Anthropic brings back Fable 5 after U.S. restrictions, but users are not happy

Anthropic has restored access to Claude Fable 5 after the U.S. Department of Commerce lifted export restrictions on the company's most advanced AI models, Claude Fable 5 and Claude Mythos 5.

The restrictions were introduced on June 12, forcing Anthropic to block access to both models for all non-U.S. citizens, including its own employees who did not hold U.S. citizenship. Because the company had no practical way to verify users' citizenship in real time, it temporarily disabled the models for everyone.

The decision followed a report from Amazon researchers, who demonstrated a technique for bypassing Fable 5's safety mechanisms. Using the method, the model was able to identify software vulnerabilities and, in one case, generate proof-of-concept exploit code. Anthropic tested the same prompts against Claude Opus 4.8, GPT-5.5, and Kimi K2.7, finding that all of them identified the same vulnerabilities.

The company then trained a new request classifier designed to block the jailbreak technique described in the report in more than 99% of cases.

On June 26, U.S. authorities allowed Anthropic to restore Mythos 5 for a limited group of American organizations participating in the Glasswing program. Fable 5 has now returned to Claude Platform, Claude.ai, Claude Code, and Claude Cowork.

The return has not gone over smoothly with users. Fable 5 is available to subscribers on Pro, Max, Team, and some Enterprise plans at no additional cost only until July 7, and only within 50% of their weekly usage limit. After that, continued access will require paid usage credits.

Pricing is a major source of frustration. Fable 5 costs $10 per million input tokens and $50 per million output tokens, making it twice as expensive as Opus 4.8 and roughly five times more expensive than Sonnet 5. It is now the most expensive model in Anthropic’s lineup.

Users are also unhappy about how little time they actually had with the model. Fable 5 was originally expected to be available for two weeks as part of certain subscriptions, but in practice users got closer to ten days: about three days before the restrictions were introduced and seven days after the model returned. The added 50% weekly usage cap only made matters worse.

The shorter access window and tighter limits have drawn criticism across Anthropic-focused communities. Some users say bringing Fable 5 back with reduced availability undermines the point of restoring access at all. Others note that what was billed as a two-week trial ended up feeling like a brief preview followed by a constrained one-week return.

There has also been confusion over Anthropic’s decision to route some routine tasks, including programming and debugging, to the less powerful Claude Opus 4.8 instead of Fable 5.