Anthropic released Claude Fable 5, a Mythos-class model with conservative safeguards that excels at long-context reasoning, software engineering, vision, knowledge work, and life-science research. A restricted-lifted variant, Claude Mythos 5, is available to vetted cyberdefense partners under Project Glasswing. Both are priced at $10 per million input tokens and $50 per million output tokens and lead benchmarks across multiple domains.

• Stripe used Fable 5 to migrate a 50-million-line Ruby codebase in one day, a job that would've taken a team two months
• Fable 5 and Mythos 5 cost $10/million input and $50/million output tokens, under half the previous Mythos Preview price
• Mythos 5 matched or beat expert scientists across all protein-engineering steps in a blind test, yielding nine drug candidates now under investigation
• Cybersecurity safeguards on Fable 5 silently reroute sensitive queries to Opus 4.8 in under 5% of sessions, while Mythos 5 drops those restrictions for vetted cyberdefense partners under Project Glasswing