approve_moolah_proxy · Justlend MCP: Risk & Policy

WHAT IT DOES

What approve_moolah_proxy does on Justlend

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

WHY IT NEEDS A POLICY

Why approve_moolah_proxy needs a policy

The tool performs token approval operations, which are write operations that modify blockchain state by granting spending permissions to a contract. While reversible (approvals can be changed), this is a critical financial operation in a lending protocol context. Classified as Write rather than Financial because the tool itself grants permissions rather than directly moving funds or committing financial obligations.

From the tool's definition Tool description explicitly states 'Approve TRC20 token spending' which involves modifying token allowances/approvals on a blockchain contract. This is a state-changing operation that alters the permissions granted to the Moolah core contract.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

approve_moolah_proxy Rate-limited

approve_moolah_proxy 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": {
    "approve_moolah_proxy": {
      "limits": [
        {
          "counter": "approve_moolah_proxy_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 Justlend, so you can run agents against it safely.

FAQ

Questions about approve_moolah_proxy

What does the approve_moolah_proxy tool do? +

Approve TRC20 token spending for the Moolah core contract before supplying collateral or repaying. It is categorised as a Write tool in the Justlend MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on approve_moolah_proxy? +

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

What risk level is approve_moolah_proxy? +

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

Can I rate-limit approve_moolah_proxy? +

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

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

approve_moolah_proxy is provided by the Justlend MCP server (justlend/mcp-server-justlend). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.