{"version":"2.1.300","anchor":"autocompact-offer-experiment-tengu-binary-music","canonical_anchor":"autocompact-offer-experiment-tengu-binary-music","heading":"Offer to choose an auto-compact size for 1M-context sessions","tier":"notice","area":"Compaction","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.300\/e\/autocompact-offer-experiment-tengu-binary-music","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.300","markdown":"### Offer to choose an auto-compact size for 1M-context sessions\n\nUsers with a one-million-token context can be offered a choice of when auto-compact kicks in, from 300k to 900k tokens\n\n**What**\n\nThe context window is how much of the conversation the model can hold at once, measured in tokens (small chunks of text). Auto-compact summarises older parts of the conversation to free up space. Users with a one-million-token context window can now be offered a choice of window size for auto-compact, anywhere from 300k to 900k tokens.\n\nThe offer is not made when the size is already set some other way:\n\n- by an environment variable\n\n- by an experiment or a server setting\n\n- because auto-compact is turned off\n\nIt is controlled by `tengu_binary_music`, a setting sent from Anthropic's servers. When the server sends nothing, the offer stays off.\n\n**Why**\n\nThis is a trial of letting people pick when compaction happens in long-context sessions, rather than leaving it fixed.\n\n- Area: Compaction\n- Tier: You'll notice\n- Useful: 3\/5\n- Signal: 2\/5\n- Scope: individual\n- Heads-up: no"}