{
  inputs = {
    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
  };

  outputs = { self, nixpkgs }: {
    
  };
}

for a flake like this, it would be nice to get completions and types for self and nixpkgs
Here is a list of attributes copied from docs: outPath, rev, revCount, lastModifiedDate, lastModified, narHash