You'll noticeTier: how much it should matter to you
2Useful: my rating, 1 to 5
1Signal: worth watching, 1 to 5
CompactionArea: what it touches
Bug FixesKind: in v2.1.281,
Bug FixesSection of the release
What
/autocompact sets how full the context window gets before Claude Code shrinks the conversation automatically. The context window is how much conversation the model can hold at once. The command and its description now convert the current model name to its standard form before looking up that model's window. A model named by an alias or a variant now gets its model's default window and its upper limit.
Why
If you pick a model by a short name, /autocompact now shows and applies the same window as the full name. As before, CLAUDE_CODE_AUTO_COMPACT_WINDOW overrides the command when it is set.
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.
Confirmed sinceAnthropic's documentation has since written up /autocompact, on Claude Code changelog.* Changed sessions behind a custom `ANTHROPIC_BASE_URL` to use the 1M context window of models that have one (Opus 4.7+, Sonnet 5+, Fable); run `/autocompact 200k` if your gateway stops at 200Kchangelogsee the edit
How sure we are
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agreesAnthropic's documentation has since written up /autocompact, on Claude Code changelog.
