diff --git a/.github/workflows/update-data.yml b/.github/workflows/update-data.yml
index b956495..a8dc9b7 100644
--- a/.github/workflows/update-data.yml
+++ b/.github/workflows/update-data.yml
@@ -4,6 +4,9 @@ on:
   schedule:
     - cron: '0 15 * * 1'
   workflow_dispatch:
+  pull_request:
+    paths:
+      - dev/**
 
 concurrency:
   group: ${{ github.workflow }}-${{ github.ref }}
diff --git a/dev/flake-module.nix b/dev/flake-module.nix
new file mode 100644
index 0000000..ce61c3e
--- /dev/null
+++ b/dev/flake-module.nix
@@ -0,0 +1,60 @@
+{ inputs, ... }:
+{
+  perSystem =
+    {
+      system,
+      pkgs,
+      self',
+      lib,
+      ...
+    }:
+    let
+      emacsPackages = inputs.emacs-ci.packages.${system};
+    in
+    {
+      _module.args.pkgs = inputs.nixpkgs.legacyPackages.${system}.extend inputs.twist.overlays.default;
+
+      devShells = {
+        default = pkgs.mkShell { buildInputs = [ pkgs.just ]; };
+      };
+
+      packages = {
+        default = pkgs.linkFarm "default" (
+          [
+            {
+              name = "default.nix";
+              path = pkgs.writeText "emacs-builtins-default-nix" ''{${
+                lib.concatMapStrings (name: "${name} = import ./${name}.nix;\n") (builtins.attrNames emacsPackages)
+              }}'';
+            }
+          ]
+          ++ (lib.mapAttrsToList (emacsName: emacsPackage: {
+            name = "${emacsName}.nix";
+            path =
+              pkgs.runCommand "build-${emacsName}-builtins-nix"
+                {
+                  buildInputs = [ emacsPackage ];
+                }
+                ''
+                  EMACS_VERSION="$(emacs --version \
+                    | grep -F "GNU Emacs" \
+                    | grep -oE "[[:digit:]]+(:?\.[[:digit:]]+)+")"
+                  echo >>$out '{'
+                  echo >>$out "  version = \"''${EMACS_VERSION}\";"
+                  echo >>$out '  libraries = ['
+                  sed -e 's/^/"/' -e 's/$/"/' ${
+                    (pkgs.emacsTwist {
+                      inherit emacsPackage;
+                      initFiles = [ ];
+                      lockDir = null;
+                      inventories = [ ];
+                    }).builtinLibraryList
+                  } >>$out
+                  echo >>$out '  ];'
+                  echo >>$out '}'
+                '';
+          }) emacsPackages)
+        );
+      };
+    };
+}
diff --git a/dev/flake.lock b/dev/flake.lock
new file mode 100644
index 0000000..9678386
--- /dev/null
+++ b/dev/flake.lock
@@ -0,0 +1,459 @@
+{
+  "nodes": {
+    "elisp-helpers": {
+      "inputs": {
+        "fromElisp": "fromElisp"
+      },
+      "locked": {
+        "lastModified": 1741687420,
+        "narHash": "sha256-tWPUfH3hCpB6g7a+0AK3lLYnhKgCxry5+pxNKZ2rQoY=",
+        "owner": "emacs-twist",
+        "repo": "elisp-helpers",
+        "rev": "dd91691d642188f857e3fc3fec3e16719810e6d2",
+        "type": "github"
+      },
+      "original": {
+        "owner": "emacs-twist",
+        "repo": "elisp-helpers",
+        "type": "github"
+      }
+    },
+    "emacs-23-4": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-OzqhctHmsk30IfS61czooF+1LShToeT614RtqrMNyJw=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-23.4.tar.bz2"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-23.4.tar.bz2"
+      }
+    },
+    "emacs-24-1": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-UVWKuXneNHq1zJtkGo6eLacUl5MdEbCBL68a8NcYEWk=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-24.1.tar.bz2"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-24.1.tar.bz2"
+      }
+    },
+    "emacs-24-2": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-zdhQvRQs1ty4b8E4Khf10dCv+iGNuVl4FDCtUFqt2bI=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-24.2.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-24.2.tar.xz"
+      }
+    },
