diff --git a/bin/default.nix b/bin/default.nix
index fb171bb..21485d2 100644
--- a/bin/default.nix
+++ b/bin/default.nix
@@ -23,7 +23,7 @@ in lib.mapAttrs (k: f: f k) {
   screenshot_public =
     compileShell ./screenshot_public.sh (with pkgs; [ scrot xclip rsync ]);
   # impure
-  y-cal-widget = makeWrap (toString ./cal.py) "${
+  y-cal-widget = makeWrap ./cal.py "${
       python3.withPackages (p: [ (p.toPythonModule gcalcli) p.i3ipc ])
     }/bin/python";
 }
diff --git a/config.nix b/config.nix
index fe821b3..a3b6c14 100644
--- a/config.nix
+++ b/config.nix
@@ -1,5 +1,4 @@
-let sources = import ./nix/sources.nix;
-in {
+{
   allowUnfree = true;
   # chromium.vaapiSupport = true;
   android_sdk.accept_license = true;
diff --git a/default.nix b/default.nix
deleted file mode 100644
index e9fdf76..0000000
--- a/default.nix
+++ /dev/null
@@ -1,2 +0,0 @@
-let sources = import ./nix/sources.nix;
-in import sources.nixpkgs (import ./config.nix)
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..a45ddd0
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,219 @@
+{
+  "nodes": {
+    "blobs": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1604995301,
+        "narHash": "sha256-wcLzgLec6SGJA8fx1OEN1yV/Py5b+U5iyYpksUY/yLw=",
+        "owner": "simple-nixos-mailserver",
+        "repo": "blobs",
+        "rev": "2cccdf1ca48316f2cfd1c9a0017e8de5a7156265",
+        "type": "gitlab"
+      },
+      "original": {
+        "owner": "simple-nixos-mailserver",
+        "repo": "blobs",
+        "type": "gitlab"
+      }
+    },
+    "cachix": {
+      "locked": {
+        "lastModified": 1651571855,
+        "narHash": "sha256-KZie6c2J2DUPLjG2PkYSwGLvD6RygA3TxZSPQpctbNI=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "fd43ce017d4c95f47166d28664a004f57458a0b1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-21.11",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "emacs-overlay": {
+      "locked": {
+        "lastModified": 1651640396,
+        "narHash": "sha256-QzqsqK9s/PYMgcUrQUqeKNv/9X5nvnQfX/h2v1fH65Q=",
+        "owner": "nix-community",
+        "repo": "emacs-overlay",
+        "rev": "43b4c2b4eaa3893266661e31bfc87e9915bebeef",
+        "type": "github"
+      },
+      "original": {
+        "id": "emacs-overlay",
+        "type": "indirect"
+      }
+    },
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1650374568,
+        "narHash": "sha256-Z+s0J8/r907g149rllvwhb4pKi8Wam5ij0st8PwAh+E=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "b4a34015c698c7793d592d66adbab377907a2be8",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "home-manager": {
+      "inputs": {
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1651652192,
+        "narHash": "sha256-3FUsIJ81p57rOxODRVZ+anhnVav96VWbgNA1H3Np+TY=",
+        "owner": "nix-community",
+        "repo": "home-manager",
+        "rev": "267462dfb36d447421c789a3adf9d460cd09c147",
+        "type": "github"
+      },
+      "original": {
+        "id": "home-manager",
+        "type": "indirect"
+      }
+    },
+    "nixos-hardware": {
+      "locked": {
+        "lastModified": 1650522846,
+        "narHash": "sha256-SxWHXRI3qJwswyXAtzsi6PKVY3KLNNnb072KaJthII8=",
+        "owner": "NixOS",
+        "repo": "nixos-hardware",
+        "rev": "6b4ebea9093c997c5f275c820e679108de4871ab",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixos-hardware",
+        "type": "indirect"
+      }
+    },
+    "nixos-mailserver": {
+      "inputs": {
+        "blobs": "blobs",
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "utils": "utils"
+      },
+      "locked": {
+        "lastModified": 1652050932,
+        "narHash": "sha256-1lOa33Z2sC6CmNdqkCtplVHlMUWVZl4FLT6MYOM+WJQ=",
+        "owner": "simple-nixos-mailserver",
+        "repo": "nixos-mailserver",
+        "rev": "4396125ebbbaecbaba0f8e0afb25e492b3be5795",
+        "type": "gitlab"
