diff --git a/backend/app/controllers/api/v1/youtube_controller.rb b/backend/app/controllers/api/v1/youtube_controller.rb
index 848c68f..5b14107 100644
--- a/backend/app/controllers/api/v1/youtube_controller.rb
+++ b/backend/app/controllers/api/v1/youtube_controller.rb
@@ -1,10 +1,6 @@
 module Api
   module V1
     class YoutubeController < BaseController
-      include ActionController::Cookies
-
-      skip_before_action :authenticate_request!, only: :callback
-
       def authorize
         team = current_user.manageable_teams.find(params[:team_id])
         team.entitlements.assert_can_connect_youtube!
@@ -12,60 +8,6 @@ module Api
         url = Youtube::OauthUrl.build(state: state, redirect_uri: ENV.fetch("YOUTUBE_REDIRECT_URI"))
         render json: { authorization_url: url }
       end
-
-      def callback
-        return redirect_to_oauth_error("Codice OAuth mancante") if params[:code].blank?
-
-        ctx = Youtube::OauthState.verify!(params[:state])
-        tokens = Youtube::OauthExchange.call(params[:code])
-
-        if ctx[:kind] == :platform
-          unless platform_oauth_authorized?(ctx[:admin_id])
-            return redirect_to "#{admin_base_url}/login", alert: "Sessione admin richiesta", allow_other_host: true
-          end
-
-          return render_platform_token(tokens)
-        end
-
-        user = User.find(ctx[:user_id])
-        team = user.manageable_teams.find(ctx[:team_id])
-        cred = team.youtube_credential || team.build_youtube_credential
-        cred.update!(
-          access_token: tokens[:access_token],
-          refresh_token: tokens[:refresh_token] || cred.refresh_token,
-          expires_at: Time.current + tokens[:expires_in].seconds,
-          channel_id: tokens[:channel_id],
-          channel_title: tokens[:channel_title]
-        )
-        redirect_to "#{public_base_url}/teams/#{team.id}/dettagli?youtube=connected", allow_other_host: true
-      rescue ArgumentError, Youtube::BroadcastService::Error => e
-        redirect_to_oauth_error(e.message)
-      end
-
-      private
-
-      def public_base_url
-        MatchLiveTv.app_public_url.chomp("/")
-      end
-
-      def redirect_to_oauth_error(message)
-        redirect_to "#{public_base_url}/prezzi?youtube_error=#{ERB::Util.url_encode(message)}",
-                    allow_other_host: true
-      end
-
-      def render_platform_token(tokens)
-        @refresh_token = tokens[:refresh_token]
-        @channel_title = tokens[:channel_title]
-        render "admin/youtube/platform_token", layout: "admin"
-      end
-
-      def platform_oauth_authorized?(admin_id)
-        session[:admin_account_id].present? && session[:admin_account_id].to_s == admin_id.to_s
-      end
-
-      def admin_base_url
-        "#{public_base_url}/admin"
-      end
     end
   end
 end
diff --git a/backend/app/controllers/youtube_oauth_callback_controller.rb b/backend/app/controllers/youtube_oauth_callback_controller.rb
new file mode 100644
index 0000000..9de6548
--- /dev/null
+++ b/backend/app/controllers/youtube_oauth_callback_controller.rb
@@ -0,0 +1,42 @@
+# Callback OAuth YouTube (HTML). Non usare Api::V1 — ActionController::API non renderizza le view.
+class YoutubeOauthCallbackController < ActionController::Base
+  layout "admin"
+
+  def show
+    return redirect_to_oauth_error("Codice OAuth mancante") if params[:code].blank?
+
+    ctx = Youtube::OauthState.verify!(params[:state])
+    tokens = Youtube::OauthExchange.call(params[:code])
+
+    if ctx[:kind] == :platform
+      @refresh_token = tokens[:refresh_token]
+      @channel_title = tokens[:channel_title]
+      return render "admin/youtube/platform_token"
+    end
+
+    user = User.find(ctx[:user_id])
+    team = user.manageable_teams.find(ctx[:team_id])
+    cred = team.youtube_credential || team.build_youtube_credential
+    cred.update!(
+      access_token: tokens[:access_token],
+      refresh_token: tokens[:refresh_token] || cred.refresh_token,
+      expires_at: Time.current + tokens[:expires_in].seconds,
+      channel_id: tokens[:channel_id],
+      channel_title: tokens[:channel_title]
+    )
+    redirect_to "#{public_base_url}/teams/#{team.id}/dettagli?youtube=connected", allow_other_host: true
+  rescue ArgumentError, Youtube::BroadcastService::Error => e
+    redirect_to_oauth_error(e.message)
+  end
+
+  private
+
+  def public_base_url
+    MatchLiveTv.app_public_url.chomp("/")
+  end
+
+  def redirect_to_oauth_error(message)
+    redirect_to "#{public_base_url}/prezzi?youtube_error=#{ERB::Util.url_encode(message)}",
+                allow_other_host: true
+  end
+end
diff --git a/backend/app/services/youtube/oauth_exchange.rb b/backend/app/services/youtube/oauth_exchange.rb
index 9aab1eb..81158ac 100644
--- a/backend/app/services/youtube/oauth_exchange.rb
+++ b/backend/app/services/youtube/oauth_exchange.rb
@@ -11,7 +11,13 @@ module Youtube
         grant_type: "authorization_code"
       })
       data = JSON.parse(response.body)
-      raise BroadcastService::Error, data["error_description"] if data["error"]
+      if data["error"]
+        msg = data["error_description"].presence || data["error"]
+        if data["error"] == "invalid_grant"
+          msg = "Codice OAuth già usato o scaduto. Riapri /admin/youtube/platform e ripeti il collegamento."
+        end
+        raise BroadcastService::Error, msg
+      end
 
       info = ChannelInfo.fetch(access_token: data["access_token"])
       {
diff --git a/backend/config/routes.rb b/backend/config/routes.rb
index 377267c..2f481a9 100644
--- a/backend/config/routes.rb
+++ b/backend/config/routes.rb
@@ -40,7 +40,7 @@ Rails.application.routes.draw do
         end
       end
 
-      get "youtube/callback", to: "youtube#callback"
+      get "youtube/callback", to: "/youtube_oauth_callback#show"
     end
   end