A Model Context Protocol server
Js Sandbox MCP server exists for a simple reason — assistants are far more useful when they can act on Js Sandbox directly instead of describing what you should do. A Model Context Protocol server.
A Model Context Protocol server that provides a secure JavaScript execution environment.
The server ships on npm as @smithery/cli, so your MCP client can launch it on demand — there is no separate build step. Add the server block to your client's configuration, restart it, and the tools register themselves.
Once Js Sandbox is connected, these are the calls the assistant has available:
execute_js — Executes JavaScript code in an isolated environmentParameters — - code (required): JavaScript code to executeTools — The Tools tool exposed by this serverSecurity — The Security tool exposed by this serverDebugging — Since MCP servers communicate over stdio, debugging can be challenging. We recommend using [MCPThis sits in the developer tooling group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. Js Sandbox's toolset — execute_js, Parameters, Tools and 2 more — is a fair guide to whether it matches your workflow. It is maintained by garc33; worth a glance at recent repository activity before you build anything load-bearing on it.
This entry was verified against Js Sandbox's own documentation before publication; SyncDev keeps the directory reviewed rather than auto-generated.
| Tool | What it does |
|---|---|
| execute_js | Executes JavaScript code in an isolated environment |
| Parameters | - code (required): JavaScript code to execute |
| Tools | The Tools tool exposed by this server. |
| Security | The Security tool exposed by this server. |
| Debugging | Since MCP servers communicate over stdio, debugging can be challenging. We recommend using [MCP Inspector](https://github.com/modelcontextprotocol/inspector), which is available as: |
{
"mcpServers": {
"js-sandbox": {
"command": "npx",
"args": ["-y", "@smithery/cli"]
}
}
}Add to claude_desktop_config.json, then restart Claude Desktop.
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