Claude Fable 5 – the first publicly available Mythos-class model

Until now, technology at this level stayed closed due to cybersecurity risks. The longer and more complex the task, the wider the gap from other models.

Example: the new model migrated a 50M-line codebase in a single day instead of two months of work by an entire team 🔥

⚠️ Important! Requests on sensitive topics (egs.: cybersecurity, biology, chemistry) are automatically routed to Claude Opus 4.8.

🌎 Geo-restrictions: Anthropic is unavailable from Russia, Belarus, China, Venezuela, Cuba, Ethiopia, Iran, the DR Congo and a number of other countries.

The Astro proxy infrastructure solution: residential IPs consistently pass Anthropic's anti-fraud checks – unlike datacenter addresses and most VPNs.
▪️ choose country, city and provider across 150 countries;
▪️ controlled IP rotation;
▪️ $3 free test credit via Astro support.