Claude Fable 5.5, GPT 6.2 Astra Could Be Right Around the Corner, Leaks Suggest

What it claims

Decrypt reported on 2 November 2026 that Anthropic may be testing Fable 5.5 and Mythos 5.5, and that OpenAI may be testing GPT-6.2 Astra. All evidence comes from X users and from catalog or page-code artifacts. Neither company has confirmed any of it. The current shipped versions it names are Fable 5.1 and Mythos 5.1 (released 1 September 2026), Opus 5.5 (22 September 2026) and GPT-6 Astra (3 September 2026). Anthropic says Opus 5.5 performs at the level of Fable 5.1 on most tasks at a fraction of the price.

Evidence

• Routing reports. On 11 October, the user Chetaslua wrote that Opus 5.5 "is routing to a new model," either Fable 5.5 or a new Opus. Their demo was an animation drawn in JavaScript from two short prompts, taking 2 hours and 27 million tokens at max thinking effort. A second demo by the developer Shikhar was a Spider-Verse-style animation in one HTML file using WebGL, GLSL shaders and 2D Canvas. Shikhar posed it as a question ("Is this Fable 5.5?"), not a finding. Neither demo has a side-by-side baseline.
• LiteLLM entry. An automated LiteLLM update on 13 October added claude-fable-5-5 after Microsoft Azure's catalog listed it as generally available. The entry's price and limits were copied from Fable 5.1. Its notes state that no source gives a price, capability or context limit for Fable 5.5. The entry was later removed.
• Mythos page code. Kim Isenberg ("Chubby") posted a screenshot on 1 November showing "Mythos 5.5" in the HTML of Anthropic's Mythos page. Chetaslua counted six instances, in a hidden headline and in logo alt text. A live check on 2 November showed only Mythos 5.1.
• Codex usage data. TokenGremlin reported on 1 November that gpt-6.2-astra appears as a separate line in Codex usage breakdowns for some accounts, while the model picker still shows GPT-6 Astra. One screenshot showed 19.8% gpt-6.2-astra against 80% gpt-6-astra.

Limits

No price, context length, benchmark or release date exists for either rumored model. The only pricing seen anywhere, in LiteLLM, was a placeholder copied from Fable 5.1. Any cost or limit planning based on that entry has no source. The release timing comes from Isenberg, who predicted GPT-6.2 Astra "very soon, in response to Fable 5.5 and Anthropic's IPO." Anthropic filed for its IPO on 26 October 2026, and SEC rules put the earliest roadshow start at 10 November.