list_currencies

Get a list of all currencies with ISO codes, symbols, and country usage. Parameters: (no parameters needed)

SERVERX402 Middleware SOURCE@gadgethumans/x402

Low RISK CLASS

Category Read

Parameters 00 required

Recommended Allowedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/com-gadgethumans-swarm-x402-middleware/list-currencies.md

WHAT IT DOES

What list_currencies does on X402 Middleware

AI agents call list_currencies to retrieve information from X402 Middleware without modifying anything. It is typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.

RISK

Why list_currencies is rated Low

This tool queries static currency reference information with no side effects, no financial transactions, and no ability to modify or delete data. It is a straightforward data retrieval operation, making it a Read category tool with low severity risk.

From the tool's definition Tool name 'list_currencies' and description 'Get a list of all currencies' indicate a retrieval operation that returns reference data (ISO codes, symbols, country usage) without modifying state.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs list_currencies safely

PolicyLayer is an MCP gateway: it sits between your AI agents and X402 Middleware, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For list_currencies, this is the rule to start with:

list_currencies Allowed

list_currencies 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": {
    "list_currencies": {}
  }
}

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

The button opens the PolicyLayer dashboard: create your workspace, connect X402 Middleware, apply this rule, and every list_currencies call is checked against it from then on.

FAQ

Questions about list_currencies

What does the list_currencies tool do? +

Get a list of all currencies with ISO codes, symbols, and country usage. Parameters: (no parameters needed). It is categorised as a Read tool in the X402 Middleware MCP Server, which means it retrieves data without modifying state.

How do I enforce a policy on list_currencies? +

Register the X402 Middleware MCP server in PolicyLayer and add a rule for list_currencies: 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 X402 Middleware. Nothing to install.

What risk level is list_currencies? +

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

Can I rate-limit list_currencies? +

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

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

list_currencies is provided by the X402 Middleware MCP server (@gadgethumans/x402). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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