luhn

Luhn Checksum (validate / check digit) — Validate a Luhn number (cards, IMEI) or compute its check digit. Formula only — not card validity.

SERVERGateway SOURCEhttps://wingmanprotocol.com/mcp

Low RISK CLASS

Category Read

Parameters 21 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/com-wingmanprotocol-agent-gateway/luhn.md

WHAT IT DOES

What luhn does on Gateway

AI agents call luhn to retrieve information from Gateway without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

Parameter	Type	Required	Description
`mode`	string	—	Operation
`number`	string	Yes	Number to check (non-digits ignored)

Parameters from the server's own tool schema.

RISK

Why luhn is rated Low

The Luhn algorithm is a pure checksum validation function. It reads input data (a number), applies a mathematical formula, and returns a result without side effects, data modification, or external operations. The explicit note 'Formula only' confirms it does not perform actual card validation or financial transactions.

From the tool's definition Tool description states 'Validate a Luhn number' and 'compute its check digit' with explicit clarification 'Formula only — not card validity'.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs luhn safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Gateway, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For luhn, this is the rule to start with:

luhn Allowed

luhn is read-only, so it stays allowed. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "luhn": {}
  }
}

ALLOW ONLY THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Gateway, apply this rule, and every luhn call is checked against it from then on.

FAQ

Questions about luhn

What does the luhn tool do? +

Luhn Checksum (validate / check digit) — Validate a Luhn number (cards, IMEI) or compute its check digit. Formula only — not card validity. It is categorised as a Read tool in the Gateway MCP Server, which means it retrieves data without modifying state.

What parameters does luhn accept? +

luhn accepts 2 parameters: mode, number. Required: number. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on luhn? +

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

What risk level is luhn? +

luhn is a Read tool with low risk. Read-only tools are generally safe to allow by default.

Can I rate-limit luhn? +

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

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

luhn is provided by the Gateway MCP server (https://wingmanprotocol.com/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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