+    "emacs-24-3": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-kANCrStnnt/0Mxt5qV94iKwcXGgFqqhJVUwRSAC0ez4=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-24.3.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-24.3.tar.xz"
+      }
+    },
+    "emacs-24-4": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-WDPY5n3pMF7o4noS941GLDQ2zFKa8PvDkWjeMw0Wsm0=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-24.4.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-24.4.tar.xz"
+      }
+    },
+    "emacs-24-5": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-jb801XX+fMvQ5OBYKpjPPsqAcqgaeYKPRfeZIP8R/rc=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-24.5.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-24.5.tar.xz"
+      }
+    },
+    "emacs-25-1": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-Lxgh6MOMYYaenkgwFiFw4SZOxkGk+q/4bDv3B8rAAWM=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-25.1.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-25.1.tar.xz"
+      }
+    },
+    "emacs-25-2": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-L+Tgth/sI7aI+xQOu5iRWxhaivsK6BcmNB7wV1bUzg0=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-25.2.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-25.2.tar.xz"
+      }
+    },
+    "emacs-25-3": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-1czqSKUzuoJc+WBwpojicwpZE6VKnAqNJt2V04k2ifc=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-25.3.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-25.3.tar.xz"
+      }
+    },
+    "emacs-26-1": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-amsPbiVbko/Qvsw2cfJdkhq0UHGjhn5uyLN0MEeMq20=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-26.1.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-26.1.tar.xz"
+      }
+    },
+    "emacs-26-2": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-AvO73gk6Tb+aDARgbgAq6RVz71wBSxh12RrnrD/3TM0=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-26.2.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-26.2.tar.xz"
+      }
+    },
+    "emacs-26-3": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-iYPYrf/6Cd6wozabn2D/bj9M591vLqO84uPyj3ZN/+I=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-26.3.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-26.3.tar.xz"
+      }
+    },
+    "emacs-27-1": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-oADGvqBASpU8Q512c+PPF1pwm1/tg2oo2a30ghJ2xVQ=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-27.1.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-27.1.tar.xz"
+      }
+    },
+    "emacs-27-2": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-BaLVKUHuxGuO3F+/YRQ8DCe8FkR/fkoJIh6p4xbF4m0=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-27.2.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-27.2.tar.xz"
+      }
+    },
+    "emacs-28-1": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-EGuOesE+gq6wzF4qiqdBQhPm+TGzZnJ/sHxkd4Liz4s=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-28.1.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-28.1.tar.xz"
+      }
+    },
+    "emacs-28-2": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-+Tmn3gJ+7536KehS3QUGRWFc0ic7xZI/KDl63n/yEp4=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-28.2.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-28.2.tar.xz"
+      }
+    },
+    "emacs-29-1": {
+      "flake": false,
+      "locked": {
+        "narHash": "sha256-C7920QvXQvrqUNAScIb++H1+3CC54ppPby+/hh6+yo0=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-29.1.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-29.1.tar.xz"
+      }
+    },
+    "emacs-29-2": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1705573161,
+        "narHash": "sha256-P589A1XNkmj4ODOXosk1sNkUGJsHSgQtIfWsNjCd+eI=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-29.2.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-29.2.tar.xz"
+      }
+    },
+    "emacs-29-3": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1711287509,
