Set the fill color of a node in Figma can be TextNode or FrameNode
AI agents use set_fill_color to create or update resources in Figma Copilot — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Figma Copilot environment.
An AI agent can call set_fill_color faster than any human can review — one bad instruction and it creates or modifies resources in Figma Copilot by the hundred, each call as confident as the last.
Attacks that exploit this kind of access
Set the fill color of a node in Figma can be TextNode or FrameNode. It is categorised as a Write tool in the Figma Copilot MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.
Register the Figma Copilot MCP server in PolicyLayer and add a rule for set_fill_color: 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 Figma Copilot. Nothing to install.
set_fill_color 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 set_fill_color 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 set_fill_color. 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.
set_fill_color is provided by the Figma Copilot MCP server (xlzuvekas/figma-copilot). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.