Deno MCP Server

What is Deno MCP Server?

An MCP (Model Context Protocol) server for executing Deno TypeScript/JavaScript code. It allows LLMs such as Claude to run Deno code securely with configurable permissions (net, read, write, env, run, etc.) and support for unstable features.

How to use Deno MCP Server?

Install Node.js 16+, Deno, and Claude Desktop or Cline. Clone the repository, run npm install and npm run build, then add a JSON configuration entry pointing to dist/index.js in your MCP client’s settings file. Restart the client, then ask Claude to execute Deno code with optional permission flags.

Key features of Deno MCP Server

• Execute Deno TypeScript or JavaScript code
• Grant granular permissions (net, read, write, env, run)
• Enable or disable unstable Deno features
• Retrieve installed Deno version information
• 30-second execution timeout for code safety

Use cases of Deno MCP Server

• Run quick Deno scripts directly through a chat interface
• Fetch external APIs by requesting network permissions
• Read and write files on the local filesystem with read/write permissions
• Combine network and filesystem permissions to fetch and save data
• Experiment with Deno’s standard library modules

FAQ from Deno MCP Server

What prerequisites are needed to use Deno MCP Server?

Node.js 16 or higher, a working Deno installation, and a compatible MCP client (Claude Desktop or Cline) are required.

How do I resolve a “Deno is not found” error?

Ensure Deno is installed and available in your system PATH. The server relies on the deno command being accessible.

Why does my code fail with permission errors?

You must explicitly request the needed permissions (e.g., "net" for network, "read"/"write" for file system, "env" for environment variables, "run" for subprocesses) when invoking execute_deno_code.

Is there a time limit for code execution?

Yes. Code execution is automatically terminated after 30 seconds. Long‑running scripts will hit this timeout.

Where is the configuration file located?

For Claude Desktop, the file is at ~/Library/Application Support/Claude/claude_desktop_config.json (macOS) or under %APPDATA%\Claude (Windows). For Cline, it is at ~/.config/Code/User/globalStorage/saoudrizwan.claude-dev/settings/cline_mcp_settings.json.