prepare_weth_unwrap

SERVERVaultPilot MCP SOURCEvaultpilot-mcp

High RISK CLASS

Category Execute

Parameters 32 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-szhygulin-vaultpilot-mcp/prepare-weth-unwrap.md

WHAT IT DOES

What prepare_weth_unwrap does on VaultPilot MCP

AI agents invoke prepare_weth_unwrap to trigger actions in VaultPilot MCP. 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.

Parameter	Type	Required	Description
`chain`	string	—
`amount`	string	Yes	Human-readable WETH amount, NOT raw wei. Example: "0.5" for 0.5 WETH. Pass "max" to unwrap the full WETH balance. WETH is always 18 decimals on every supported
`wallet`	string	Yes

Parameters from the server's own tool schema.

RISK

Why prepare_weth_unwrap is rated High

This tool constructs and triggers an on-chain smart contract call (WETH.withdraw) that burns WETH tokens and returns native ETH. While it only 'prepares' an unsigned transaction, it involves executing a DeFi contract interaction that converts crypto assets.

From the tool's definition Build an unsigned WETH → native ETH unwrap transaction via a direct `WETH.withdraw(uint256)` call on the canonical WETH9 contract

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs prepare_weth_unwrap safely

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

prepare_weth_unwrap Rate-limited

prepare_weth_unwrap 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": {
    "prepare_weth_unwrap": {
      "limits": [
        {
          "counter": "prepare_weth_unwrap_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL → Instant setup, no code required.

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

FAQ

Questions about prepare_weth_unwrap

What does the prepare_weth_unwrap tool do? +

Build an unsigned WETH → native ETH unwrap transaction via a direct WETH.withdraw(uint256) call on the canonical WETH9 contract for the target chain. Supported chains: ethereum, arbitrum, polygon, base, optimism. Pass an explicit decimal amount (e.g. "0.5") or the literal "max" to unwrap the full WETH balance. WETH is always 18 decimals. No approval is required — the wallet burns its own balance and receives native ETH back in the same call; the call is cheaper than routing through a DEX/aggregator. Balance is checked pre-build and the call refuses with a clear message if the wallet is short, rather than letting the tx revert on-chain. For the symmetric wrap direction (native ETH → WETH), use prepare_native_send with the WETH contract as to — sending ETH to the WETH9 fallback triggers deposit() automatically. It is categorised as a Execute tool in the VaultPilot MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

What parameters does prepare_weth_unwrap accept? +

prepare_weth_unwrap accepts 3 parameters: chain, amount, wallet. Required: amount, wallet. The full parameter table on this page comes from the server's own tool schema.

How do I enforce a policy on prepare_weth_unwrap? +

Register the VaultPilot MCP server in PolicyLayer and add a rule for prepare_weth_unwrap: 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 VaultPilot MCP. Nothing to install.

What risk level is prepare_weth_unwrap? +

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

Can I rate-limit prepare_weth_unwrap? +

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

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

prepare_weth_unwrap is provided by the VaultPilot MCP server (vaultpilot-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

KEEP EXPLORING

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