+      },
+      "original": {
+        "owner": "simple-nixos-mailserver",
+        "repo": "nixos-mailserver",
+        "type": "gitlab"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1651558728,
+        "narHash": "sha256-8HzyRnWlgZluUrVFNOfZAOlA1fghpOSezXvxhalGMUo=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "cbe587c735b734405f56803e267820ee1559e6c1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-mozilla": {
+      "locked": {
+        "lastModified": 1650459918,
+        "narHash": "sha256-sroCK+QJTmoXtcRkwZyKOP9iAYOPID2Bwdxn4GkG16w=",
+        "owner": "mozilla",
+        "repo": "nixpkgs-mozilla",
+        "rev": "e1f7540fc0a8b989fb8cf701dc4fd7fc76bcf168",
+        "type": "github"
+      },
+      "original": {
+        "owner": "mozilla",
+        "repo": "nixpkgs-mozilla",
+        "type": "github"
+      }
+    },
+    "nixpkgs-stable": {
+      "locked": {
+        "lastModified": 1645296114,
+        "narHash": "sha256-y53N7TyIkXsjMpOG7RhvqJFGDacLs9HlyHeSTBioqYU=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "530a53dcbc9437363471167a5e4762c5fcfa34a1",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "ref": "nixos-21.05",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-wayland": {
+      "inputs": {
+        "cachix": "cachix",
+        "flake-compat": "flake-compat",
+        "nixpkgs": [
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1651650203,
+        "narHash": "sha256-C0wXBIcfnSMDEbCanHZJJ8VGXm0PBiFeSs4yEYwZQ1w=",
+        "owner": "nix-community",
+        "repo": "nixpkgs-wayland",
+        "rev": "908bda3a42d3236d5ee22e2942882fa1cedf6a65",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nixpkgs-wayland",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "emacs-overlay": "emacs-overlay",
+        "home-manager": "home-manager",
+        "nixos-hardware": "nixos-hardware",
+        "nixos-mailserver": "nixos-mailserver",
+        "nixpkgs": "nixpkgs",
+        "nixpkgs-mozilla": "nixpkgs-mozilla",
+        "nixpkgs-stable": "nixpkgs-stable",
+        "nixpkgs-wayland": "nixpkgs-wayland"
+      }
+    },
+    "utils": {
+      "locked": {
+        "lastModified": 1605370193,
+        "narHash": "sha256-YyMTf3URDL/otKdKgtoMChu4vfVL3vCMkRqpGifhUn0=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "5021eac20303a61fafe17224c087f5519baed54d",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
new file mode 100644
index 0000000..51c0ee8
--- /dev/null
+++ b/flake.nix
@@ -0,0 +1,45 @@
+{
+  description = "Yoricks dotfiles";
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+    home-manager.inputs.nixpkgs.follows = "nixpkgs";
+    nixpkgs-mozilla.url = "github:mozilla/nixpkgs-mozilla";
+    emacs-overlay.inputs.nixpkgs.follows = "nixpkgs";
+    nixpkgs-wayland.url = "github:nix-community/nixpkgs-wayland";
+    nixpkgs-wayland.inputs.nixpkgs.follows = "nixpkgs";
+    nixpkgs-stable.url = "github:nixos/nixpkgs/nixos-21.05";
+    nixos-mailserver.url = "gitlab:simple-nixos-mailserver/nixos-mailserver";
+    nixos-mailserver.inputs.nixpkgs.follows = "nixpkgs";
+  };
+  outputs = inputs@{ nixpkgs, home-manager, nixpkgs-mozilla, emacs-overlay, nixpkgs-wayland, nixpkgs-stable, nixos-hardware, self, ... }: {
+    overlays.default = [
+      nixpkgs-wayland.overlay
+      nixpkgs-mozilla.overlay
+      emacs-overlay.overlay
+      (import ./fixups.nix)
+      (import ./pkgs)
+      (import ./pkgs/mdr.nix)
+      (import ./nixos/overlay.nix)
+      (final: prev: {
+        stable = nixpkgs-stable.legacyPackages.x86_64-linux;
+        flake-inputs = inputs;
+      })
+    ];
+    legacyPackages.x86_64-linux = import nixpkgs {
+      config = import ./config.nix;
+      system = "x86_64-linux";
+      overlays = self.overlays.default;
+    };
+    nixosConfigurations = self.legacyPackages.x86_64-linux.yorick.machine;
+    homeConfigurations.yorick = home-manager.lib.homeManagerConfiguration {
