So the keys never leave the phone, and all the signing/encrypting/decryption requests & responses are sent over some internal browser-specific api? (i.e. the Safari on my phone can communicate with the Safari on my laptop, if I’m logged in).
No, nothing Safari-specific, keys must be on the same browser on the same device. This doesn't work across devices
Bummer.
I don’t want my nsec to ever leave my phone.
I know that WhatsApp Web used to force you to connect your computer to the same WiFi as your phone. I guess it’s because they didn’t want the computer to interact directly with their servers, and instead it communicated with the phone over the local network. Maybe you could do something similar.