nixos-config/nix/sources.json

{
    "home-manager": {
        "branch": "release-22.05",
        "description": "Manage a user environment using Nix  [maintainer=@rycee] ",
        "homepage": "https://nix-community.github.io/home-manager/",
        "owner": "nix-community",
        "repo": "home-manager",
        "rev": "ac2287df5a2d6f0a44bbcbd11701dbbf6ec43675",
        "sha256": "1bn5m4qlzxc5c264hwyy9n8f7m1pzc79fd0xh18n46wn0v8vx4jn",
        "type": "tarball",
        "url": "https://github.com/nix-community/home-manager/archive/ac2287df5a2d6f0a44bbcbd11701dbbf6ec43675.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": "82e5cd1ad3c387863f0545d7591512e76ab0fc41",
        "sha256": "090l219mzc0gi33i3psgph6s2pwsc8qy4lyrqjdj4qzkvmaj65a7",
        "type": "tarball",
        "url": "https://github.com/nmattia/niv/archive/82e5cd1ad3c387863f0545d7591512e76ab0fc41.tar.gz",
        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
    }
}