send_transaction · Flow MCP Server MCP: Risk & Policy

WHAT IT DOES

What send_transaction does on Flow MCP Server

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

WHY IT NEEDS A POLICY

Why send_transaction needs a policy

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

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

send_transaction Rate-limited

send_transaction 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": {
    "send_transaction": {
      "limits": [
        {
          "counter": "send_transaction_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 Flow MCP Server, so you can run agents against it safely.

FAQ

Questions about send_transaction

What does the send_transaction tool do? +

Send a transaction to the blockchain. It is categorised as a Write tool in the Flow 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 send_transaction? +

Register the Flow MCP Server MCP server in PolicyLayer and add a rule for send_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 Flow MCP Server. Nothing to install.

What risk level is send_transaction? +

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

Can I rate-limit send_transaction? +

Yes. Add a rate_limit block to the send_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 send_transaction completely? +

Set action: deny in the PolicyLayer policy for send_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 send_transaction? +

send_transaction is provided by the Flow MCP Server MCP server (lmcmz/flow-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

// THE FULL RECORD

send_transaction is one line of Flow MCP Server's registry record.

The record carries the whole server: verified identity, auth posture, risk grade, every tool classified, recommended policy — re-checked continuously.

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