Codebench MCP Server

This MCP server provides JavaScript execution capabilities with a modern runtime. The codebench mcp mcp server wraps that behind the Model Context Protocol, so an assistant can use it through 3 defined tools rather than through you.

What it actually does

• Console API — console.log(), console.error(), console.warn() (built-in)
• HTTP Server — serve() for server creation (via require('http/server'))
• Fetch API — Modern fetch() with Request, Response, Headers, FormData (global)
• Timers — setTimeout(), setInterval(), clearTimeout(), clearInterval() (global)
• Buffer — Buffer, Blob, File APIs for binary data handling (global)
• Crypto — Cryptographic functions - hashing, encryption, HMAC (via require('crypto'))

Its toolset

Everything the assistant can do here goes through one of these:

• Installation — The Installation tool exposed by this server
• Usage — The Usage tool exposed by this server
• executeJS — // Basic JavaScript execution const result = 2 + 3; console.log('Result:', result);

Adding it to your client

ghcr.io/mark3labs/codebench-mcp on a container image is all you need. Most clients run it directly, so configuration is a few lines and a restart.

When to reach for it

This sits in the knowledge and memory group, where several servers overlap in what they claim to do but differ sharply once you actually set them up. Codebench MCP's toolset — Installation, Usage, executeJS — is a fair guide to whether it matches your workflow. It is maintained by mark3labs; worth a glance at recent repository activity before you build anything load-bearing on it.

We check each listing at SyncDev against the project's documentation before it goes live — if something here drifts out of date, it is a bug worth reporting.

Caveats

• It runs with your machine's permissions. That is convenient and also the reason to think about what you point it at before you approve a tool call.
• MCP clients confirm each tool call by default. Leave that on until you have watched what the codebench mcp mcp server does with a few real requests.