diff --git a/webapp.nix b/webapp.nix
index 177ec21..41ee2e6 100644
--- a/webapp.nix
+++ b/webapp.nix
@@ -15,9 +15,28 @@
 let
   cfg = config.services.webapp;
 
+  # Synthesize a brand kit from `appName` when no explicit brandDir is
+  # provided: take the flake's default logo and overlay a brand.json
+  # carrying the host's app name. This lets existing hosts keep
+  # `services.webapp.appName = "Bouge"` and get "Bouge" in the manifest
+  # WITHOUT needing to author a full brand kit per host. Hosts that DO
+  # author a brand kit (logo, theme colors) supply `brandDir` directly
+  # and `appName` becomes informational.
+  synthesizedBrand = pkgs.runCommand "aio-webapp-brand-${cfg.appName}" {} ''
+    mkdir -p $out
+    cp ${cfg.flake}/branding/default/logo.png $out/logo.png
+    cat > $out/brand.json <<EOF
+    {"name":${builtins.toJSON cfg.appName},"shortName":${builtins.toJSON cfg.appName}}
+    EOF
+  '';
+
+  resolvedBrandDir =
+    if cfg.brandDir != null then cfg.brandDir
+    else synthesizedBrand;
+
   webapp = cfg.flake.lib.mkWebapp {
     inherit pkgs;
-    brandDir = cfg.brandDir;
+    brandDir = resolvedBrandDir;
     extraEnv = {
       ELECTRON_SKIP_BINARY_DOWNLOAD = "1";
       NODE_ENV = "production";
@@ -66,15 +85,29 @@ in {
     };
 
     brandDir = lib.mkOption {
-      type = lib.types.path;
-      default = "${cfg.flake}/branding/default";
-      defaultText = lib.literalExpression ''"\${cfg.flake}/branding/default"'';
+      type = lib.types.nullOr lib.types.path;
+      default = null;
+      example = lib.literalExpression "./../branding/cfaun";
       description = ''
-        Path to the brand kit directory consumed by the build. Defaults
-        to the webapp flake's committed aiolabs brand. Override to a
-        per-host directory in server-deploy (e.g.
-        `./../branding/cfaun`) for per-host logo + manifest name +
-        theme colors. See `branding/README.md` in the webapp repo.
+        Path to the brand kit directory consumed by the build. When
+        null (default), the module synthesizes a kit from `appName` +
+        the flake's default logo — keeps existing hosts working
+        unchanged. Set this to a real brand kit when the host wants its
+        own logo + manifest theme. See `branding/README.md` in the
+        webapp repo.
+      '';
+    };
+
+    appName = lib.mkOption {
+      type = lib.types.str;
+      default = "AIO";
+      example = "Bouge";
+      description = ''
+        Application name shown in the PWA manifest, browser tab, and
+        home-screen install label. Used as the `brand.name` of a
+        synthesized brand kit when `brandDir` is null. When `brandDir`
+        is set, this option becomes informational only — brand.json
+        wins.
       '';
     };