prepareTransaction

Prepare a basic ETH transfer transaction for signing. Returns transaction data that can be signed and broadcast.

SERVERMCP Ethers Wallet SOURCEcrazyrabbitltc/mcp-ethers-server

Critical RISK CLASS

Category Financial

Parameters 00 required

Recommended Approval-gatedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/crazyrabbitltc-mcp-ethers-server/preparetransaction.md

WHAT IT DOES

What prepareTransaction does on MCP Ethers Wallet

AI agents use prepareTransaction to commit financial operations through MCP Ethers Wallet, usually the final step of a payment, billing, or trading workflow. A call moves real money.

RISK

Why prepareTransaction is rated Critical

This tool prepares an ETH transfer transaction, which directly facilitates the movement of financial value (Ether) on the Ethereum network. Even though it only prepares/returns transaction data rather than executing it outright, the output is intended to be signed and broadcast, making it a precursor step in a financial transaction flow.

From the tool's definition Prepare a basic ETH transfer transaction for signing. Returns transaction data that can be signed and broadcast.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs prepareTransaction safely

PolicyLayer is an MCP gateway: it sits between your AI agents and MCP Ethers Wallet, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For prepareTransaction, this is the rule to start with:

prepareTransaction Approval-gated

Any call to prepareTransaction is blocked until a human approves it. The rest of the server keeps working.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "prepareTransaction": {
      "deny_if": [
        {
          "conditions": [],
          "on_deny": "Requires human approval."
        }
      ]
    }
  }
}

GATE THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect MCP Ethers Wallet, apply this rule, and every prepareTransaction call is checked against it from then on.

FAQ

Questions about prepareTransaction

What does the prepareTransaction tool do? +

Prepare a basic ETH transfer transaction for signing. Returns transaction data that can be signed and broadcast. It is categorised as a Financial tool in the MCP Ethers Wallet MCP Server, which means it involves financial transactions. Block by default and require explicit approval.

How do I enforce a policy on prepareTransaction? +

Register the MCP Ethers Wallet MCP server in PolicyLayer and add a rule for prepareTransaction: 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 MCP Ethers Wallet. Nothing to install.

What risk level is prepareTransaction? +

prepareTransaction is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit prepareTransaction? +

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

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

prepareTransaction is provided by the MCP Ethers Wallet MCP server (crazyrabbitltc/mcp-ethers-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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