Returns a mapping of all supported fiat currencies to unique CoinMarketCap IDs.
AI agents call fiatMap to retrieve information from CoinMarketCap MCP without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool queries and retrieves static reference data (fiat currency mappings). It performs no writes, deletes, executions, or financial transactions. The low severity reflects that misuse would only expose informational data with no blast radius for system integrity or user assets.
From the tool's definition Tool description states it 'Returns a mapping of all supported fiat currencies to unique CoinMarketCap IDs' — a pure data retrieval operation with no mutation, deletion, or side effects.
Documented attack patterns abuse exactly the kind of access fiatMap gives an agent:
PolicyLayer is an MCP gateway — it sits between your AI agents and CoinMarketCap MCP, and nothing reaches the server without passing your rules. This is the rule we recommend for fiatMap:
{
"version": "1",
"default": "deny",
"tools": {
"fiatMap": {}
}
}fiatMap is read-only, so it stays allowed — but everything else on the server is denied unless you say otherwise.
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Returns a mapping of all supported fiat currencies to unique CoinMarketCap IDs. It is categorised as a Read tool in the CoinMarketCap MCP MCP Server, which means it retrieves data without modifying state.
Register the CoinMarketCap MCP server in PolicyLayer and add a rule for fiatMap: 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 CoinMarketCap MCP. Nothing to install.
fiatMap 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 fiatMap 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 fiatMap. 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.
fiatMap is provided by the CoinMarketCap MCP server (shinzo-labs/coinmarketcap-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.
Deterministic rules across all 51 CoinMarketCap MCP tools. Per-identity grants. Full audit log. Live in minutes. Nothing to install.
Free to start. No card required.
51 CoinMarketCap MCP tools catalogued and risk-classified — across an index of 42,500+ MCP servers.