Earlier quoted context omitted.
Where is the ssh-agent reading your private key from? If from ~/.ssh/, you're just one "npm install" away from the key being exfiltrated by a compromised package. If the private key is on your Yubikey, you're already good. The 1password agent will provide a good hardwareless method of keeping your private keys off the local filesystem, and it'll sync between your devices too.
> you're just one "npm install" away from the key being exfiltrated It's not as easy as that if your private key is protected with a passphrase, which IMO ought to be the default option. I am amused by the rationalization going on here, though... taking extra steps to secure your SSH private key because you might "npm install" something bad. There's nothing wrong with enhancing the security of your private keys throu…
So it is unreasonable to want to develop a JS app on the same machine I use for SSH?
Docker works I guess, but adds a lot of mental (and in the case of Docker for Mac, performance) overhead.