Claude has released an announcement stating that, due to relevant restrictions by the U.S. government, access to the Fable 5 model will be suspended for all users. New sessions will default to the user's preset default model or Opus 4.8, while any already active Fable 5 sessions will be terminated with an error. Additionally, API requests for Fable 5 on the Claude Platform will also return errors. Developers are advised to migrate their applications and integrations to other Claude models as soon as possible.