credential_create · N8n Fabric MCP: Risk & Policy

WHAT IT DOES

What credential_create does on N8n Fabric

AI agents use credential_create to create or update resources in N8n Fabric — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your N8n Fabric environment.

WHY IT NEEDS A POLICY

Why credential_create needs a policy

This is a Write operation as it creates new data (credentials) that persists in the system. Severity is high because credentials are security-sensitive; an attacker could create malicious credentials to compromise workflow execution, enable unauthorized access to external systems, or pivot to other integrated services.

From the tool's definition Tool name 'credential_create' combined with description 'Create a new credential' indicates this tool creates and stores credentials (authentication tokens, API keys, passwords, etc.) in n8n's credential system.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

credential_create Rate-limited

credential_create 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": {
    "credential_create": {
      "limits": [
        {
          "counter": "credential_create_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 Fabric, so you can run agents against it safely.

FAQ

Questions about credential_create

What does the credential_create tool do? +

Create a new credential. It is categorised as a Write tool in the N8n Fabric MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on credential_create? +

Register the N8n Fabric MCP server in PolicyLayer and add a rule for credential_create: 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 Fabric. Nothing to install.

What risk level is credential_create? +

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

Can I rate-limit credential_create? +

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

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

credential_create is provided by the N8n Fabric MCP server (ry-ops/n8n-fabric). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.