sponsor_transaction · Tenzro Ledger MCP: Risk & Policy

WHAT IT DOES

What sponsor_transaction does on Tenzro Ledger MCP

AI agents use sponsor_transaction to commit financial operations through Tenzro Ledger MCP — usually the final step of a payment, billing, or trading workflow. A call moves real money.

WHY IT NEEDS A POLICY

Why sponsor_transaction needs a policy

This tool commits financial resources by paying gas fees on behalf of a user via a paymaster, which constitutes a financial obligation/expenditure. Misuse could drain funds from the sponsoring account by triggering arbitrary sponsored transactions.

From the tool's definition Sponsor a transaction for a user (app pays gas via paymaster)

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

sponsor_transaction Approval-gated

Any call to sponsor_transaction is blocked until a human approves it. The rest of the server keeps working.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "sponsor_transaction": {
      "deny_if": [
        {
          "conditions": [],
          "on_deny": "Requires human approval."
        }
      ]
    }
  }
}

GATE THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about sponsor_transaction

What does the sponsor_transaction tool do? +

Sponsor a transaction for a user (app pays gas via paymaster). It is categorised as a Financial tool in the Tenzro Ledger MCP MCP Server, which means it involves financial transactions. Block by default and require explicit approval.

How do I enforce a policy on sponsor_transaction? +

Register the Tenzro Ledger MCP server in PolicyLayer and add a rule for sponsor_transaction: 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 Tenzro Ledger MCP. Nothing to install.

What risk level is sponsor_transaction? +

sponsor_transaction is a Financial tool with critical risk. Critical-risk tools should be blocked by default and only enabled with explicit human approval.

Can I rate-limit sponsor_transaction? +

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

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

sponsor_transaction is provided by the Tenzro Ledger MCP server (https://canton-mcp.tenzro.network/mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.