+        "narHash": "sha256-F/EO5gasb0bW0TIyudp1HAeZfwYjjE7a3ptK2oQbp7Q=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-29.3.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-29.3.tar.xz"
+      }
+    },
+    "emacs-29-4": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1719016405,
+        "narHash": "sha256-p4jFYnpWdq7op8VqMpvEgdXNkqpyxznli5q6K1TEohk=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-29.4.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-29.4.tar.xz"
+      }
+    },
+    "emacs-30-1": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1740327883,
+        "narHash": "sha256-UNbaj+6JNDydBh0R92i3ec54lLATo2+th31MghgPC8M=",
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-30.1.tar.xz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://ftp.gnu.org/gnu/emacs/emacs-30.1.tar.xz"
+      }
+    },
+    "emacs-ci": {
+      "inputs": {
+        "emacs-23-4": "emacs-23-4",
+        "emacs-24-1": "emacs-24-1",
+        "emacs-24-2": "emacs-24-2",
+        "emacs-24-3": "emacs-24-3",
+        "emacs-24-4": "emacs-24-4",
+        "emacs-24-5": "emacs-24-5",
+        "emacs-25-1": "emacs-25-1",
+        "emacs-25-2": "emacs-25-2",
+        "emacs-25-3": "emacs-25-3",
+        "emacs-26-1": "emacs-26-1",
+        "emacs-26-2": "emacs-26-2",
+        "emacs-26-3": "emacs-26-3",
+        "emacs-27-1": "emacs-27-1",
+        "emacs-27-2": "emacs-27-2",
+        "emacs-28-1": "emacs-28-1",
+        "emacs-28-2": "emacs-28-2",
+        "emacs-29-1": "emacs-29-1",
+        "emacs-29-2": "emacs-29-2",
+        "emacs-29-3": "emacs-29-3",
+        "emacs-29-4": "emacs-29-4",
+        "emacs-30-1": "emacs-30-1",
+        "emacs-release-snapshot": "emacs-release-snapshot",
+        "emacs-snapshot": "emacs-snapshot",
+        "flake-compat": "flake-compat",
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      },
+      "locked": {
+        "lastModified": 1747052064,
+        "narHash": "sha256-x1GldgqzmtfznstZCaOYllvwM0osKUnfhAo1NQ9RIko=",
+        "owner": "purcell",
+        "repo": "nix-emacs-ci",
+        "rev": "ee9a94b86e6d99dfe01a52e7cb7df0e8f2e4b3cc",
+        "type": "github"
+      },
+      "original": {
+        "owner": "purcell",
+        "repo": "nix-emacs-ci",
+        "type": "github"
+      }
+    },
+    "emacs-release-snapshot": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1746978413,
+        "narHash": "sha256-jcuN5RzBPakAlPUTUItA2EtfgI1TjGdC2nnaKQaXmE0=",
+        "owner": "emacs-mirror",
+        "repo": "emacs",
+        "rev": "cbea5997c077878b757b0168762f1a114ee1e484",
+        "type": "github"
+      },
+      "original": {
+        "owner": "emacs-mirror",
+        "ref": "emacs-30",
+        "repo": "emacs",
+        "type": "github"
+      }
+    },
+    "emacs-snapshot": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1746980833,
+        "narHash": "sha256-+LKKo1U6kaB2Dd+zYTfiFaABFa1xkws9tkE93GY/Zhg=",
+        "owner": "emacs-mirror",
+        "repo": "emacs",
+        "rev": "882c849034a909a62179c38ee01cc08572fa1a68",
+        "type": "github"
+      },
+      "original": {
+        "owner": "emacs-mirror",
+        "repo": "emacs",
+        "type": "github"
+      }
+    },
+    "flake-compat": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1673956053,
+        "narHash": "sha256-4gtG9iQuiKITOjNQQeQIpoIB6b16fm+504Ch3sNKLd8=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "35bb57c0c8d8b62bbfd284272c928ceb64ddbde9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1687709756,
+        "narHash": "sha256-Y5wKlQSkgEK2weWdOu4J3riRd+kV/VCgHsqLNTTWQ/0=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "dbabf0ca0c0c4bce6ea5eaf65af5cb694d2082c7",
+        "type": "github"
+      },
+      "original": {
+        "id": "flake-utils",
+        "type": "indirect"
+      }
+    },
+    "fromElisp": {
+      "flake": false,
+      "locked": {
+        "lastModified": 1723987997,
