rbac_reject_request · n8n Workflow Builder MCP

WHAT IT DOES

What rbac_reject_request does on n8n Workflow Builder

AI agents use rbac_reject_request to create or update resources in n8n Workflow Builder — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your n8n Workflow Builder environment.

WHY IT NEEDS A POLICY

Why rbac_reject_request needs a policy

This tool modifies workflow approval request state, fitting the Write category (reversible modification of data). Severity is medium because rejection affects workflow governance and could impact business processes, but the action is reversible (the request could theoretically be resubmitted or reviewed again).

From the tool's definition Tool name 'rbac_reject_request' with description 'Reject a pending approval request' indicates modifying the state of an approval request from pending to rejected, which is a reversible change to workflow state/data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

rbac_reject_request Rate-limited

rbac_reject_request 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": {
    "rbac_reject_request": {
      "limits": [
        {
          "counter": "rbac_reject_request_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches n8n Workflow Builder, so you can run agents against it safely.

FAQ

Questions about rbac_reject_request

What does the rbac_reject_request tool do? +

❌ Reject a pending approval request. It is categorised as a Write tool in the n8n Workflow Builder MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on rbac_reject_request? +

Register the n8n Workflow Builder MCP server in PolicyLayer and add a rule for rbac_reject_request: 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 n8n Workflow Builder. Nothing to install.

What risk level is rbac_reject_request? +

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

Can I rate-limit rbac_reject_request? +

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

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

rbac_reject_request is provided by the n8n Workflow Builder MCP server (schimmilab/n8n-workflow-builder). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.