Claude Code 2.1.299 adds idle compaction to save your prompt cache
The trigger: ~54 minutes idle, before the one-hour cache resets, so a coffee break stops wiping your context. Plus permission gates and Deno's wind-down.
Copy markdown
Idle compaction ships in today's build
Claude Code 2.1.299 landed today and now auto-compacts a session once it has sat idle for roughly 54 minutes, instead of waiting for you to return to a bloated context. It is the kind of quiet quality-of-life change you only notice when it stops costing you.
Why 54 minutes is the number
The timer sits just inside Anthropic's one-hour prompt-cache window. Compact before the cache expires and you keep reusing cached tokens when you come back, rather than re-sending (and re-paying for) the entire context on a large repo.
Also in 2.1.299: a file-mention mute and tighter permissions
The release reportedly adds CLAUDE_CODE_DISABLE_FILE_MENTIONS to kill the @-file autocomplete, and closes several sandbox and MCP permission gaps. If you run Claude Code in CI or lock it down for a team, re-check your permission config after upgrading.
Meanwhile: Cloudflare bought Deno — start the migration clock
Cloudflare acquired Deno and its team on Oct 9. Deno Deploy shuts down about six months out, the standalone runtime gets one more year of security-only updates before development ends, and the JSR registry keeps running. If you ship on Deno Deploy, plan the move now; the runtime stays MIT-licensed for anyone who wants to fork it.
Meanwhile: OpenAI's 722-paper math repo is open to inspect
github.com/openai/math is public under Apache-2.0: 719 manuscripts (after three withdrawals) from an unreleased model, about 42% with Lean formalizations. Worth a caveat before you cite it — Lean confirms a proof follows its stated assumptions, not that the statement matches the real theorem, and many results are still unverified.