AI agents call finance_forex_rate to retrieve information from Data Apis without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This is a pure data retrieval operation with no side effects. It queries and returns historical FX rate information without modifying, executing, or destroying anything. The financial context (forex rates) does not make it a Financial category tool—that category requires moving money or committing financial obligations. The $0.01 micropayment is a usage cost, not a financial transaction performed by the tool itself.
From the tool's definition Tool retrieves foreign exchange rates and 5-day history between two currencies. Description explicitly states it 'Get[s]' data with no modification, creation, deletion, or code execution capabilities. Format shows simple currency pair queries (e.g., USD-EUR).
Attacks that exploit this kind of access
Get foreign exchange rate between two currencies with 5-day history. Costs $0.01 USDC per request via x402 on Base. Format: FROM-TO (e.g., USD-EUR, GBP-JPY, EUR-INR). It is categorised as a Read tool in the Data Apis MCP Server, which means it retrieves data without modifying state.
Register the Data Apis MCP server in PolicyLayer and add a rule for finance_forex_rate: 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 Data Apis. Nothing to install.
finance_forex_rate is a Read tool with low risk. Read-only tools are generally safe to allow by default.
Yes. Add a rate_limit block to the finance_forex_rate 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.
Set action: deny in the PolicyLayer policy for finance_forex_rate. 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.
finance_forex_rate is provided by the Data Apis MCP server (yantrix-ai/x402-apis-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Every MCP server has a record like this.
Type a name, get the same breakdown: verified identity, auth posture, risk grade, capabilities, recommended policy.
Teams ship this data inside their own products. See what a licence covers →