Leak: Anthropic may ship both Fable 5.5 and Mythos 5.5 next week
VraserX · x · 2026-11-02
A leak suggests Anthropic will release both Fable 5.5 and Mythos 5.5 next week. Evidence cited:
- "Mythos 5.5" appears 6× in an Azure site's HTML (hidden h1 + logo alt text), while visible text still says 5.1;
- Oct 13: claude-fable-5-5 appeared in LiteLLM's Azure price list, removed the next day with "Azure does not list";
- MLflow's Azure model list still shows it: 1M context, $10/$50 pricing, same as 5.1.
The poster notes this could be a rough week for OpenAI — or a massive win depending on how well GPT-6.2 Astra turned out. (Unverified third-party clues.)
More from Models
- SemiAnalysis: safety classifiers sandbag scores of Opus 5.5 and GPT-6 Astra — morqon · 2026-11-02
- Liquid AI's 1.7B LFM3 becomes first local model to nail live fixtures lookup on a MacBook — NielsRogge · 2026-11-02
- Claude upgrade-page traffic rebounded to 17.6M in September, near May's 18.6M peak — firstadopter · 2026-11-02
- Open-source GLiNER-PII scrubs 13 identifiers from a discharge note in 550ms on GPU — MaziyarPanahi · 2026-11-02
- OpenAI Dots user says bloat and broken infra drove him to try newcomer Muse — Koala_Confused · 2026-11-02
- Fable 5.5 reportedly one-shots animation in pure code as Anthropic's coding bet pays off — Hesamation · 2026-11-02