GPT-6.2 Astra appears in Codex, Anthropic official website code appears Mythos 5.5

On November 1, 2026, multiple users posted on X stating that OpenAI's Codex usage data included a model label named GPT-6.2 Astra, while the model selector still displayed GPT-6 Astra. A usage chart covering October 26 to November 1 showed that gpt-6-astra accounted for 80%, and gpt-6.2-astra accounted for 19.8%. Another account posted a suspected JSON snippet of an API response, with the response.model field being gpt-6.2-astra. According to Quantum Bit, GPT-6.2 Astra has been undergoing a limited gray testing among some users, with access primarily restricted to Pro plan users at $500 per month. Some users reported that about 20% of requests were routed to 6.2, while others claimed all requests pointed to 6.2.

On the same day, an account posted a screenshot claiming that hidden code on the Anthropic official website's Mythos page included Claude Mythos 5.5. The visible page displayed Claude Mythos 5.1, while the hidden header and logo alt text indicated 5.5. According to Quantum Bit, this text briefly appeared in the front-end code of the official website and was removed a few hours later. Anthropic has not confirmed this, and currently, apart from the screenshot, there are no archived copies to verify this change.

Additionally, there were previous reports that Fable 5.5 had appeared in the Microsoft Azure and MLflow directories, with a context window of 1 million tokens and an output limit of 128K tokens. Verification showed that on October 13, 2026, a bot added the entry azure_ai/claude-fable-5-5 to the price list of the open-source tool LiteLLM, which was deleted the next day, with the deletion note stating "Azure did not list this model." These parameters are identical to those of Fable 5.1. As of now, neither OpenAI nor Anthropic has officially released the aforementioned models.