The path to a file containing the secret_key_base secret. Discourse uses secret_key_base to encrypt the cookie store, which contains session data, and to digest user auth tokens. Needs to be a 64 byte long string of hexadecimal characters. You can generate one by running openssl rand -hex 64 >/path/to/secret_key_base_file This should be a string, not a nix path, since nix paths are copied into the world-readable nix store.

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"/run/keys/secret_key_base"