+        "narHash": "sha256-OhaVgTG6zjLByzl+uPTvtCld3p2uqgbCXmOl/s3LVRo=",
+        "owner": "talyz",
+        "repo": "fromElisp",
+        "rev": "f071a0e262c02c0895b575c4e322b7fd90713543",
+        "type": "github"
+      },
+      "original": {
+        "owner": "talyz",
+        "repo": "fromElisp",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1746061036,
+        "narHash": "sha256-OxYwCGJf9VJ2KnUO+w/hVJVTjOgscdDg/lPv8Eus07Y=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "3afd19146cac33ed242fc0fc87481c67c758a59e",
+        "type": "github"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "ref": "nixpkgs-unstable",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "emacs-ci": "emacs-ci",
+        "twist": "twist"
+      }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
+    "twist": {
+      "inputs": {
+        "elisp-helpers": "elisp-helpers"
+      },
+      "locked": {
+        "lastModified": 1741687500,
+        "narHash": "sha256-3XFSz42KAz53k9dzY5C2QbL5R4uiPwwqZ86RPiOYcNg=",
+        "owner": "emacs-twist",
+        "repo": "twist.nix",
+        "rev": "cb0299ed2d7936357288b77d1f22ddbd9e35808d",
+        "type": "github"
+      },
+      "original": {
+        "owner": "emacs-twist",
+        "repo": "twist.nix",
+        "type": "github"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/dev/flake.nix b/dev/flake.nix
new file mode 100644
index 0000000..681d94a
--- /dev/null
+++ b/dev/flake.nix
@@ -0,0 +1,11 @@
+# This is a flake to track dependency-only inputs and outputs. See
+# https://flake.parts/options/flake-parts-partitions.html
+{
+  inputs = {
+    twist.url = "github:emacs-twist/twist.nix";
+    emacs-ci.url = "github:purcell/nix-emacs-ci";
+  };
+
+  # This flake is only used for its inputs.
+  outputs = _: { };
+}
diff --git a/flake.lock b/flake.lock
new file mode 100644
index 0000000..206a00b
--- /dev/null
+++ b/flake.lock
@@ -0,0 +1,61 @@
+{
+  "nodes": {
+    "flake-parts": {
+      "inputs": {
+        "nixpkgs-lib": "nixpkgs-lib"
+      },
+      "locked": {
+        "lastModified": 1743550720,
+        "narHash": "sha256-hIshGgKZCgWh6AYJpJmRgFdR3WUbkY04o82X05xqQiY=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "c621e8422220273271f52058f618c94e405bb0f5",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1747426788,
+        "narHash": "sha256-N4cp0asTsJCnRMFZ/k19V9akkxb7J/opG+K+jU57JGc=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "12a55407652e04dcf2309436eb06fef0d3713ef3",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "ref": "nixpkgs-unstable",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs-lib": {
+      "locked": {
+        "lastModified": 1743296961,
+        "narHash": "sha256-b1EdN3cULCqtorQ4QeWgLMrd5ZGOjLSLemfa00heasc=",
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "rev": "e4822aea2a6d1cdd36653c134cacfd64c97ff4fa",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "nixpkgs.lib",
+        "type": "github"
+      }
+    },
+    "root": {
+      "inputs": {
+        "flake-parts": "flake-parts",
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}
diff --git a/flake.nix b/flake.nix
index dc218f6..17f30dc 100644
--- a/flake.nix
+++ b/flake.nix
@@ -1,93 +1,56 @@
 {
   inputs = {
-    systems.url = "github:nix-systems/default";
-    twist.url = "github:emacs-twist/twist.nix";
-    emacs-ci.url = "github:purcell/nix-emacs-ci";
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    flake-parts.url = "github:hercules-ci/flake-parts";
   };
 
   nixConfig = {
-    extra-substituters = ["https://emacs-ci.cachix.org"];
-    extra-trusted-public-keys = ["emacs-ci.cachix.org-1:B5FVOrxhXXrOL0S+tQ7USrhjMT5iOPH+QN9q0NItom4="];
+    extra-substituters = [ "https://emacs-ci.cachix.org" ];
+    extra-trusted-public-keys = [
+      "emacs-ci.cachix.org-1:B5FVOrxhXXrOL0S+tQ7USrhjMT5iOPH+QN9q0NItom4="
+    ];
   };
 
-  outputs = {
-    systems,
-    nixpkgs,
-    self,
-    ...
