Astra's Quiet Wins: Cached Reasoning Swaps, Cross-Window Notes & a Twitter Clone in Minecraft

The first full weekend with GPT-6 Astra in everyone's hands, and the interesting findings are the unglamorous ones nobody put in a launch video. You can now change reasoning effort mid-conversation without invalidating the prompt cache , because the effort change is appended to the end of the context instead of rewriting the top. Codex has an experimental compaction mode where Astra keeps notes across context windows and can search earlier windows including tool calls, off by default and buried in a TOML flag. The hallucination-rate drop is on pages 20 and 21 of the system card and OpenAI barely mentioned it. Third parties are filling in the