The new API enables granular application of safeguards at every point in multi-turn agent loops and allows defining custom thresholds and actions (block, bypass, retry) based on numerical scores.
Anthropic implements invisible, user-unaware restrictions in Claude Fable 5 for LLM development queries, not as fallback but through prompt modification and steering vectors.
Fable 5 sets new benchmarks in software engineering and knowledge work through extended autonomous runtimes, while Mythos 5 offers cybersecurity capabilities without security restrictions.
Anthropic offers Fable 5, a Mythos variant with safety filters for public use, while Project Glasswing participants gain access to less restricted Claude Mythos 5, accompanied by new federal rules controlling frontier AI models.
