whmcs_add_payment

THE RISK

Critical Risk

Why whmcs_add_payment needs a policy

This tool records a payment against an invoice, which is a financial operation that commits financial records. It could be misused to falsely mark invoices as paid or record fraudulent payments, making it a Financial category tool with high severity.

From the tool's definition Record a payment on an invoice

Documented attack patterns abuse exactly the kind of access whmcs_add_payment gives an agent:

POLICY

How to control whmcs_add_payment

PolicyLayer is an MCP gateway — it sits between your AI agents and Whmcs, and nothing reaches the server without passing your rules. This is the rule we recommend for whmcs_add_payment:

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "whmcs_add_payment": {
      "deny_if": [
        {
          "conditions": [],
          "on_deny": "Requires human approval."
        }
      ]
    }
  }
}

Any call to whmcs_add_payment is blocked until a human approves it. The rest of the server keeps working.

Create a free account and register Whmcs — nothing to install.
Add this policy — paste it, or build it visually.
Point your MCP client (Claude, Cursor, anything) at your gateway URL.

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EXPLORE

Related tools and policies

More Whmcs tools

Financial whmcs_accept_quote Accept a quote and convert to invoice Financial whmcs_register_domain Send domain registration command to registrar Financial whmcs_renew_domain Send domain renewal command to registrar Destructive whmcs_cancel_order Cancel an order Destructive whmcs_delete_client Delete a client from WHMCS (use with caution) Destructive whmcs_delete_order Delete an order (use with caution) Destructive whmcs_delete_quote Delete a quote Destructive whmcs_delete_ticket Delete a support ticket (use with caution)

All 62 Whmcs tools →

Financial tools on other servers

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Go deeper

Critical-risk tools in Whmcs → Every critical-risk tool this server exposes, in one view.
All critical-risk MCP tools → Every critical-risk tool across the catalogue, and the policy pattern that contains them.
The MCP Attack Database → Documented attack patterns against MCP deployments — and the policies that stop them.
Human-in-the-loop → When a tool call should wait for a person — and when policy can decide alone.
Tool call approval → Approval gates on individual tool calls: auto-allow, prompt, or deny.
How to Add Spending Controls to Any MCP Agent →
Rate Limiting MCP Tool Calls: A Practical Guide →

FAQ

Questions about whmcs_add_payment

What does the whmcs_add_payment tool do? +

Record a payment on an invoice. It is categorised as a Financial tool in the Whmcs MCP Server, which means it involves financial transactions. Block by default and require explicit approval.

How do I enforce a policy on whmcs_add_payment? +

Register the Whmcs MCP server in PolicyLayer and add a rule for whmcs_add_payment: 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 Whmcs. Nothing to install.

What risk level is whmcs_add_payment? +

whmcs_add_payment is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit whmcs_add_payment? +

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

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

whmcs_add_payment is provided by the Whmcs MCP server (scarecr0w12/whmcs-mcp-tool). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

Enforce policy on every Whmcs tool call.

Start from Whmcs, add the rest of your stack, and see everything your agents can call. Then put policy on all of it.

CHECK YOUR STACK →