1{den, ...}: {
 2  flake-file.inputs.flake-parts.url = "github:hercules-ci/flake-parts";
 3
 4  # Read flake-parts classes from hosts and their includes
 5  den.policies.flake-parts-to-host = _:
 6    map (host: den.lib.policy.resolve.to "host" {inherit host;}) (
 7      builtins.concatMap builtins.attrValues (builtins.attrValues den.hosts)
 8    );
 9  den.schema.flake-parts.includes = [den.policies.flake-parts-to-host];
10
11  # Enter flake-parts scope from flake-system.
12  den.schema.flake-system.includes = [den.policies.system-to-flake-parts];
13
14  debug = true;
15}