+      pkgs = self.legacyPackages.x86_64-linux;
+      configuration = import ./home-manager/home.nix;
+      system = "x86_64-linux";
+      username = "yorick";
+      stateVersion = "20.09";
+      homeDirectory = "/home/yorick";
+    };
+    packages.x86_64-linux.yorick-home = self.homeConfigurations.yorick.activationPackage;
+
+  };
+}
diff --git a/home-manager/desktop.nix b/home-manager/desktop.nix
index 208a060..6e8df18 100644
--- a/home-manager/desktop.nix
+++ b/home-manager/desktop.nix
@@ -1,6 +1,6 @@
 { pkgs, options, ... }:
 let
-  bin = pkgs.callPackage /home/yorick/dotfiles/bin { };
+  bin = pkgs.callPackage ../bin { };
   fixed_slack = pkgs.slack.override {
     xdg-utils = pkgs.xdg-utils.overrideAttrs (o: {
       buildInputs = o.buildInputs ++ [ pkgs.makeWrapper ];
@@ -153,7 +153,7 @@ in {
 
   programs.firefox = {
     enable = true;
-    package = pkgs.wrapFirefox pkgs.latest.firefox-bin.unwrapped {
+    package = pkgs.wrapFirefox pkgs.firefox-bin.unwrapped {
       forceWayland = true;
       applicationName = "firefox";
     };
diff --git a/home-manager/home-manager.nix b/home-manager/home-manager.nix
deleted file mode 100644
index 1cd6f9b..0000000
--- a/home-manager/home-manager.nix
+++ /dev/null
@@ -1 +0,0 @@
-let pkgs = import ../.; in pkgs.yorick.home
diff --git a/home-manager/home.nix b/home-manager/home.nix
index 256a68a..a4b7d58 100644
--- a/home-manager/home.nix
+++ b/home-manager/home.nix
@@ -7,15 +7,6 @@ let
     } "${pkgs.thefuck}/bin/thefuck -a > $out";
 in {
   imports = [ ./desktop.nix ./emacs.nix ./lumi.nix ];
-  nixpkgs = {
-    config.allowUnfree = true;
-    inherit (import /home/yorick/dotfiles/config.nix) overlays;
-  };
-  home = {
-    stateVersion = "20.09";
-    username = "yorick";
-    homeDirectory = "/home/yorick";
-  };
   programs = {
     starship = {
       enable = true;
@@ -27,10 +18,7 @@ in {
       settings.aliases.co = "pr checkout";
     };
     direnv.enable = true;
-    home-manager = {
-      enable = true;
-      path = toString /home/yorick/dotfiles;
-    };
+    home-manager.enable = true;
     git = {
       #lfs.enable = true;
       enable = true;
@@ -293,11 +281,10 @@ in {
     #keyserver-options auto-key-retrieve
   '';
   home.file.".mutt" = {
-    source = /home/yorick/dotfiles/mutt/.mutt;
+    source = ../mutt/.mutt;
     recursive = true;
   };
   home.sessionVariables = {
-    HOME_MANAGER_CONFIG =
-      toString ./home.nix; # unused, but checked for existence
+    FLAKE_CONFIG_URI = "/home/yorick/dotfiles#homeConfigurations.yorick";
   };
 }
diff --git a/nix/sources.json b/nix/sources.json
deleted file mode 100644
index 6afd256..0000000
--- a/nix/sources.json
+++ /dev/null
@@ -1,106 +0,0 @@
-{
-    "emacs-overlay": {
-        "branch": "master",
-        "description": "Bleeding edge emacs overlay [maintainer=@adisbladis] ",
-        "homepage": "",
-        "owner": "nix-community",
-        "repo": "emacs-overlay",
-        "rev": "43b4c2b4eaa3893266661e31bfc87e9915bebeef",
-        "sha256": "157bqxbvyxpqbwgp9gk7gvszznr8kr542ay5h46gdz3cmylaqfj3",
-        "type": "tarball",
-        "url": "https://github.com/nix-community/emacs-overlay/archive/43b4c2b4eaa3893266661e31bfc87e9915bebeef.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "home-manager": {
-        "branch": "master",
-        "description": "Manage a user environment using Nix  [maintainer=@rycee] ",
-        "homepage": "https://nix-community.github.io/home-manager/",
-        "owner": "nix-community",
-        "repo": "home-manager",
-        "rev": "267462dfb36d447421c789a3adf9d460cd09c147",
-        "sha256": "0dprd5riydfhh2dmbsgxmdanfy3agrb4b0qk7gmrx9rmkwh2qmfw",
-        "type": "tarball",
-        "url": "https://github.com/nix-community/home-manager/archive/267462dfb36d447421c789a3adf9d460cd09c147.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": "945aa20cd077a8eccb1c42e29f225370b9a8d78b",
