btc_sign_message · Bitcoin wallet MCP server MCP

WHAT IT DOES

What btc_sign_message does on Bitcoin wallet MCP server

AI agents invoke btc_sign_message to trigger actions in Bitcoin wallet MCP server. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why btc_sign_message needs a policy

Signing a message with a wallet key is an execution of a cryptographic operation using sensitive private key material. It does not directly move funds (Financial) or delete data (Destructive), but it can be misused to authenticate transactions or prove identity, making it a meaningful security operation. It is more than a passive Read since it actively uses the private key.

From the tool's definition 'Sign a message using the wallet' — uses wallet cryptographic keys to produce a signature

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

btc_sign_message Rate-limited

btc_sign_message stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "btc_sign_message": {
      "limits": [
        {
          "counter": "btc_sign_message_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Bitcoin wallet MCP server, so you can run agents against it safely.

FAQ

Questions about btc_sign_message

What does the btc_sign_message tool do? +

Sign a message using the wallet. It is categorised as a Execute tool in the Bitcoin wallet MCP server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on btc_sign_message? +

Register the Bitcoin wallet MCP server MCP server in PolicyLayer and add a rule for btc_sign_message: 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.

What risk level is btc_sign_message? +

btc_sign_message is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit btc_sign_message? +

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

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

btc_sign_message 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.