Yep you can make them permanent.  Create your config in /etc/wireguard/wg0.conf.  Then run 'systemctl enable wg-quick@wg0'  (assuming you're running systemd).
wg-quick takes care of interface creation, interface and endpoint IP addressing, routing, and peer keys; so you just create that file and then use 'wg-quick up wg0'.  :)
I wrote a few blog posts on setting up wg to act as a bridge into a remote network; you can probably use a lot of the info from there to get you started:   https://www.ericlight.com/wireguard-part-one-installation
E

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Q: Why is this email five sentences or less?
A: http://five.sentenc.es



On Sat, 22 Jul 2017, at 11:54, Sahil Gupta wrote:
> Sorry, my bad.
> I copy paste configuration of Peer A in both Peer A and B in this email.> I will follow the advise of Jason.
> 
> I switched off both Laptops and now wg interface are gone.
> I need to create them again.
> Can we make these interfaces permanent so they will not go upon switching off the laptop?> 
> I will mail again if problem still persists.
> Thanks
> Sahil Gupta