-        "sha256": "0qx94wvmaplagiwmrh558iwwr7nhvini40qmlx21myc66z51if32",
-        "type": "tarball",
-        "url": "https://github.com/nmattia/niv/archive/945aa20cd077a8eccb1c42e29f225370b9a8d78b.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "nixos-hardware": {
-        "branch": "master",
-        "description": "A collection of NixOS modules covering hardware quirks.",
-        "homepage": "",
-        "owner": "nixos",
-        "repo": "nixos-hardware",
-        "rev": "6b4ebea9093c997c5f275c820e679108de4871ab",
-        "sha256": "13r0c6dni2mxsgdxjd4bf9irbwp848xvgh15qcn9ra1p29fqf5ab",
-        "type": "tarball",
-        "url": "https://github.com/nixos/nixos-hardware/archive/6b4ebea9093c997c5f275c820e679108de4871ab.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "nixos-mailserver": {
-        "rev": "5675b122a947b40e551438df6a623efad19fd2e7",
-        "sha256": "1fwhb7a5v9c98nzhf3dyqf3a5ianqh7k50zizj8v5nmj3blxw4pi",
-        "type": "tarball",
-        "url": "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/5675b122a947b40e551438df6a623efad19fd2e7/nixos-mailserver-5675b122a947b40e551438df6a623efad19fd2e7.tar.gz",
-        "url_template": "https://gitlab.com/simple-nixos-mailserver/nixos-mailserver/-/archive/<version>/nixos-mailserver-<version>.tar.gz",
-        "version": "5675b122a947b40e551438df6a623efad19fd2e7"
-    },
-    "nixos-stable": {
-        "branch": "nixos-21.05",
-        "description": "Nix Packages collection",
-        "homepage": "",
-        "owner": "nixos",
-        "repo": "nixpkgs",
-        "rev": "530a53dcbc9437363471167a5e4762c5fcfa34a1",
-        "sha256": "11d9m0c4r4kpr3jx3cqblw6ld4d8dwcfv1lk68ipp4c87knwv7fb",
-        "type": "tarball",
-        "url": "https://github.com/nixos/nixpkgs/archive/530a53dcbc9437363471167a5e4762c5fcfa34a1.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "nixpkgs": {
-        "branch": "nixos-unstable",
-        "description": "A read-only mirror of NixOS/nixpkgs tracking the released channels. Send issues and PRs to",
-        "homepage": "https://github.com/NixOS/nixpkgs",
-        "owner": "nixos",
-        "repo": "nixpkgs",
-        "rev": "cbe587c735b734405f56803e267820ee1559e6c1",
-        "sha256": "0jii8slqbwbvrngf9911z3al1s80v7kk8idma9p9k0d5fm3g4z7h",
-        "type": "tarball",
-        "url": "https://github.com/nixos/nixpkgs/archive/cbe587c735b734405f56803e267820ee1559e6c1.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "nixpkgs-mozilla": {
-        "branch": "master",
-        "description": "mozilla related nixpkgs (extends nixos/nixpkgs repo)",
-        "homepage": "",
-        "owner": "mozilla",
-        "repo": "nixpkgs-mozilla",
-        "rev": "e1f7540fc0a8b989fb8cf701dc4fd7fc76bcf168",
-        "sha256": "1b6p0rly0rywq60ks84ghc0n5zrqiafc2r64nlbnlkh9whmh5fmj",
-        "type": "tarball",
-        "url": "https://github.com/mozilla/nixpkgs-mozilla/archive/e1f7540fc0a8b989fb8cf701dc4fd7fc76bcf168.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    },
-    "nixpkgs-wayland": {
-        "branch": "master",
-        "description": "Automated, pre-built packages for Wayland (sway/wlroots) tools for NixOS.",
-        "homepage": "",
-        "owner": "nix-community",
-        "repo": "nixpkgs-wayland",
-        "rev": "908bda3a42d3236d5ee22e2942882fa1cedf6a65",
-        "sha256": "0p2336612cnf99g221hgdmg4di9795v9r6mh241j778zhw21fk0b",
-        "type": "tarball",
-        "url": "https://github.com/nix-community/nixpkgs-wayland/archive/908bda3a42d3236d5ee22e2942882fa1cedf6a65.tar.gz",
-        "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
-    }
-}
diff --git a/nix/sources.nix b/nix/sources.nix
deleted file mode 100644
index b54826a..0000000
--- a/nix/sources.nix
+++ /dev/null
@@ -1,205 +0,0 @@
-# This file has been generated by Niv.
