happy_send_message · Happy Server MCP: Risk & Policy

WHAT IT DOES

What happy_send_message does on Happy Server MCP

AI agents invoke happy_send_message to trigger actions in Happy Server MCP. 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 happy_send_message needs a policy

This tool sends a message that triggers an AI coding session to perform work, with 'bypass permissions mode' — meaning it can cause the AI agent to execute actions (write files, run code, etc.) potentially without normal permission checks. The bypass permissions aspect significantly elevates risk, as a misuse could cause the AI to perform privileged operations.

From the tool's definition 'Send a message to a Happy AI session to trigger it to work. The message will be sent with bypass permissions mode.'

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

happy_send_message Rate-limited

happy_send_message 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": {
    "happy_send_message": {
      "limits": [
        {
          "counter": "happy_send_message_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 Happy Server MCP, so you can run agents against it safely.

FAQ

Questions about happy_send_message

What does the happy_send_message tool do? +

Send a message to a Happy AI session to trigger it to work. The message will be sent with bypass permissions mode. It is categorised as a Execute tool in the Happy Server MCP MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on happy_send_message? +

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

What risk level is happy_send_message? +

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

Can I rate-limit happy_send_message? +

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

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

happy_send_message is provided by the Happy Server MCP server (zhigang1992/happy-server-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.