Anthropic introduced a mandatory 30-day data retention policy for its Claude Fable 5 model, released on June 9, 2026. This policy overrides previous zero data retention agreements for enterprise clients, affecting sectors like finance, law, and healthcare.
Microsoft restricted internal access to the model on June 10, 2026, citing data confidentiality concerns. Additionally, US Commerce Department export controls caused a full suspension of access to the model from June 12 to 13, with service restoration occurring on July 1, 2026.
The retention policy applies exclusively to Mythos-class models. Anthropic stated that stored data is not used for training and is deleted after 30 days unless required for legal or safety reviews.
In August 2026, the company announced Enterprise Frontier Safeguards to allow data management within customer cloud environments, with a rollout planned for fall 2026. On September 1, 2026, Anthropic released version 5.1 to address retention and pricing issues.
