Quoting Claude Opus 5 system prompt

Anthropic released two new artificial intelligence models, Claude Fable 5 and Claude Mythos 5, on June 9, 2026. Just three days later, Anthropic suspended public access to both models to comply with export controls issued by the United States Department of Commerce.

The Department of Commerce lifted these restrictions on June 30, 2026, and Anthropic restored user access to the models the following day on July 1, 2026. Because these events occurred after the training-data cutoff for the AI, Anthropic included specific instructions within the system prompt for Claude Opus 5 to ensure accurate handling of the topic.

Under this system prompt, Claude confirms the suspension and subsequent restoration accurately and matter-of-factly without denying the events. When asked about the export controls, the AI treats the subject like any standard political topic, offering a fair and factual account while directing users to Anthropic's official statement for additional details.

This guidance matters because it prevents the AI from providing incorrect information about its own availability history during a period affected by regulatory changes. When possible, the model checks for newer developments and otherwise advises users to consult the Anthropic website for the latest updates.