tx_submit_signed · Xrpl Identity MCP: Risk & Policy

WHAT IT DOES

What tx_submit_signed does on Xrpl Identity

AI agents invoke tx_submit_signed to trigger actions in Xrpl Identity. What it does depends on the arguments the agent supplies, and its effects often reach beyond the immediate call — builds kicked off, notifications sent, workflows started.

WHY IT NEEDS A POLICY

Why tx_submit_signed needs a policy

This tool submits signed transactions to the XRP Ledger blockchain, causing irreversible on-chain state changes (DIDs, credentials, signer lists). While it doesn't custody keys, submitting a signed blob executes real blockchain transactions with permanent effects. It spans Execute and potentially Destructive/Financial depending on the transaction type, but the tool itself is a general submission mechanism.

From the tool's definition 'Submit a pre-signed XRPL transaction blob and poll for validation' — triggers external on-chain operations on the XRP Ledger

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

tx_submit_signed Rate-limited

tx_submit_signed stays usable, but rate-capped — a runaway agent can't fire it dozens of times a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "tx_submit_signed": {
      "limits": [
        {
          "counter": "tx_submit_signed_rate",
          "window": "minute",
          "max": 10,
          "scope": "grant"
        }
      ]
    }
  }
}

RATE-LIMIT THIS TOOL →

Instant setup, no code required.

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

FAQ

Questions about tx_submit_signed

What does the tx_submit_signed tool do? +

Submit a pre-signed XRPL transaction blob and poll for validation. On mainnet this is blocked unless ALLOW_MAINNET_SUBMIT=true is set. It is categorised as a Execute tool in the Xrpl Identity MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on tx_submit_signed? +

Register the Xrpl Identity MCP server in PolicyLayer and add a rule for tx_submit_signed: 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 Xrpl Identity. Nothing to install.

What risk level is tx_submit_signed? +

tx_submit_signed is a Execute tool with high risk. Execute tools should be rate-limited and have argument validation enabled.

Can I rate-limit tx_submit_signed? +

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

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

tx_submit_signed is provided by the Xrpl Identity MCP server (jarod-vyent/xrpl-identity-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.