Get recommended fee rates from mempool.space for all tiers:
AI agents call btc_get_fees to retrieve information from Bitcoin wallet MCP server without modifying anything — typically the context-gathering step in research, monitoring, and reporting workflows, before the agent takes action elsewhere.
This tool retrieves fee rate data from an external service (mempool.space) without side effects. It does not send funds, modify wallet state, or execute transactions. It is a pure read operation that provides informational data to support transaction planning. Severity is low because misuse cannot cause financial loss or data damage on its own.
From the tool's definition Tool name 'btc_get_fees' and description 'Get recommended fee rates from mempool.space for all tiers' indicate data retrieval only. No modification, deletion, or financial transaction occurs—only querying public fee rate information.
Attacks that exploit this kind of access
Get recommended fee rates from mempool.space for all tiers:. It is categorised as a Read tool in the Bitcoin wallet MCP server MCP Server, which means it retrieves data without modifying state.
Register the Bitcoin wallet MCP server MCP server in PolicyLayer and add a rule for btc_get_fees: 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 Bitcoin wallet MCP server. Nothing to install.
btc_get_fees 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 btc_get_fees 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 btc_get_fees. 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.
btc_get_fees is provided by the Bitcoin wallet MCP server MCP server (markmhendrickson/mcp-server-bitcoin). 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.
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