#AnthropicReleasesFable5Model

Claude Fable 5 is Anthropic's most powerful publicly available model and the first in its new Mythos tier to be widely accessible. It is primarily aimed at software engineering, knowledge work, long-term tasks, and visual reasoning.
Anthropic reported an 80.3% score on the SWE-Bench Pro benchmark test for real-world software engineering tasks.
The safety controls of this model are more robust than the restricted version of Claude Mythos 5. In some high-risk areas (such as advanced biology or cybersecurity), requests may be blocked or directed to less capable models.
API pricing is $10 per 1 million input tokens and $50 per 1 million output tokens, roughly twice the pricing of Anthropic's early Opus models.
Why this release matters
This release highlights a growing trend among cutting-edge AI labs: increasing capabilities while simultaneously implementing stricter safety measures. Anthropic believes Fable 5 can handle longer, more autonomous workflows than previous public models, but it also introduces mechanisms to intentionally limit certain sensitive capabilities.
Trade-offs
Stronger coding and reasoning performance Higher token costs
Better long-term task execution More aggressive safety restrictions
Public availability Some queries may be redirected or rejected
Strong benchmark results Benchmark dominance does not always directly translate to advantages in every real-world workflow
Overall, this release positions Claude Fable 5 as a high-end, high-capability model aimed at organizations that value its performance in complex engineering and analytical tasks and are willing to pay a significantly higher price for it.