Cognition announced Claude Fable 5.1 in Devin. With Anthropic’s cache pricing change, Fable-level intelligence is about 54% cheaper—even undercutting Opus. Devin’s Fusion harness matches Fable 5.1 on FrontierCode at roughly 47% lower cost, folding the new model into production agent workflows.
Key Takeaways
- ✓Devin now runs Claude Fable 5.1 for coding agents.
- ✓Cache pricing makes Fable-class capability ~54% cheaper, undercutting Opus on cost.
- ✓Fusion matches Fable 5.1 on FrontierCode at ~47% lower cost for scaled agent runs.