set_wallet_mode · Justlend MCP: Risk & Policy

WHAT IT DOES

What set_wallet_mode does on Justlend

AI agents use set_wallet_mode 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 set_wallet_mode needs a policy

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

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_wallet_mode Rate-limited

set_wallet_mode 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": {
    "set_wallet_mode": {
      "limits": [
        {
          "counter": "set_wallet_mode_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 set_wallet_mode

What does the set_wallet_mode tool do? +

Switch wallet signing mode. 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 set_wallet_mode? +

Register the Justlend MCP server in PolicyLayer and add a rule for set_wallet_mode: 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 set_wallet_mode? +

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

Can I rate-limit set_wallet_mode? +

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

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

set_wallet_mode 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.