diff --git a/flake.lock b/flake.lock
index a7ae76e..99c5d34 100755
--- a/flake.lock
+++ b/flake.lock
@@ -80,6 +80,27 @@
       }
     },
     "flake-parts": {
+      "inputs": {
+        "nixpkgs-lib": [
+          "nur",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1733312601,
+        "narHash": "sha256-4pDvzqnegAfRkPwO3wmwBhVi/Sye1mzps0zHWYnP88c=",
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "rev": "205b12d8b7cd4802fbcb8e8ef6a0f1408781a4f9",
+        "type": "github"
+      },
+      "original": {
+        "owner": "hercules-ci",
+        "repo": "flake-parts",
+        "type": "github"
+      }
+    },
+    "flake-parts_2": {
       "inputs": {
         "nixpkgs-lib": "nixpkgs-lib"
       },
@@ -135,11 +156,11 @@
         "nixpkgs": "nixpkgs_3"
       },
       "locked": {
-        "lastModified": 1736441698,
-        "narHash": "sha256-0CpZ8xp6C9/k3KVul1xhsVOnPyYZ3OWp/6sA8WGOWM4=",
+        "lastModified": 1741376022,
+        "narHash": "sha256-EPMhteiZurPFiVs1ioBtiUgUMih52w3IwOWLV0hoX1w=",
         "owner": "msyds",
         "repo": "home-manager",
-        "rev": "71be4c32c349f3ea85cdfbe0f21c44357644fc91",
+        "rev": "7b87c2d8b9ad72e83402f8fc6dde24e76b28ee67",
         "type": "github"
       },
       "original": {
@@ -222,7 +243,7 @@
     },
     "nix-fetcher-data": {
       "inputs": {
-        "flake-parts": "flake-parts",
+        "flake-parts": "flake-parts_2",
         "nixpkgs": [
           "sydnix-cli",
           "clj-nix",
@@ -304,11 +325,11 @@
     },
     "nixpkgs_3": {
       "locked": {
-        "lastModified": 1736012469,
-        "narHash": "sha256-/qlNWm/IEVVH7GfgAIyP6EsVZI6zjAx1cV5zNyrs+rI=",
+        "lastModified": 1741010256,
+        "narHash": "sha256-WZNlK/KX7Sni0RyqLSqLPbK8k08Kq7H7RijPJbq9KHM=",
         "owner": "NixOS",
         "repo": "nixpkgs",
-        "rev": "8f3e1f807051e32d8c95cd12b9b421623850a34d",
+        "rev": "ba487dbc9d04e0634c64e3b1f0d25839a0a68246",
         "type": "github"
       },
       "original": {
@@ -398,6 +419,28 @@
         "type": "github"
       }
     },
+    "nur": {
+      "inputs": {
+        "flake-parts": "flake-parts",
+        "nixpkgs": [
+          "nixpkgs"
+        ],
+        "treefmt-nix": "treefmt-nix"
+      },
+      "locked": {
+        "lastModified": 1741373419,
+        "narHash": "sha256-RkLmZob4GnlKntjO26io6wf6haE24pcTr3jAljMJ45c=",
+        "owner": "nix-community",
+        "repo": "NUR",
+        "rev": "4463e6382eca077dbd3c74ae336aef516221b4fc",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-community",
+        "repo": "NUR",
+        "type": "github"
+      }
+    },
     "root": {
       "inputs": {
         "copyparty": "copyparty",
@@ -406,6 +449,7 @@
         "impermanence": "impermanence",
         "niri": "niri",
         "nixpkgs": "nixpkgs_5",
+        "nur": "nur",
         "sops-nix": "sops-nix",
         "sydnix-cli": "sydnix-cli"
       }
@@ -460,6 +504,27 @@
         "type": "github"
       }
     },
+    "treefmt-nix": {
+      "inputs": {
+        "nixpkgs": [
+          "nur",
+          "nixpkgs"
+        ]
+      },
+      "locked": {
+        "lastModified": 1733222881,
+        "narHash": "sha256-JIPcz1PrpXUCbaccEnrcUS8jjEb/1vJbZz5KkobyFdM=",
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "rev": "49717b5af6f80172275d47a418c9719a31a78b53",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "treefmt-nix",
+        "type": "github"
+      }
+    },
     "xwayland-satellite-stable": {
       "flake": false,
       "locked": {
diff --git a/flake.nix b/flake.nix
index 628b133..d685333 100755
--- a/flake.nix
+++ b/flake.nix
@@ -12,6 +12,11 @@
     sops-nix.url = "github:Mic92/sops-nix";
     sydnix-cli.url = "path:///persist/dots/scripts/sydnix-cli";
     copyparty.url = "github:9001/copyparty";
+    # Used for Firefox extensions/addons.
