Claude Code idle session compaction reduces usage
Claude Code will now compact long-idle sessions before the prompt cache expires (about 1 hour), so when you return to that session later, only the summary needs to be reprocessed rather than the entire conversation. When Pro and Max users resume very long conversations, if doing so would consume a large proportion of the 5-hour limit, they will receive a warning first.
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Coming back to an old session got lighter on your usage.
Claude Code now compacts long idle sessions right before the prompt cache expires (~1h). If you come back to one later, it only has to reprocess the summary instead of the entire conversation.
And on Pro and Max, resuming a really long conversation now gives you a heads-up first if picking it back up would use a big chunk of your 5-hour limit.