wasmerio/wasmer ? reverse-engineered prompt

Build me a fast, lightweight sandbox tool for running apps and AI agent tasks safely on my machine and in the browser.

I want a command line app that can pull ready to run packages like Python or Bash, cache them, and run them inside a secure sandbox with simple options for allowing a folder, turning on network access, and passing through command arguments. It should feel easy enough that I can run something like a hello world Python script or a shell command right away.

Also make it usable as an SDK so I can start a sandbox from my own app and run commands, read output, and work with files inside the sandbox. If it makes sense, include examples for JavaScript, Rust, and Python, plus a small web demo I can open in the browser. Look up current docs online if you need to, and keep the setup and first run as simple as possible.