-
-let
-
-  #
-  # The fetchers. fetch_<type> fetches specs of type <type>.
-  #
-
-  fetch_file = pkgs: name: spec:
-    let name' = sanitizeName name + "-src";
-    in if spec.builtin or true then
-      builtins_fetchurl {
-        inherit (spec) url sha256;
-        name = name';
-      }
-    else
-      pkgs.fetchurl {
-        inherit (spec) url sha256;
-        name = name';
-      };
-
-  fetch_tarball = pkgs: name: spec:
-    let name' = sanitizeName name + "-src";
-    in if spec.builtin or true then
-      builtins_fetchTarball {
-        name = name';
-        inherit (spec) url sha256;
-      }
-    else
-      pkgs.fetchzip {
-        name = name';
-        inherit (spec) url sha256;
-      };
-
-  fetch_git = name: spec:
-    let
-      ref = if spec ? ref then
-        spec.ref
-      else if spec ? branch then
-        "refs/heads/${spec.branch}"
-      else if spec ? tag then
-        "refs/tags/${spec.tag}"
-      else
-        abort
-        "In git source '${name}': Please specify `ref`, `tag` or `branch`!";
-    in builtins.fetchGit {
-      url = spec.repo;
-      inherit (spec) rev;
-      inherit ref;
-    };
-
-  fetch_local = spec: spec.path;
-
-  fetch_builtin-tarball = name:
-    throw ''
-      [${name}] The niv type "builtin-tarball" is deprecated. You should instead use `builtin = true`.
-              $ niv modify ${name} -a type=tarball -a builtin=true'';
-
-  fetch_builtin-url = name:
-    throw ''
-      [${name}] The niv type "builtin-url" will soon be deprecated. You should instead use `builtin = true`.
-              $ niv modify ${name} -a type=file -a builtin=true'';
-
-  #
-  # Various helpers
-  #
-
-  # https://github.com/NixOS/nixpkgs/pull/83241/files#diff-c6f540a4f3bfa4b0e8b6bafd4cd54e8bR695
-  sanitizeName = name:
-    (concatMapStrings (s: if builtins.isList s then "-" else s)
-      (builtins.split "[^[:alnum:]+._?=-]+"
-        ((x: builtins.elemAt (builtins.match "\\.*(.*)" x) 0) name)));
-
-  # The set of packages used when specs are fetched using non-builtins.
-  mkPkgs = sources: system:
-    let
-      sourcesNixpkgs = import
-        (builtins_fetchTarball { inherit (sources.nixpkgs) url sha256; }) {
-          inherit system;
-        };
-      hasNixpkgsPath = builtins.any (x: x.prefix == "nixpkgs") builtins.nixPath;
-      hasThisAsNixpkgsPath = <nixpkgs> == ./.;
-    in if builtins.hasAttr "nixpkgs" sources then
-      sourcesNixpkgs
-    else if hasNixpkgsPath && !hasThisAsNixpkgsPath then
-      import <nixpkgs> { }
-    else
-      abort ''
-        Please specify either <nixpkgs> (through -I or NIX_PATH=nixpkgs=...) or
-        add a package called "nixpkgs" to your sources.json.
-      '';
-
-  # The actual fetching function.
-  fetch = pkgs: name: spec:
-
-    if !builtins.hasAttr "type" spec then
-      abort "ERROR: niv spec ${name} does not have a 'type' attribute"
-    else if spec.type == "file" then
-      fetch_file pkgs name spec
-    else if spec.type == "tarball" then
-      fetch_tarball pkgs name spec
-    else if spec.type == "git" then
-      fetch_git name spec
-    else if spec.type == "local" then
-      fetch_local spec
-    else if spec.type == "builtin-tarball" then
-      fetch_builtin-tarball name
-    else if spec.type == "builtin-url" then
-      fetch_builtin-url name
-    else
-      abort
-      "ERROR: niv spec ${name} has unknown type ${builtins.toJSON spec.type}";
-
-  # If the environment variable NIV_OVERRIDE_${name} is set, then use
-  # the path directly as opposed to the fetched source.
