ugf_set_token · Universal Gas Framework MCP Server MCP

WHAT IT DOES

What ugf_set_token does on Universal Gas Framework MCP Server

AI agents use ugf_set_token to create or update resources in Universal Gas Framework MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Universal Gas Framework MCP Server environment.

WHY IT NEEDS A POLICY

Why ugf_set_token needs a policy

This tool modifies client-side authentication state by caching a JWT token. While it doesn't create or delete transactions directly, it establishes or updates a stored credential that controls authorization for subsequent financial operations (gasless token swaps across chains). The severity is high because compromised JWT caching could enable unauthorized transaction execution.

From the tool's definition Tool description states 'Restore a cached UGF JWT on the MCP client', which involves storing/modifying authentication state. The JWT is a security credential used for transaction authorization in a gasless cross-chain framework.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

ugf_set_token Rate-limited

ugf_set_token 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": {
    "ugf_set_token": {
      "limits": [
        {
          "counter": "ugf_set_token_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 Universal Gas Framework MCP Server, so you can run agents against it safely.

FAQ

Questions about ugf_set_token

What does the ugf_set_token tool do? +

Restore a cached UGF JWT on the MCP client. Use this on subsequent sessions to skip re-signing the nonce. It is categorised as a Write tool in the Universal Gas Framework MCP Server MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on ugf_set_token? +

Register the Universal Gas Framework MCP Server MCP server in PolicyLayer and add a rule for ugf_set_token: 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 Universal Gas Framework MCP Server. Nothing to install.

What risk level is ugf_set_token? +

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

Can I rate-limit ugf_set_token? +

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

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

ugf_set_token is provided by the Universal Gas Framework MCP Server MCP server (tychiwallet/ugf-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.