mqtt_publish_sync · MCP API Bridge Server MCP: Risk & Policy

WHAT IT DOES

What mqtt_publish_sync does on MCP API Bridge Server

AI agents invoke mqtt_publish_sync to trigger actions in MCP API Bridge Server. 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 mqtt_publish_sync needs a policy

This tool publishes MQTT messages to IoT devices and waits for a response, triggering external operations on IoT infrastructure. The effects depend on the message payload and target topic — it could command physical devices to change state, actuate hardware, or trigger automation workflows.

From the tool's definition 同步發布 MQTT 訊息並等待回應 (Synchronously publish MQTT messages and wait for response)

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

mqtt_publish_sync Rate-limited

mqtt_publish_sync 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": {
    "mqtt_publish_sync": {
      "limits": [
        {
          "counter": "mqtt_publish_sync_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 MCP API Bridge Server, so you can run agents against it safely.

FAQ

Questions about mqtt_publish_sync

What does the mqtt_publish_sync tool do? +

同步發布 MQTT 訊息並等待回應. It is categorised as a Execute tool in the MCP API Bridge Server MCP Server, which means it can trigger actions or run processes. Use rate limits and argument validation.

How do I enforce a policy on mqtt_publish_sync? +

Register the MCP API Bridge Server MCP server in PolicyLayer and add a rule for mqtt_publish_sync: 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 MCP API Bridge Server. Nothing to install.

What risk level is mqtt_publish_sync? +

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

Can I rate-limit mqtt_publish_sync? +

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

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

mqtt_publish_sync is provided by the MCP API Bridge Server MCP server (marty5499/mcp-api-bridge). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.