yesterday, anthropic officially unveiled the debut of its new mythos series—claude fable 5—positioned as the most powerful ai model to date. however, even before this highly anticipated new model has been widely deployed, it has triggered compliance alerts within microsoft. according to the verge, due to anthropic’s adjustments to its data retention policy, microsoft has urgently suspended internal use of claude fable 5 by its employees.
although microsoft swiftly made the model available to paying users on github copilot and the foundry platform, it has not yet appeared in the list of models accessible through the employee‑only version of github copilot. meanwhile, other models in the claude series—including claude 3.5 sonnet—remain permitted for normal use, as they continue to adhere to a “zero data retention” policy.
the key point of contention lies in how claude fable 5 operates: its built-in next‑generation safety classification system relies on data retention capabilities, meaning anthropic temporarily stores user inputs and model responses for a standard period of 30 days; if content triggers a violation alert, such data may be retained for up to two years. this change directly challenges microsoft’s stringent requirements regarding corporate data sovereignty and compliance, prompting the legal team to conduct a comprehensive review of the terms, with particular focus on potential risks of exposing customer code, internal directives, and sensitive business information.
notably, anthropic had previously voluntarily delayed the public rollout of the mythos series, citing its extraordinary cyber‑defense and offensive capabilities demonstrated during red‑team testing—capabilities so potent that they could potentially be misused. in response, the company simultaneously introduced enhanced query‑filtering mechanisms, while the accompanying new data‑retention rules have further intensified concerns among enterprise customers about its privacy‑governance framework.
as of now, microsoft has not granted internal access to claude fable 5.
