secp256k1_sign · Privy MCP Server MCP: Risk & Policy

WHAT IT DOES

What secp256k1_sign does on Privy MCP Server

AI agents invoke secp256k1_sign to trigger actions in Privy 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 secp256k1_sign needs a policy

Cryptographic signing with secp256k1 is a core blockchain operation that authorizes transactions and messages. While not directly moving funds, signing is the critical step that enables financial transactions to be authorized and broadcast. It triggers an external cryptographic operation whose effects depend on what hash is being signed.

From the tool's definition Sign a hash using the secp256k1 method

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

secp256k1_sign Rate-limited

secp256k1_sign 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": {
    "secp256k1_sign": {
      "limits": [
        {
          "counter": "secp256k1_sign_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 Privy MCP Server, so you can run agents against it safely.

FAQ

Questions about secp256k1_sign

What does the secp256k1_sign tool do? +

Sign a hash using the secp256k1 method. It is categorised as a Execute tool in the Privy 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 secp256k1_sign? +

Register the Privy MCP Server MCP server in PolicyLayer and add a rule for secp256k1_sign: 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 Privy MCP Server. Nothing to install.

What risk level is secp256k1_sign? +

secp256k1_sign is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit secp256k1_sign? +

Yes. Add a rate_limit block to the secp256k1_sign 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 secp256k1_sign completely? +

Set action: deny in the PolicyLayer policy for secp256k1_sign. 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 secp256k1_sign? +

secp256k1_sign is provided by the Privy MCP Server MCP server (privy-io/privy-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.