+    nur = {
+      url = "github:nix-community/NUR";
+      inputs.nixpkgs.follows = "nixpkgs";
+    };
   };
 
   outputs = { nixpkgs, ... }@inputs:
diff --git a/users/crumb/programs/firefox.nix b/users/crumb/programs/firefox.nix
new file mode 100644
index 0000000..6c8bf08
--- /dev/null
+++ b/users/crumb/programs/firefox.nix
@@ -0,0 +1,122 @@
+{ config, lib, pkgs, inputs, ... }@args:
+
+let
+  pkgs' = import inputs.nixpkgs {
+    system = args.system;
+    overlays = [ inputs.nur.overlays.default ];
+  };
+in {
+  programs.firefox = {
+    enable = true;
+
+    # Available language codes can be found on the releases page:
+    # https://releases.mozilla.org/pub/firefox/releases/134.0.2/linux-x86_64/xpi/.
+    # The string `134.0.2` may be substituted for any other Firefox release
+    # number.
+    languagePacks = [
+      "en-US"
+      "en-GB"
+    ];
+
+    # Available options can be found at https://mozilla.github.io/policy-templates/.
+    policies = {
+      DisableTelemetry = true;
+      DisableFirefoxStudies = false;
+      EnableTrackingProtection = {
+        Value = true;
+        Locked = true;
+        Cryptomining = true;
+        Fingerprinting = true;
+      };
+      # Weird advertiser shit.
+      FirefoxSuggest = {
+        WebSuggestions = false;
+        SponsoredSuggestions = false;
+        ImproveSuggest = false;
+        Locked = false;
+      };
+      # Weird advertiser shit.
+      DisablePocket = true;
+      DisableFirefoxAccounts = true;
+      DisableAccounts = true;
+      # Firefox has an in-built screenshot tool that I do not need.
+      DisableFirefoxScreenshots = true;
+      # Disable pop-up windows that appear after installation and updates.
+      OverrideFirstRunPage = "";
+      OverridePostUpdatePage = "";
+      # You think you're so important, don't you, Firefox?
+      DontCheckDefaultBrowser = true;
+      # Only tabs not yet visiting a page.  Alternatives: `always`, `never`,
+      # `newtab`.
+      DisplayBookmarksToolbar = "newtab";
+      # Alternatives: `always`, `never`, `default-on`, `default-on`.
+      DisplayMenuBar = "default-off";
+      # Alternative: `unified`, `separate`.
+      SearchBar = "unified";
+    };
+
+    profiles."msyds" = {
+      bookmarks = [];
+
+      # Check about:support for extension/add-on ID strings.
+      extensions = {
+        # Override non-declared settings.
+        force = true;
+        packages = with pkgs'.nur.repos.rycee.firefox-addons; [
+          ublock-origin
+          darkreader
+          privacy-badger
+          vimium
+          kagi-search
+          duckduckgo-privacy-essentials
+          edit-with-emacs
+          copy-as-org-mode
+          clearurls
+        ];
+      };
+
+      search = {
+        # Override non-declared settings.
+        force = true;
+        # Precedence of search engines.
+        order = [ "Kagi" "DuckDuckGo" ];
+        default = "Kagi";
+        privateDefault = "DuckDuckGo";
+        engines = {
+          "Nixpkgs" = {
+            urls = [{
+              template = "https://search.nixos.org/packages";
+              params = [
+                { name = "type"; value = "packages"; }
+                { name = "query"; value = "{searchTerms}"; }
+              ];
+            }];
+            icon =
+              "${pkgs.nixos-icons}/share/icons/hicolor/scalable/apps/nix-snowflake.svg";
+            definedAliases = [ "!np" ];
+          };
+        };
+      };
+
+      # See `about:config` in Firefox for available settings.
+      settings = {
+        # Disable suggestions.
+        "browser.search.suggest.enabled" = false;
+        # Enable dark theme for non-website UI; the URL bar and such.
+        "extensions.activeThemeID" = "firefox-compact-dark@mozilla.org";
+        "browser.theme.content-theme" = 0;
+        "browser.theme.toolbar-theme" = 0;
+        # Disable sponsored suggestions.
+        "browser.newtabpage.activity-stream.showSponsoredTopSites" = false;
+        "browser.newtabpage.activity-stream.system.showSponsored" = false;
+        "browser.newtabpage.activity-stream.showSponsored" = false;
+        "browser.urlbar.sponsoredTopSites" = false;
+        "services.sync.prefs.sync.browser.newtabpage.activity-stream.showSponsored"
+          = false;
+        "services.sync.prefs.sync.browser.newtabpage.activity-stream.showSponsoredTopSites"
+          = false;
+      };
+    };
+  };
+}
+