tool schema.

RISK

Why set_actor_property is rated Medium

This tool modifies actor properties in Unreal Engine, which are reversible changes that affect game objects and their state. While not destructive (properties can be reset), it qualifies as Write because it alters existing data.

From the tool's definition Tool name 'set_actor_property' and description 'Set a property on an actor via the Remote Control API' explicitly indicate modification of actor properties.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs set_actor_property safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Unreal, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For set_actor_property, this is the rule to start with:

set_actor_property Rate-limited

set_actor_property 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.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "set_actor_property": {
      "limits": [
        {
          "counter": "set_actor_property_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Unreal, apply this rule, and every set_actor_property call is checked against it from then on.

FAQ

Questions about set_actor_property

What does the set_actor_property tool do? +

Set a property on an actor via the Remote Control API. It is categorised as a Write tool in the Unreal MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

What parameters does set_actor_property accept? +

set_actor_property accepts 3 parameters: actor_path, property_name, property_value. Required: actor_path, property_name. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on set_actor_property? +

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

What risk level is set_actor_property? +

set_actor_property is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit set_actor_property? +

Yes. Add a rate_limit block to the set_actor_property 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 set_actor_property completely? +

Set action: deny in the PolicyLayer policy for set_actor_property. 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 set_actor_property? +

set_actor_property is provided by the Unreal MCP server (@jjpxdev/unreal-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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