{
  nix.settings = {
    trusted-substituters = [
      "https://cache.nixos.org/"
      "https://nix-community.cachix.org"
      "https://mat.cachix.org"
      "https://helix.cachix.org"
    ];
    trusted-public-keys = [
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      "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
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      "helix.cachix.org-1:ejp9KQpR1FBI2onstMQ34yogDm4OgU2ru6lIwPvuCVs="
    ];
  };
}