My take so far is that there isn’t really any great options to protect against prompt injections. Simon Wilson presents an idea here on his blog which could is a bit interesting. NVIDIA has open sourced a framework for this as well, but it’s not without problems. Otherwise I’ve mostly seen prompt injection firewall products but I wouldn’t trust them too much yet.

Looks like you’re right. It’s not mentioned on that page but here he says he’s the one running it.