uhooo

README.md

@@ -81,11 +81,8 @@ Then configure it:
       package = helium.packages.${pkgs.system}.helium-widevine;
 
       extensions = [
-        # uBlock Origin — see "Obtaining extensions" below
-        {
-          id = "cjpalhdlnbpafiamejdnhcphjbkeiagm";
-          hash = "sha256-FIbmYVj8cmXce7Vq4h7d2nOjmk4RkCnABmC4y5NDyGk=";
-        }
+        # uBlock Origin
+        { id = "cjpalhdlnbpafiamejdnhcphjbkeiagm"; }
       ];
 
       # Added to the wrapper
@@ -118,7 +115,8 @@ The following options are available under `programs.helium`:
 | :--------------- | :----------------- | :--------------------- | :------------------------------------------------- |
 | `enable`         | boolean            | `false`                | Whether to enable the Helium browser module.       |
 | `package`        | package            | `self.packages.helium` | The helium package to use.                         |
-| `extensions`     | list of submodules | `[]`                   | List of extensions to install `{ id, hash }`.      |
+| `extensions`     | list of submodules | `[]`                   | Extensions to install: `{ id, hash }` (`hash` only needed in `unpacked` mode). |
+| `extensionInstallMode` | `"policy"` or `"unpacked"` | `"policy"` | How extensions are installed — see below.  |
 | `extraFlags`     | list of strings    | `[]`                   | Command line arguments passed to the wrapper.      |
 | `extraPolicies`  | attribute set      | `{}`                   | Raw Chromium policies to apply.                    |
 | `preferences`    | attribute set      | `{}`                   | Json that will be merged into XDG Config.          |
@@ -157,8 +155,33 @@ find all the json keys and values inside the helium browser by typing
 }
 ```
 
+## Extension install modes
+
+`extensionInstallMode = "policy"` (the default) force-installs every entry in
+`extensions` through the `ExtensionInstallForcelist` Chromium policy. The
+browser downloads and installs each extension itself, so:
+
+- the real Web Store ID and signature are kept — native messaging hosts such as
+  KeePassXC-Browser match on that ID and only work this way,
+- the install is recorded in the profile, so each extension's `onInstalled`
+  handler runs once instead of on every launch,
+- extensions keep updating themselves.
+
+This mode needs the NixOS module, which is what writes the policy file into
+`/etc/chromium/policies/managed/`. No `hash` is required.
+
+`extensionInstallMode = "unpacked"` pins the CRXs in the Nix store and hands
+them to the browser with `--load-extension`. It is fully reproducible and needs
+no NixOS module, but Chromium treats command-line extensions as freshly
+installed on every start — every extension re-runs its `onInstalled` handler,
+which for many extensions means a welcome tab on each launch — and it derives
+the extension ID from the load path unless the manifest carries a `key`. Each
+entry needs a `hash` in this mode; see below.
+
 ## Obtaining extensions
 
+Only needed for `extensionInstallMode = "unpacked"`.
+
 > [!WARNING]
 > Be wary that if you are rate-limited that the file will be empty and the build will fail
 

modules/home-manager.nix

@@ -48,14 +48,23 @@ let
         rm -rf $out/_metadata
       '';
 
-  resolvedExtensions = map (spec: {
-    inherit (spec) id;
-    unpacked = unpackExtension { inherit (spec) id hash; };
-  }) cfg.extensions;
+  unpackedMode = cfg.extensionInstallMode == "unpacked";
+
+  resolvedExtensions = lib.optionals unpackedMode (
+    map (spec: {
+      inherit (spec) id;
+      unpacked = unpackExtension { inherit (spec) id hash; };
+    }) cfg.extensions
+  );
+
+  webStoreUpdateUrl = "https://clients2.google.com/service/update2/crx";
 
   policyAttrs = {
     ExtensionInstallAllowlist = map (ext: ext.id) cfg.extensions;
   }
+  // lib.optionalAttrs (!unpackedMode && cfg.extensions != [ ]) {
