duplicate_invoice · FacturaHub MCP Server MCP: Risk & Policy

WHAT IT DOES

What duplicate_invoice does on FacturaHub MCP Server

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

WHY IT NEEDS A POLICY

Why duplicate_invoice needs a policy

This tool creates new invoice records in the accounting system, which constitutes a Write operation. While invoices are financially significant, the tool itself does not transfer money or commit financial obligations—it only duplicates existing billing records with updated timestamps. This is reversible, distinguishing it from Destructive.

From the tool's definition Tool description states 'Create a copy of an existing FacturaHub invoice with a new date,' which creates new financial records. The operation is reversible (invoices can be deleted or marked void) and does not irreversibly destroy data.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

duplicate_invoice Rate-limited

duplicate_invoice 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": {
    "duplicate_invoice": {
      "limits": [
        {
          "counter": "duplicate_invoice_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 FacturaHub MCP Server, so you can run agents against it safely.

FAQ

Questions about duplicate_invoice

What does the duplicate_invoice tool do? +

[FacturaHub] Create a copy of an existing FacturaHub invoice with a new date. Useful for recurring billing. It is categorised as a Write tool in the FacturaHub MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on duplicate_invoice? +

Register the FacturaHub MCP Server MCP server in PolicyLayer and add a rule for duplicate_invoice: 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 FacturaHub MCP Server. Nothing to install.

What risk level is duplicate_invoice? +

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

Can I rate-limit duplicate_invoice? +

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

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

duplicate_invoice is provided by the FacturaHub MCP Server MCP server (santy1422/facturahub-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.