Secrets like SECRET_KEY_BASE and BASIC_AUTH_PASSWORD should be passed to the service without adding them to the world-readable Nix store.
Note that either this file needs to be available on the host on which pinchflat is running, or the option selfhosted must be true. Further, SECRET_KEY_BASE has a minimum length requirement of 64 bytes. One way to generate such a secret is to use openssl rand -hex 64.
As an example, the contents of the file might look like this:
SECRET_KEY_BASE=...copy-paste a secret token here...
BASIC_AUTH_USERNAME=...basic auth username...
BASIC_AUTH_PASSWORD=...basic auth password...
Declarations
Type
null or absolute pathDefault
nullExample
"/run/secrets/pinchflat"