{
  description = "pygea - Pangea RSS feed generator";

  inputs = {
    nixpkgs.url = "https://flakehub.com/f/NixOS/nixpkgs/0.1";
    treefmt-nix = {
      url = "github:numtide/treefmt-nix";
      inputs.nixpkgs.follows = "nixpkgs";
    };
  };

  outputs =
    {
      self,
      nixpkgs,
      treefmt-nix,
      ...
    }:
    let
      systems = [ "x86_64-linux" ];
      forAllSystems =
        fn:
        nixpkgs.lib.genAttrs systems (
          system:
          fn (
            import nixpkgs {
              inherit system;
              config.allowUnfree = true;
            }
          )
        );

      mkTreefmtConfig = pkgs: (treefmt-nix.lib.evalModule pkgs ./treefmt.nix).config;
    in
    {
      formatter = forAllSystems (pkgs: (mkTreefmtConfig pkgs).build.wrapper);

      packages = forAllSystems (
        pkgs:
        let
          pkg = pkgs.callPackage ./nix/packages/pygea/package.nix { };
        in
        {
          pygea = pkg;
          default = pkg;
        }
      );

      apps = forAllSystems (
        pkgs:
        let
          package = self.packages.${pkgs.stdenv.hostPlatform.system}.default;
        in
        {
          pygea = {
            type = "app";
            program = "${package}/bin/pygea";
            meta.description = "pygea runtime";
          };
          default = {
            type = "app";
            program = "${package}/bin/pygea";
            meta.description = "pygea runtime";
          };
        }
      );

      checks = forAllSystems (
        pkgs:
        let
          inherit (pkgs.stdenv.hostPlatform) system;
          exportedPackage = self.packages.${system}.default;
          treefmtConfig = mkTreefmtConfig pkgs;
          smokePython = pkgs.python313.withPackages (ps: [
            ps.requests
            ps.beautifulsoup4
            ps.feedgen
            ps."python-dateutil"
            ps.pytest
          ]);

          smokeCheck = pkgs.runCommand "pygea-smoke" { nativeBuildInputs = [ smokePython ]; } ''
            export PYTHONPATH="${exportedPackage}/${pkgs.python313.sitePackages}:$PYTHONPATH"
            python - <<'PY'
            from pathlib import Path

            for source_file in Path("${./.}/pygea").glob("*.py"):
                compile(source_file.read_text(encoding="utf-8"), str(source_file), "exec")
            PY
            python -c "import pygea; import pygea.utilities; import pygea.pexception"
            mkdir -p "$out"
            touch "$out/passed"
          '';

          pytestCheck = pkgs.runCommand "pygea-pytest" { nativeBuildInputs = [ smokePython ]; } ''
            export PYTHONPATH="${./.}:$PYTHONPATH"
            cd ${./.}
            pytest
            mkdir -p "$out"
            touch "$out/passed"
          '';

          deadnixCheck = pkgs.runCommand "pygea-deadnix" { nativeBuildInputs = [ pkgs.deadnix ]; } ''
            cd ${./.}
            deadnix --fail .
            mkdir -p "$out"
            touch "$out/passed"
          '';

          statixCheck = pkgs.runCommand "pygea-statix" { nativeBuildInputs = [ pkgs.statix ]; } ''
            cd ${./.}
            statix check
            mkdir -p "$out"
            touch "$out/passed"
          '';
        in
        {
          devshell-default = self.devShells.${system}.default;
          formatter = treefmtConfig.build.wrapper;
          package-default = exportedPackage;
          treefmt = treefmtConfig.build.check ./.;
          smoke = smokeCheck;
          pytest = pytestCheck;
          deadnix = deadnixCheck;
          statix = statixCheck;
        }
      );

      devShells = forAllSystems (
        pkgs:
        let
          treefmtConfig = mkTreefmtConfig pkgs;
        in
        {
          default = pkgs.mkShell {
            packages = [
              pkgs.python313
              pkgs.uv
              self.packages.${pkgs.stdenv.hostPlatform.system}.default
              treefmtConfig.build.wrapper
              pkgs.deadnix
              pkgs.statix
            ];
          };
        }
      );
    };
}