diff --git a/hosts/common/programs/firefox/addons.nix b/hosts/common/programs/firefox/addons.nix
index 2c61b37ae..21f19a989 100644
--- a/hosts/common/programs/firefox/addons.nix
+++ b/hosts/common/programs/firefox/addons.nix
@@ -45,7 +45,7 @@ in
         enable = lib.mkDefault false;  #< obsoleted by uBlock Origin annoyances/cookies lists
       };
       kagi-search = {
-        enable = lib.mkDefault false;
+        enable = lib.mkDefault true;
       };
       # open-in-mpv = {
       #   # test: `open-in-mpv 'mpv:///open?url=https://www.youtube.com/watch?v=dQw4w9WgXcQ'`
diff --git a/hosts/common/programs/firefox/default.nix b/hosts/common/programs/firefox/default.nix
index 37d2fc73f..7c896f810 100644
--- a/hosts/common/programs/firefox/default.nix
+++ b/hosts/common/programs/firefox/default.nix
@@ -270,24 +270,37 @@ in
 
     env.BROWSER = "firefox";  # used by misc tools like xdg-email, as fallback
 
-    fs = {
-      ".mozilla/firefox/bookmarks.html".symlink.target = ./bookmarks.html;
+    fs.".mozilla/firefox/bookmarks.html".symlink.target = ./bookmarks.html;
+    # instruct Firefox to put the profile in a predictable directory (so we can do things like persist just it).
+    # XXX: the directory *must* exist, even if empty; Firefox will not create the directory itself.
+    fs.".mozilla/firefox/profiles.ini".symlink.text = ''
+      [Profile0]
+      Name=default
+      IsRelative=1
+      Path=default
+      Default=1
 
-      # instruct Firefox to put the profile in a predictable directory (so we can do things like persist just it).
-      # XXX: the directory *must* exist, even if empty; Firefox will not create the directory itself.
-      ".mozilla/firefox/profiles.ini".symlink.text = ''
-        [Profile0]
-        Name=default
-        IsRelative=1
-        Path=default
-        Default=1
+      [General]
+      StartWithLastProfile=1
+    '';
 
-        [General]
-        StartWithLastProfile=1
-      '';
-
-      ".mozilla/firefox/user.js".symlink.target = ./user.js;
-    };
+    fs.".mozilla/firefox/user.js".symlink.target = ./user.js;
+    fs.".mozilla/firefox/default/search.json.mozlz4".symlink.target = let
+      drv = pkgs.stdenvNoCC.mkDerivation {
+        # Mozilla uses a custom compression scheme for `search.json` because they're ASSHOLES.
+        # seriously, why do you need to compress this 2 KiB file? and then why do you need to INVENT YOUR OWN COMPRESSION FORMAT FOR THAT?
+        # GET YOUR HEAD OUT OF YOUR ASS.
+        name = "search.json.mozlz4";
+        src = ./.;
+        nativeBuildInputs = with pkgs; [ mozlz4a ];
+        buildPhase = ''
+          mozlz4a ./search.json search.json.mozlz4
+        '';
+        installPhase = ''
+          install -D search.json.mozlz4 "$out"/search.json.mozlz4
+        '';
+      };
+    in "${drv}/search.json.mozlz4";
 