-  replace = name: drv:
-    let
-      saneName = stringAsChars
-        (c: if isNull (builtins.match "[a-zA-Z0-9]" c) then "_" else c) name;
-      ersatz = builtins.getEnv "NIV_OVERRIDE_${saneName}";
-    in if ersatz == "" then
-      drv
-    else
-    # this turns the string into an actual Nix path (for both absolute and
-    # relative paths)
-    if builtins.substring 0 1 ersatz == "/" then
-      /. + ersatz
-    else
-      /. + builtins.getEnv "PWD" + "/${ersatz}";
-
-  # Ports of functions for older nix versions
-
-  # a Nix version of mapAttrs if the built-in doesn't exist
-  mapAttrs = builtins.mapAttrs or (f: set:
-    with builtins;
-    listToAttrs (map (attr: {
-      name = attr;
-      value = f attr set.${attr};
-    }) (attrNames set)));
-
-  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/lists.nix#L295
-  range = first: last:
-    if first > last then
-      [ ]
-    else
-      builtins.genList (n: first + n) (last - first + 1);
-
-  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L257
-  stringToCharacters = s:
-    map (p: builtins.substring p 1 s) (range 0 (builtins.stringLength s - 1));
-
-  # https://github.com/NixOS/nixpkgs/blob/0258808f5744ca980b9a1f24fe0b1e6f0fecee9c/lib/strings.nix#L269
-  stringAsChars = f: s: concatStrings (map f (stringToCharacters s));
-  concatMapStrings = f: list: concatStrings (map f list);
-  concatStrings = builtins.concatStringsSep "";
-
-  # https://github.com/NixOS/nixpkgs/blob/8a9f58a375c401b96da862d969f66429def1d118/lib/attrsets.nix#L331
-  optionalAttrs = cond: as: if cond then as else { };
-
-  # fetchTarball version that is compatible between all the versions of Nix
-  builtins_fetchTarball = { url, name ? null, sha256 }@attrs:
-    let inherit (builtins) lessThan nixVersion fetchTarball;
-    in if lessThan nixVersion "1.12" then
-      fetchTarball
-      ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
-    else
-      fetchTarball attrs;
-
-  # fetchurl version that is compatible between all the versions of Nix
-  builtins_fetchurl = { url, name ? null, sha256 }@attrs:
-    let inherit (builtins) lessThan nixVersion fetchurl;
-    in if lessThan nixVersion "1.12" then
-      fetchurl
-      ({ inherit url; } // (optionalAttrs (!isNull name) { inherit name; }))
-    else
-      fetchurl attrs;
-
-  # Create the final "sources" from the config
-  mkSources = config:
-    mapAttrs (name: spec:
-      if builtins.hasAttr "outPath" spec then
-        abort
-        "The values in sources.json should not have an 'outPath' attribute"
-      else
-        spec // { outPath = replace name (fetch config.pkgs name spec); })
-    config.sources;
-
-  # The "config" used by the fetchers
-  mkConfig = { sourcesFile ?
-      if builtins.pathExists ./sources.json then ./sources.json else null
-    , sources ? if isNull sourcesFile then
-      { }
-    else
-      builtins.fromJSON (builtins.readFile sourcesFile)
-    , system ? builtins.currentSystem, pkgs ? mkPkgs sources system }: rec {
-      # The sources, i.e. the attribute set of spec name to spec
-      inherit sources;
-
-      # The "pkgs" (evaluated nixpkgs) to use for e.g. non-builtin fetchers
-      inherit pkgs;
-    };
-
-in mkSources (mkConfig { }) // {
-  __functor = _: settings: mkSources (mkConfig settings);
-}
diff --git a/nixos/logical/zazu.nix b/nixos/logical/zazu.nix
index ca99c48..42df95a 100644
--- a/nixos/logical/zazu.nix
+++ b/nixos/logical/zazu.nix
@@ -1,13 +1,12 @@
 # Edit this configuration file to define what should be installed on your system.  Help is available in the configuration.nix(5) man page and in the NixOS manual (accessible by running ‘nixos-help’).
-let sources = import ../../nix/sources.nix;
-in { config, lib, pkgs, ... }:
+{ config, lib, pkgs, inputs, ... }:
 
 {
   imports = [ # Include the results of the hardware scan.
