write-contract · MCPilot MCP: Risk & Policy

WHAT IT DOES

What write-contract does on MCPilot

AI agents use write-contract to create or update resources in MCPilot — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your MCPilot environment.

WHY IT NEEDS A POLICY

Why write-contract needs a policy

An AI agent can call write-contract faster than any human can review — one bad instruction and it creates or modifies resources in MCPilot by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

write-contract Rate-limited

write-contract stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "write-contract": {
      "limits": [
        {
          "counter": "write-contract_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about write-contract

What does the write-contract tool do? +

Execute a write function on a contract. It is categorised as a Write tool in the MCPilot MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on write-contract? +

Register the MCPilot MCP server in PolicyLayer and add a rule for write-contract: 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 MCPilot. Nothing to install.

What risk level is write-contract? +

write-contract is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit write-contract? +

Yes. Add a rate_limit block to the write-contract 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 write-contract completely? +

Set action: deny in the PolicyLayer policy for write-contract. 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 write-contract? +

write-contract is provided by the MCPilot MCP server (xiawpohr/mcpilot). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.