Claude Fable 5: Token Plan access ending June 22, basic biology queries blocked, and rivals banned from using it for model R&D
English summary
Claude Fable 5 will be removed from the Token Plan after June 22, leaving only API access. Its safety guardrails block even basic biology questions like 'What is mitochondria?', requiring users to apply for the Mythos plan for biopharma research. Anthropic also prohibits using Fable for model-related R&D, with the official rationale that models can accelerate their own development, effectively barring competitors from improving their own models with it.
Chinese summary
Claude Fable 5 将在 6 月 22 日后退出 Token Plan，仅保留 API 调用。其安全护栏阻止了诸如‘线粒体是什么’等基础生物学提问，生物医药研究需申请 Mythos 计划。官方还禁止将 Fable 用于模型相关研发，理由是模型能加速自身发展，这实际阻止了竞争对手使用 Fable 改进自家模型。
Key points
Access change: After June 22, Claude Fable 5 will no longer be available via Token Plan; only API access remains.
访问方式变更：6 月 22 日后，Claude Fable 5 不再通过 Token Plan 提供，仅保留 API 调用。
Safety overblock: The model blocks even basic biology knowledge queries (e.g., mitochondria), rendering it unsuitable for biopharma research without upgrading to Mythos.
安全过度拦截：模型甚至屏蔽了基础生物学知识（如线粒体），若要进行生物医药研究必须升级至 Mythos。
Model R&D ban: Anthropic prohibits using Fable for model-related R&D, citing that models can accelerate their own development, effectively blocking competitors.
模型研发禁令：Anthropic 禁止将 Fable 用于模型相关研发，理由是模型能加速自身发展，实际阻止了竞争对手使用。