+    ExtensionInstallForcelist = map (ext: "${ext.id};${webStoreUpdateUrl}") cfg.extensions;
+  }
   // cfg.extraPolicies;
 
   extensionRoot = "${config.xdg.dataHome}/helium/extensions";
@@ -103,12 +112,42 @@ in
         lib.types.submodule {
           options = {
             id = lib.mkOption { type = lib.types.str; };
-            hash = lib.mkOption { type = lib.types.str; };
+            hash = lib.mkOption {
+              type = lib.types.nullOr lib.types.str;
+              default = null;
+              description = ''
+                CRX hash, only needed when extensionInstallMode is "unpacked".
+              '';
+            };
           };
         }
       );
       default = [ ];
     };
+    extensionInstallMode = lib.mkOption {
+      type = lib.types.enum [
+        "policy"
+        "unpacked"
+      ];
+      default = "policy";
+      description = ''
+        How `extensions` reach the browser.
+
+        "policy" force-installs them through the ExtensionInstallForcelist
+        Chromium policy. The browser downloads each extension itself, so the
+        Web Store IDs and signatures are preserved (native messaging hosts
+        such as KeePassXC depend on the real ID), the install is recorded in
+        the profile, and extensions keep updating themselves. Requires the
+        NixOS module so the policy file lands in /etc/chromium/policies.
+
+        "unpacked" pins the CRXs in the Nix store and passes them via
+        --load-extension. It is reproducible and works without the NixOS
+        module, but Chromium treats command-line extensions as freshly
+        installed on every start, which re-fires each extension's onInstalled
+        handler (welcome tabs on every launch), and derives IDs from the load
+        path unless the manifest carries a "key".
+      '';
+    };
     prodversion = lib.mkOption {
       type = lib.types.str;
       default = "151.0.0.0";
@@ -157,6 +196,14 @@ in
   };
 
   config = lib.mkIf cfg.enable {
+    assertions = map (ext: {
+      assertion = ext.hash != null;
+      message = ''
+        programs.helium.extensions."${ext.id}".hash is required when
+        programs.helium.extensionInstallMode = "unpacked".
+      '';
+    }) (lib.optionals unpackedMode cfg.extensions);
+
     home = {
       packages = [
         heliumWithFlags
@@ -165,18 +212,20 @@ in
       ];
 
       activation = {
-        # Refresh the writable copies the --load-extension flag points at. The
-        # tree is rebuilt from scratch so extensions that were removed from the
-        # config, or whose store path changed, do not linger.
-        heliumExtensions = lib.mkIf (resolvedExtensions != [ ]) (
-          lib.hm.dag.entryAfter [ "writeBoundary" ] ''
-            run rm -rf ${lib.escapeShellArg extensionRoot}
-            run mkdir -p ${lib.escapeShellArg extensionRoot}
-            ${lib.concatMapStringsSep "\n" (ext: ''
-              run cp -r ${ext.unpacked} ${lib.escapeShellArg "${extensionRoot}/${ext.id}"}
-            '') resolvedExtensions}
-            run chmod -R u+w ${lib.escapeShellArg extensionRoot}
-          ''
+        heliumExtensions = lib.hm.dag.entryAfter [ "writeBoundary" ] (
+          if resolvedExtensions != [ ] then
+            ''
+              run rm -rf ${lib.escapeShellArg extensionRoot}
+              run mkdir -p ${lib.escapeShellArg extensionRoot}
+              ${lib.concatMapStringsSep "\n" (ext: ''
+                run cp -r ${ext.unpacked} ${lib.escapeShellArg "${extensionRoot}/${ext.id}"}
+              '') resolvedExtensions}
+              run chmod -R u+w ${lib.escapeShellArg extensionRoot}
+            ''
+          else
+            ''
+              run rm -rf ${lib.escapeShellArg extensionRoot}
+            ''
         );
 
         heliumPreferences = lib.mkIf (cfg.preferences != { }) (