Anthropic's developer account said Claude Fable 5.1 is live in Claude Code and on the Claude Platform at the same list price as Fable 5 with 75% cheaper API cache reads. In the same thread it reported Terminal-Bench 4.0 scores in Claude Code: Fable 5.1 at 55.8%, ahead of Fable 5 at 42% and Opus 5 at 52.3%, and said it leads both on agentic coding and computer-use evals.
Key Takeaways
- ✓Fable 5.1 is selectable in Claude Code and on the Claude Platform as claude-fable-5-1.
- ✓Terminal-Bench 4.0 in Claude Code: Fable 5.1 55.8% vs Fable 5 42% and Opus 5 52.3%.
- ✓Cache reads are 75% cheaper; long API-billed sessions can net about 25%–45% less, with an updated prompting guide and claude-api skill.