Follow these steps to run the MCP Node code sandbox server and tools via Meshagent in the cloud.

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1. Install Meshagent Python package

pip install "meshagent[all]"

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2. Sign up and authenticate

Follow Meshagent CLI Getting Started to create an account and authenticate:

meshagent login

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3. Start an MCP Code Sandbox MCP server in a Meshagent room

meshagent service test \
  --room=test \
  --role=agent \
  --image=meshagent/mcp-node-code-sandbox:latest \
  --env MESHAGENT_PORT=8001 \
  --port="num=8001 path=/webhook liveness=/ type=meshagent.callable" \
  --name=mcp-node-code-sandbox-service
  • This starts a Meshagent Room named test with the MCP server available in the room.
  • Rooms close automatically if inactive.

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4. Join the room with a chatbot agent and tool

meshagent chatbot join \
  --room=test \
  --agent-name=sample \
  --name=sample \
  --toolkit=mcp-node-code-sandbox
  • This launches a chatbot in the Meshagent Room that can use the Node.js code sandbox toolkit.
  • Multiple toolkits can be loaded for the same agent in a room.
  • A room link will be shown in the output, which you can use to interact with the agent and its tools.

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Tools Available

Below are the tools provided by the MCP Node.js code sandbox server, as available through Meshagent:

Tool NameSummary
get_dependency_typesGiven an array of npm package names (and optional versions), fetch whether each package ships its own TypeScript definitions or has a corresponding @types/… package, and return the raw .d.ts text.
run_jsInstall npm dependencies and run JavaScript code inside a running sandbox container.
run_js_ephemeralRun a JavaScript snippet in a temporary disposable container with optional npm dependencies, then automatically clean up.
sandbox_execExecute one or more shell commands inside a running sandbox container.
sandbox_initializeStart a new isolated Docker container running Node.js.
sandbox_stopTerminate and remove a running sandbox container.

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Tool Details

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get_dependency_types

Given an array of npm package names (and optional versions), fetch whether each package ships its own TypeScript definitions or has a corresponding @types/… package, and return the raw .d.ts text.

Useful to inspect APIs and types exposed by dependencies before running Node.js scripts.

ParameterTypeDescription
dependenciesarrayArray of npm package names/versions

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run_js

Install npm dependencies and run JavaScript code inside a running sandbox container.
Manual container stop required to free resources. Code must use ESModules (import/export syntax). Useful for complex workflows with environment reuse.

Use the ./files directory for persistent read/write operations.

ParameterTypeDescription
codestringJavaScript code to run inside the container.
container_idstringDocker container identifier.
dependenciesarray*Optional list of npm dependencies with name and version.
listenOnPortnumber*Optional: Expose container process on this port.

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run_js_ephemeral

Run JS code in a temporary container with optional dependencies, then auto-cleanup.
Use ESModules, best for single-use execution; all file IO should happen in ./files.

Example:

import fs from "fs/promises";
await fs.writeFile("./files/hello.txt", "Hello world!");
console.log("Saved ./files/hello.txt");
ParameterTypeDescription
codestringJavaScript code to run ephemerally.
dependenciesarray*Optional npm dependencies (name/version).
imagestring*Optional Docker image for execution. E.g. node:lts-slim, mcr.microsoft.com/playwright, etc.

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sandbox_exec

Execute one or more shell commands within a running Node.js sandbox container.

ParameterTypeDescription
commandsarrayCommands to execute.
container_idstringTarget container ID.

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sandbox_initialize

Start a new isolated Docker container running Node.js.

ParameterTypeDescription
imagestring*Optional base image.
portnumber*Optional port mapping.

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sandbox_stop

Terminate and remove a running sandbox container.
Call after finishing work in a sandbox.

ParameterTypeDescription
container_idstringID of the container