What
The auto-compact suggestion and the /compact command read DISABLE_COMPACT from the environment each time they are checked, instead of a snapshot taken at startup. Setting or clearing it during a session now changes behaviour immediately.
Details
- Decides whether the context-limit banner offers "/clear to continue" or "/compact or /clear to continue".
- The value goes through a truthiness helper at the point of use.
- Separately, a startup check that read
CInow passes a literal false.
Evidence
/compact or /clear to continue, Context exceeds the ${l}-token limit by ${t} tokens, Free up context by summarizing the conversation so far, process.env.DISABLE_COMPACT
Strings lifted out of the shipped bundle, so the claim above can be checked against them.
Names in the bundleDISABLE_COMPACT/compact
The entry above is what we published on the day. These lines were added later, as Anthropic's own pages caught up, and they sit beside the original rather than replacing it.
Added since
A small documentation edit on whats-new-fable-5-1 touched a line naming /compact after this was published.
To keep thinking valid across a long session, treat the conversation as append-only. Add instructions with a [mid-conversation system message](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages) ([turn-s…models/fable-5-1/whats-new-fable-5-1 see the edit
Confirmed since
Anthropic's documentation has since written up /compact, on Claude Code changelog.
* Fixed the conversation summary produced by `/compact` and auto-compact mangling text that contained `$` sequenceschangelog see the edit
One source agreesOne thing we can check says the same as this entry.
Anthropic's documentation agrees
Anthropic's documentation has since written up /compact, on Claude Code changelog.