So I’m not aiming to create something that can run existing Elixir projects, just something that allows users to program select parts of websites.

That’s a good question. It should be noted that this limitation is one-directional. You can run Sand code in Elixir if you import the macro r (and, in the future, possibly load).

An example use case would be allowing untrusted users to run bots on chat site, without using a lot of server resources. The server provides user messages to the sandbox and sends the sandbox output back to the chat.

The reason why you’d use this over existing (OS-level) sandbox solutions is that it doesn’t require additional moving parts (just one dependency) and because of the speed and low overhead.

That’s by design, you only get a small share of RAM.

I will update the error message to make this more clear.

Done!

On the demo server, I’ve given each program a generous 1 MB of memory. This is configurable, so more computationally heavy stuff could also be run in the sandbox.

Nice.

The highest number I can use in the demo is factorial.(866). It breaks with 867 and above.