     ../physical/apu2c4.nix
     #<yori-nix/roles/homeserver.nix>
     ../roles
-    "${sources.nixos-hardware}/pcengines/apu"
+    inputs.nixos-hardware.nixosModules.pcengines-apu
     <nixpkgs/nixos/modules/profiles/minimal.nix>
   ];
 
diff --git a/nixos/modules/muflax-blog.nix b/nixos/modules/muflax-blog.nix
index eeed725..53d07e1 100644
--- a/nixos/modules/muflax-blog.nix
+++ b/nixos/modules/muflax-blog.nix
@@ -1,4 +1,4 @@
-{ cur_pkgs, config, lib, ... }:
+{ pkgs, config, lib, ... }:
 
 let
   cfg = config.services.muflax-blog;
@@ -11,7 +11,7 @@ let
     url =
       "https://github.com/NixOS/nixpkgs-channels/archive/78e9665b48ff45d3e29f45b3ebeb6fc6c6e19922.tar.gz";
     sha256 = "09f50jaijvry9lrnx891qmcf92yb8qs64n1cvy0db2yjrmxsxyw8";
-  }) { system = builtins.currentSystem; };
+  }) { system = pkgs.stdenv.system; };
   blog = lib.overrideDerivation
     (nixpkgs.callPackage "${muflax-source}/maintenance" { }) (default: {
       buildPhase = default.buildPhase + "\n" + ''
diff --git a/nixos/overlay.nix b/nixos/overlay.nix
index cac1450..cc18ad6 100644
--- a/nixos/overlay.nix
+++ b/nixos/overlay.nix
@@ -5,6 +5,7 @@ in pkgs: super: {
       let
         c = import (pkgs.path + "/nixos/lib/eval-config.nix") {
           inherit (pkgs.stdenv.hostPlatform) system;
+          specialArgs.inputs = pkgs.flake-inputs;
           modules =
             [ ({ lib, ... }: {
               config.nixpkgs.pkgs = lib.mkDefault pkgs;
diff --git a/nixos/physical/3950x.nix b/nixos/physical/3950x.nix
index 3fa937c..dddec1c 100644
--- a/nixos/physical/3950x.nix
+++ b/nixos/physical/3950x.nix
@@ -1,8 +1,8 @@
-{ config, pkgs, lib, ... }:
-let sources = import ../../nix/sources.nix;
-in {
+{ config, pkgs, lib, inputs, ... }:
+{
   imports = [
     ./.
+    inputs.nixos-hardware.nixosModules.common-cpu-amd;
     ./3950x-hardware-config.nix
     "${sources.nixos-hardware}/common/cpu/amd"
   ];
diff --git a/nixos/physical/fractal.nix b/nixos/physical/fractal.nix
index 795af36..25114d7 100644
--- a/nixos/physical/fractal.nix
+++ b/nixos/physical/fractal.nix
@@ -1,7 +1,6 @@
-{ config, lib, pkgs, ... }:
-let sources = import ../../nix/sources.nix;
-in {
-  imports = [ ./. "${sources.nixos-hardware}/common/cpu/intel" ];
+{ config, lib, pkgs, inputs, ... }:
+{
+  imports = [ ./. inputs.nixos-hardware.nixosModules.common-cpu-intel ];
 
   boot.initrd.availableKernelModules =
     [ "xhci_pci" "ehci_pci" "ahci" "usb_storage" "sd_mod" ];
diff --git a/nixos/physical/nuc.nix b/nixos/physical/nuc.nix
index 411ba84..7140247 100644
--- a/nixos/physical/nuc.nix
+++ b/nixos/physical/nuc.nix
@@ -1,11 +1,9 @@
-{ config, lib, pkgs, modulesPath, ... }:
-let sources = import ../../nix/sources.nix;
-in {
-
+{ config, lib, pkgs, inputs, modulesPath, ... }:
+{
   imports = [
     (modulesPath + "/installer/scan/not-detected.nix")
     ./.
-    "${sources.nixos-hardware}/common/cpu/intel"
+    inputs.nixos-hardware.nixosModules.common-cpu-intel
   ];
   boot.loader.systemd-boot.enable = true;
   boot.loader.efi.canTouchEfiVariables = true;
diff --git a/nixos/physical/x11.nix b/nixos/physical/x11.nix
index 3fb2eb7..dfd0fa4 100644
--- a/nixos/physical/x11.nix
+++ b/nixos/physical/x11.nix
@@ -1,9 +1,8 @@
-{ config, pkgs, lib, ... }:
-let sources = import ../../nix/sources.nix;
-in {
+{ config, pkgs, lib, inputs, ... }:
+{
   imports = [
     ./.
