x402_send_email

Server x402 MCP Server jameswilliamwisdom/x402-mcp-server

Category Write

Risk class Medium

Parameters 00 required

WHAT IT DOES

What x402_send_email does on x402 MCP Server

AI agents use x402_send_email to create or update resources in x402 MCP Server — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your x402 MCP Server environment.

WHY IT NEEDS A POLICY

Why x402_send_email needs a policy

An AI agent can call x402_send_email faster than any human can review — one bad instruction and it creates or modifies resources in x402 MCP Server by the hundred, each call as confident as the last.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

x402_send_email Rate-limited

x402_send_email 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": {
    "x402_send_email": {
      "limits": [
        {
          "counter": "x402_send_email_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 x402 MCP Server, so you can run agents against it safely.

FAQ

Questions about x402_send_email

What does the x402_send_email tool do? +

Send a transactional email via Resend. Price: $0.01 USDC per email (paid mode) | Free test: returns fixture data. Supports plain text or HTML body, CC/BCC recipients, and file attachments (base64-encoded, max 25MB per file). Per-wallet daily limit: 10 emails. Per-domain daily limit: 5 emails (applies to all recipients including CC/BCC). Without X402_PRIVATE_KEY, only the free test endpoint is available. Returns: message_id from Resend. It is categorised as a Write tool in the x402 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 x402_send_email? +

Register the x402 MCP Server MCP server in PolicyLayer and add a rule for x402_send_email: 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 x402 MCP Server. Nothing to install.

What risk level is x402_send_email? +

x402_send_email is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit x402_send_email? +

Yes. Add a rate_limit block to the x402_send_email 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 x402_send_email completely? +

Set action: deny in the PolicyLayer policy for x402_send_email. 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 x402_send_email? +

x402_send_email is provided by the x402 MCP Server MCP server (jameswilliamwisdom/x402-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.