-  } @ inputs: let
-    inherit (nixpkgs) lib;
+  outputs =
+    { nixpkgs, flake-parts, ... }@inputs:
+    flake-parts.lib.mkFlake { inherit inputs; } {
+      # Darwin doesn't support all Emacs versions in nix-emacs-ci, so use Linux
+      systems = [
+        "x86_64-linux"
+      ];
 
-    eachSystem = f:
-      nixpkgs.lib.genAttrs (import systems) (
-        system:
-          f (import nixpkgs {
-            inherit system;
-            overlays = [
-              inputs.twist.overlays.default
-            ];
-          })
-      );
+      imports = [
+        inputs.flake-parts.flakeModules.partitions
+      ];
 
-    # Darwin doesn't support all Emacs versions in nix-emacs-ci, so use Linux
-    emacsPackages = inputs.emacs-ci.packages.x86_64-linux;
-  in {
-    data = import ./generated;
+      partitionedAttrs = {
+        packages = "dev";
+        checks = "dev";
+        devShells = "dev";
+      };
 
-    lib.builtinLibrariesOfEmacsVersion = targetVersion: let
-      xs =
-        builtins.map ({libraries, ...}: libraries)
-        (
-          builtins.filter ({version, ...}: version == targetVersion)
-          (builtins.attrValues self.data)
-        );
-    in
-      if builtins.length xs > 0
-      then builtins.head xs
-      else null;
+      partitions = {
+        dev = {
+          extraInputsFlake = ./dev;
+          module = ./dev/flake-module.nix;
+        };
+      };
 
-    devShells = eachSystem (pkgs: {
-      default = pkgs.mkShell {buildInputs = [pkgs.just];};
-    });
+      flake =
+        let
+          data = import ./generated;
+        in
+        {
+          inherit data;
 
-    packages = eachSystem (pkgs: {
-      default = pkgs.linkFarm "default" (
-        [
-          {
-            name = "default.nix";
-            path = pkgs.writeText "emacs-builtins-default-nix" ''{${
-                lib.concatMapStrings (
-                  name: "${name} = import ./${name}.nix;\n"
-                )
-                (builtins.attrNames emacsPackages)
-              }}'';
-          }
-        ]
-        ++ (lib.mapAttrsToList (emacsName: emacsPackage: {
-            name = "${emacsName}.nix";
-            path =
-              pkgs.runCommand "build-${emacsName}-builtins-nix" {
-                buildInputs = [emacsPackage];
-              } ''
-                EMACS_VERSION="$(emacs --version \
-                  | grep -F "GNU Emacs" \
-                  | grep -oE "[[:digit:]]+(:?\.[[:digit:]]+)+")"
-                echo >>$out '{'
-                echo >>$out "  version = \"''${EMACS_VERSION}\";"
-                echo >>$out '  libraries = ['
-                sed -e 's/^/"/' -e 's/$/"/' ${(pkgs.emacsTwist {
-                    inherit emacsPackage;
-                    initFiles = [];
-                    lockDir = null;
-                    inventories = [];
-                  })
-                  .builtinLibraryList} >>$out
-                echo >>$out '  ];'
-                echo >>$out '}'
-              '';
-          })
-          emacsPackages)
-      );
-    });
-  };
+          lib.builtinLibrariesOfEmacsVersion =
+            targetVersion:
+            let
+              xs = builtins.map ({ libraries, ... }: libraries) (
+                builtins.filter ({ version, ... }: version == targetVersion) (builtins.attrValues data)
+              );
+            in
+            if builtins.length xs > 0 then builtins.head xs else null;
+        };
+    };
 }