-    "${sources.nixos-hardware}/lenovo/thinkpad/x1"
+    inputs.nixos-hardware.nixosModules.lenovo-thinkpad-x1
     ./x11-hardware-config.nix
   ];
 
diff --git a/nixos/physical/xps9360.nix b/nixos/physical/xps9360.nix
index faa7906..87dbf2d 100644
--- a/nixos/physical/xps9360.nix
+++ b/nixos/physical/xps9360.nix
@@ -1,8 +1,7 @@
-{ config, lib, pkgs, ... }:
-let sources = import ../../nix/sources.nix;
-in {
+{ config, lib, pkgs, inputs, ... }:
+{
   imports = [
-    "${sources.nixos-hardware}/dell/xps/13-9360"
+    inputs.nixos-hardware.nixosModules.dell-xps-13-9360;
     ./xps9360-hardware-config.nix
   ];
 
diff --git a/nixos/services/email.nix b/nixos/services/email.nix
index 9a524ab..a153f1a 100644
--- a/nixos/services/email.nix
+++ b/nixos/services/email.nix
@@ -1,7 +1,6 @@
-{ config, pkgs, lib, ... }:
-let sources = import ../../nix/sources.nix;
-in {
-  imports = [ ("${sources.nixos-mailserver}") ];
+{ config, pkgs, lib, inputs, ... }:
+{
+  imports = [ inputs.nixos-mailserver.nixosModule ];
 
   mailserver = rec {
     enable = true;
diff --git a/nixos/services/muflax-church.nix b/nixos/services/muflax-church.nix
index e383050..5eb3395 100644
--- a/nixos/services/muflax-church.nix
+++ b/nixos/services/muflax-church.nix
@@ -10,7 +10,7 @@ let
     url =
       "https://github.com/NixOS/nixpkgs-channels/archive/78e9665b48ff45d3e29f45b3ebeb6fc6c6e19922.tar.gz";
     sha256 = "09f50jaijvry9lrnx891qmcf92yb8qs64n1cvy0db2yjrmxsxyw8";
-  }) { system = builtins.currentSystem; };
+  }) { system = pkgs.stdenv.system; };
   muflax-church =
     (nixpkgs.callPackage "${muflax-source}/maintenance" { }).overrideDerivation
     (default: {
diff --git a/overlay.nix b/overlay.nix
deleted file mode 100644
index 1cd9a22..0000000
--- a/overlay.nix
+++ /dev/null
@@ -1,10 +0,0 @@
-let sources = import ./nix/sources.nix;
-in pkgs: super: {
-  yorick = super.yorick // rec {
-    home = { check ? true, newsReadIdsFile ? null }:
-      import "${sources.home-manager}/home-manager/home-manager.nix" {
-        confPath = ./home-manager/home.nix;
-        inherit pkgs check newsReadIdsFile;
-      };
-  };
-}
diff --git a/overlays.nix b/overlays.nix
deleted file mode 100644
index fe6ae6e..0000000
--- a/overlays.nix
+++ /dev/null
@@ -1,11 +0,0 @@
-let sources = import ./nix/sources.nix;
-in [
-  (import ./fixups.nix)
-  (import "${sources.nixpkgs-wayland}/overlay.nix")
-  (import sources.nixpkgs-mozilla)
-  (import sources.emacs-overlay)
-  (import ./pkgs)
-  (import ./pkgs/mdr.nix)
-  (import ./nixos/overlay.nix)
-  (import ./overlay.nix)
-]
diff --git a/pkgs/default.nix b/pkgs/default.nix
index ea5116a..7dc6c94 100644
--- a/pkgs/default.nix
+++ b/pkgs/default.nix
@@ -3,7 +3,8 @@
   yori-cc = super.callPackage ./yori-cc.nix { };
 
   ftb = super.callPackage ./ftb.nix {};
-  pyroscope = (import (import ../nix/sources.nix).nixos-stable {}).callPackage ./pyroscope {}; # TODO: update this
+  # todo: python 2 -> 3
+  pyroscope = self.stable.callPackage ./pyroscope {};
 
   yscripts = super.callPackage ../bin {};
   factorio = super.factorio.override {