start_anvil_with_options · Foundry MCP Project MCP

WHAT IT DOES

What start_anvil_with_options does on Foundry MCP Project

AI agents invoke start_anvil_with_options to trigger actions in Foundry MCP Project. 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 start_anvil_with_options needs a policy

This tool starts a local Ethereum blockchain node (Anvil), which is an Execute category action as it launches and manages an external service whose behavior depends on provided options. While not destructive or financial by itself, misuse could enable subsequent financial transactions on the test node or lock system resources.

From the tool's definition Tool name 'start_anvil_with_options' indicates launching Anvil (Foundry's local Ethereum test node). The sibling tools include 'run_script', 'run_cast_command_with_options', and 'start_chisel_with_options', establishing this server's pattern of executing…

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

start_anvil_with_options Rate-limited

start_anvil_with_options 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": {
    "start_anvil_with_options": {
      "limits": [
        {
          "counter": "start_anvil_with_options_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 Foundry MCP Project, so you can run agents against it safely.

FAQ

Questions about start_anvil_with_options

What does the start_anvil_with_options tool do? +

start_anvil_with_options. It is categorised as a Execute tool in the Foundry MCP Project MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on start_anvil_with_options? +

Register the Foundry MCP Project MCP server in PolicyLayer and add a rule for start_anvil_with_options: 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 Foundry MCP Project. Nothing to install.

What risk level is start_anvil_with_options? +

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

Can I rate-limit start_anvil_with_options? +

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

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

start_anvil_with_options is provided by the Foundry MCP Project MCP server (lhemerly/foundry-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.