What probably matters to youSection of the release
Unclear It is not stated what decides whether the Idle compaction setting appears for you.
What
Compaction is when Claude Code summarizes the earlier part of a long conversation to free up room. Idle compaction does this while your session sits unused. It now has its own setting, idleCompaction:
It appears as "Idle compaction" in /config, near Auto-compact, defaults to true, and is shown only when certain checks pass. The panel also reads where the value was set to decide whether you set it yourself.
After an idle compaction, Claude Code now says "Compacted while idle, before the prompt cache expired", or a one-hour version, followed by "turn off with "idleCompaction": false in settings.json".
The feature still depends on the tengu_sunny_locket flag and CLAUDE_CODE_IDLE_COMPACT_MIN_TOKENS, and a helper now reports whether the mode is compact or compact_on_return. Nothing has been read about tengu_sunny_locket for this release.
Nearby, new helpers hide synced skills whose plugin is turned off and point to the plugin or to /plugin.
Why
If you would rather Claude Code not summarize your conversation while you are away, you can now switch it off in /config or by setting "idleCompaction": false in settings.json.
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Added sinceA small documentation edit on Deploy with MDM touched a line naming /config after this was published.* The update keys `disableAutoUpdates`, `autoUpdaterEnforcementHours`, `updateViaUpdatesHost`, and [`releaseChannel`](/docs/third-party/claude-desktop/configuration#releasechannel).third-party/claude-desktop/mdmsee the edit
Confirmed sinceAnthropic's documentation has since written up /config, on Desktop application.* **If the repository doesn't allow auto-merge**: **Merge when ready** doesn't turn on, so enable auto-merge in your [GitHub repository settings](https://docs.github.com/en/repositories/configuring-branches-and-merges-in-your-repository/co…desktopsee the edit
How sure we are
Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.
The writer flagged doubtIt is not stated what decides whether the Idle compaction setting appears for you.
Anthropic's documentation agreesAnthropic's documentation has since written up /config, on Desktop application.
Anthropic's release notes agreeAdded an Idle compaction row to /config for turning idle compaction off or back on; the notices shown after an idle compaction now say how…
