Runno MCP

An MCP server that provides sandboxed code execution for multiple programming languages including Python, Ruby, JavaScript (QuickJS), SQLite, C, C++, and PHP. Built on top of WebAssembly and WASI, Runno runs code safely in an isolated environment with a virtual file system and no network access.

Supported Languages

• Python - Python 3.6+
• Ruby - Ruby 3.2.0+
• JavaScript - via QuickJS engine
• SQLite - SQL commands
• C - compiled with Clang
• C++ - compiled with Clang++
• PHP - PHP CGI

Features

• Sandboxed execution using WebAssembly
• Virtual file system (in-memory)
• No network access for security
• STDIN/STDOUT support
• Runs WASI binaries
• No installation required for end users

Security

Runno provides strong isolation through:

• WebAssembly virtualization (code doesn't run directly on CPU/RAM)
• Separation of code and data
• Virtual file system (never accesses real filesystem)
• No network access
• Limited system interface via WASI preview1

For more information, see the MCP introduction article.