sendMessage

Send a message to the live chat run

SERVERNodebench SOURCEnodebench-mcp

Medium RISK CLASS

Category Write

Parameters 00 required

Recommended Rate-limitedsee the rule below

Registry record Grade F, identity unverified Pull the record →

This record as markdown: /tools/io-github-homenshum-nodebench/sendmessage.md

WHAT IT DOES

What sendMessage does on Nodebench

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

RISK

Why sendMessage is rated Medium

This tool creates new message records in a live chat, which is a reversible Write operation. Severity is medium because misuse could spam chat, disrupt communications, or inject unwanted messages into a live session, but the blast radius is limited to the chat system itself and can be undone by deleting messages.

From the tool's definition Tool name 'sendMessage' combined with description 'Send a message to the live chat run' indicates creation/modification of chat data in a live chat system.

Attacks that exploit this kind of access

RECOMMENDED RULE

The rule that runs sendMessage safely

PolicyLayer is an MCP gateway: it sits between your AI agents and Nodebench, and checks every tool call against a rule you set before the call runs. Nothing changes on the server itself. For sendMessage, this is the rule to start with:

sendMessage Rate-limited

sendMessage 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": {
    "sendMessage": {
      "limits": [
        {
          "counter": "sendmessage_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

LIMIT THIS TOOL → Instant setup, no code required.

The button opens the PolicyLayer dashboard: create your workspace, connect Nodebench, apply this rule, and every sendMessage call is checked against it from then on.

FAQ

Questions about sendMessage

What does the sendMessage tool do? +

Send a message to the live chat run. It is categorised as a Write tool in the Nodebench MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on sendMessage? +

Register the Nodebench MCP server in PolicyLayer and add a rule for sendMessage: 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 Nodebench. Nothing to install.

What risk level is sendMessage? +

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

Can I rate-limit sendMessage? +

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

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

sendMessage is provided by the Nodebench MCP server (nodebench-mcp). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.

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