     # flush the cache to disk to avoid it taking up too much tmp.
     persist.byPath = let
@@ -298,7 +311,81 @@ in
       ;
     in {
       ".cache/mozilla".store = maybePersist;
-      ".mozilla/firefox/default".store = maybePersist;
+      # storage consumes 80+ MB
+      # the other profile dirs take significantly less; < 20MB total
+      ".mozilla/firefox/default/storage".store = maybePersist;
+      # profile files (.mozilla/firefox/default/...):
+      # - addons.json
+      #   - regenerated on launch
+      # - addonStartup.json.lz4
+      #   - regenerated on next-next launch
+      # - bookmarkbackups/
+      # - bounce-tracking-protection.sqlite
+      #   - recreated on launch
+      # - cert9.db
+      #   - regenerated on launch
+      # - compatibility.ini
+      #   - regenerated on launch
+      # - containers.json
+      #   - regenerated on launch
+      # - content-prefs.sqlite
+      #   - recreated on launch
+      # - cookies.sqlite{,-wal}
+      #   - recreated on launch
+      # - crashes/
+      # - datareporting/
+      # - domain_to_categories.sqlite{,-journal}
+      #   - recreated on launch
+      # - enumerate_devices.txt
+      #   - recreated on launch
+      # - extension-preferences.json
+      #   - NOT recreated, but inconsequential to delete
+      # - extension-settings.json
+      #   - regenerated on launch
+      # - extension-store/
+      # - extension-store-menus/
+      # - extensions/
+      # - extensions.json
+      #   - regenerated on launch
+      # - failover.jsc
+      #   - regenerated on launch
+      # - favicons.sqlite{,-wal}
+      #   - regenerated on launch
+      # - formhistory.sqlite
+      #   - recreated on launch
+      # - handlers.json
+      #   - NOT recreated, but inconsequential to delete
+      # - key4.db
+      #   - recreated on launch
+      # - lock -> ...
+      # - minidumps/
+      # - permissions.sqlite
+      #   - recreated on launch
+      # - pkcs11.txt
+      #   - regenerated on launch
+      # - places.sqlite{,-wal}
+      #   - recreated on launch
+      # - prefs.js
+      #   - recreated on launch
+      # - protections.sqlite
+      #   - recreated on launch
+      # - search.json.mozlz4
+      #   - recreated on launch; loses any customized search engines
+      # - security_state/
+      # - serviceworker.txt
+      #   - NOT recreated, but inconsequential to delete
+      # - sessionCheckpoints.json
+      #   - recreated on launch
+      # - shield-preference-experiments.json
+      #   - NOT recreated, but inconsequential to delete
+      # - storage/
+      # - storage-sync-v2.sqlite
+      #   - recreated on launch
+      # - storage.sqlite
+      # - times.json
+      #   - recreated on launch
+      # - xulstore.json
+      #   - recreated on launch
     };
   };
 }
diff --git a/hosts/common/programs/firefox/search.json b/hosts/common/programs/firefox/search.json
new file mode 100644
index 000000000..2fe897464
--- /dev/null
+++ b/hosts/common/programs/firefox/search.json
@@ -0,0 +1,83 @@
+{
+  "version": 12,
+  "engines": [
+    {
+      "id": "google",
+      "_name": "Google",
+      "_isAppProvided": true,
+      "_metaData": {
+        "order": 1
+      }
+    },
+    {
+      "id": "bing",
+      "_name": "Bing",
+      "_isAppProvided": true,
+      "_metaData": {
+        "order": 2
+      }
+    },
+    {
+      "id": "ddg",
+      "_name": "DuckDuckGo",
+      "_isAppProvided": true,
+      "_metaData": {
+        "order": 3
+      }
+    },
+    {
+      "id": "wikipedia",
+      "_name": "Wikipedia (en)",
+      "_isAppProvided": true,
+      "_metaData": {
+        "order": 4
+      }
+    },
+    {
+      "id": "search@kagi.comdefault",
+      "_name": "Kagi",
+      "_loadPath": "[addon]search@kagi.com",
+      "_iconMapObj": {
+        "16": "moz-extension://8866e489-faf9-4122-a9a4-4845afbc578f/icons/icon_16px.png",
+        "32": "moz-extension://8866e489-faf9-4122-a9a4-4845afbc578f/icons/icon_32px.png",
+        "48": "moz-extension://8866e489-faf9-4122-a9a4-4845afbc578f/icons/favicon-48.png",
+        "180": "moz-extension://8866e489-faf9-4122-a9a4-4845afbc578f/icons/icon_180px.png"
+      },
+      "_metaData": {
+        "order": 5,
+        "loadPathHash": "cvZ7LzXkcfkHdmbuYpDRqhvLSfZPgPO0CxObgIPkYU0="
+      },
+      "_urls": [
+        {
+          "params": [],
+          "rels": [],
+          "template": "https://kagi.com/search?q={searchTerms}"
+        },
+        {
+          "params": [],
+          "rels": [],
+          "template": "https://kagi.com/api/autosuggest?q={searchTerms}",
+          "type": "application/x-suggestions+json"
+        }
+      ],
+      "_orderHint": null,
+      "_telemetryId": null,
+      "_filePath": null,
+      "_definedAliases": [
+        "@kagi"
+      ],
+      "_extensionID": "search@kagi.com"
+    }
+  ],
+  "metaData": {
+    "locale": "en-US",
+    "region": "unknown",
+    "channel": "default",
+    "experiment": "",
+    "distroID": "nixos",
+    "appDefaultEngineId": "google",
+    "useSavedOrder": true,
+    "defaultEngineId": "search@kagi.comdefault",
+    "defaultEngineIdHash": "hrzTeftqb+2F9OI3GYJwG6XAMryJr8Eut/3f90YKv3k="
+  }
+}