Compaction is when Claude Code summarizes a long conversation so it fits in the model's working space. Two parts of how it handles trouble have changed:
- When a summary attempt fails because the request was too long for the model, the retry now rebuilds the request from the summary instructions plus extra text for each retry, rather than re-sending older content.
- When Claude Code is counting the remaining attempts and the model's reply contains no summary section, compaction now fails with a reason saying no summary was returned.
In one trimming case, extra text is also added to the request behind a server-controlled setting that falls back to on when the server sends nothing. Readings taken for this site's account and for an anonymous account before this release came back off.
The summary message after compaction can also carry a note about REPL variables that were kept and a report about Remote Control devices.
Retries after an over-long request are more likely to succeed, and an empty reply is now caught as a failure instead of being treated as a valid summary.
tengu_compact_cache_prefix Off in both readingsThe flag server returned off for the account this site reads and for the anonymous baseline. A reading of off cannot rule out a rollout these two readings sit outside of.
This account: off · anonymous baseline: off · compiled default in v2.1.318: on
These values were read against a different version of Claude Code, so treat them as the nearest reading available instead of one taken on this release.
Read once, for one account on one subscription tier, against v2.1.318. It isn't a statement about your account. What a flag value here can and cannot tell you