nixos-config/nix/sources.json

{
    "home-manager": {
        "branch": "release-23.05",
        "description": "Manage a user environment using Nix  [maintainer=@rycee] ",
        "homepage": "https://nix-community.github.io/home-manager/",
        "owner": "nix-community",
        "repo": "home-manager",
        "rev": "2d963854ae2499193c0c72fd67435fee34d3e4fd",
        "sha256": "1851n81s5z5gliq9ymcw1k1z46rhgb3q3q8b7qiim2y8phbmdbhy",
        "type": "tarball",
        "url": "https://github.com/nix-community/home-manager/archive/2d963854ae2499193c0c72fd67435fee34d3e4fd.tar.gz",
        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
    },
    "niv": {
        "branch": "master",
        "description": "Easy dependency management for Nix projects",
        "homepage": "https://github.com/nmattia/niv",
        "owner": "nmattia",
        "repo": "niv",
        "rev": "0ebb80e003c26d5388a9b74645fbdcfca3bdd0ef",
        "sha256": "0wpnk1n4vjyqwjjrm6dvkyh7xr7983rszfhfcg31v106qhfnh41c",
        "type": "tarball",
        "url": "https://github.com/nmattia/niv/archive/0ebb80e003c26d5388a9b74645fbdcfca3bdd0ef.tar.gz",
        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
    }
}