Get all node definitions from the running ComfyUI instance (GET /object_info). Returns class names and categories. Requires ComfyUI to be running at COMFYUI_HOST.
Part of the ComfyUI Builder server.
Free to start. No card required.
AI agents call discover_nodes_live to retrieve information from ComfyUI Builder without modifying any data. This is common in research, monitoring, and reporting workflows where the agent needs context before taking action. Because read operations don't change state, they are generally safe to allow without restrictions -- but you may still want rate limits to control API costs.
Even though discover_nodes_live only reads data, uncontrolled read access can leak sensitive information or rack up API costs. An agent caught in a retry loop could make thousands of calls per minute. A rate limit gives you a safety net without blocking legitimate use.
Read-only tools are safe to allow by default. No rate limit needed unless you want to control costs.
{
"version": "1",
"default": "deny",
"tools": {
"discover_nodes_live": {}
}
}See the full ComfyUI Builder policy for all 60 tools.
These attack patterns abuse exactly the kind of access discover_nodes_live gives an agent. Each links to the full case and the policy that stops it:
Other read tools across the catalogue. The same approach applies to each: allow, with a rate cap to control cost.
Get all node definitions from the running ComfyUI instance (GET /object_info). Returns class names and categories. Requires ComfyUI to be running at COMFYUI_HOST.. It is categorised as a Read tool in the ComfyUI Builder MCP Server, which means it retrieves data without modifying state.
Register the ComfyUI Builder MCP server in PolicyLayer and add a rule for discover_nodes_live: 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 ComfyUI Builder. Nothing to install.
discover_nodes_live is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the discover_nodes_live 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 discover_nodes_live. 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.
discover_nodes_live is provided by the ComfyUI Builder MCP server (mcp-comfy-ui-builder). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 60 ComfyUI Builder tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
4,600+ MCP servers and 31,000+ tools scanned and risk-classified.