Due to concerns regarding data retention, Microsoft restricts employees from using Claude Fable.

Anthropic launched its first Mythos series AI model, Claude Fable, yesterday, causing concern within Microsoft. According to sources, Microsoft has restricted employees from using Claude Fable 5 because Anthropic updated data retention requirements. Although Microsoft quickly made Claude Fable 5 available to GitHub Copilot and Foundry customers, the model did not appear in the model selection list for Microsoft employees' internal version of GitHub Copilot. Microsoft employees can still use other versions of the Claude model internally, all of which follow zero data retention rules. Microsoft has informed employees that its legal team is evaluating Anthropic's new data retention regulations. The company's main concern is the security of customer data and confidential information. As of now, the legal department has not yet determined whether to approve employees for internal use of Claude Fable.