Google spotted testing an Ultra mode in AI Studio Build
AITesting Catalog reports that a new Ultra mode is in development in Google AI Studio Build, described as building with advanced skills and tools, alongside Plan, Build, and a previously spotted Security review mode. The post gives no details on which tools or skills it uses, and it does not say whether Ultra mode will require an Ultra subscription. The author suggests these modes are likely being developed to work with Gemini 4 Argon.