An absolute file path (which should be outside the Nix-store) to a key used for encrypting session cookies. Use srht-keygen service to generate the service key. This must be shared between each node of the same service (e.g. git1.sr.ht and git2.sr.ht), but different services may use different keys. If you configure all of your services with the same config.ini, you may use the same service-key for all of them.
option