{"version":"2.1.168","anchor":"extended-thinking-budget-for-claude-mythos-preview","canonical_anchor":"extended-thinking-budget-for-claude-mythos-preview","heading":"Extended Thinking Budget for claude-mythos-preview","tier":null,"area":null,"scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.168\/e\/extended-thinking-budget-for-claude-mythos-preview","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.168","markdown":"### Extended Thinking Budget for claude-mythos-preview\n\nClaude Code now enables extended thinking for models in the \"mythos\" family (such as `claude-mythos-preview`) where it was previously disabled. Two distinct thinking budget paths are updated:\n\n- The always-disabled thinking path (`[false, 0]`) now returns `[undefined, 2048]` for mythos-family models, activating thinking with a 2048-token budget.\n- The main thinking configuration path now checks for mythos-family models first and applies a dedicated 2048-token budget constant (`Cx4`) before falling through to the general thinking settings.\n\nThis means users who have `claude-mythos-preview` configured as their model will now benefit from extended reasoning where Claude thinks through problems more carefully before responding.\n\n**Evidence**\n\nModel family detection uses `ZW_ = [\"fruitcake\", \"macaroon\", \"mythos\"]` \u2014 search for `\"mythos\"` in the source; thinking budget is `Cx4 = 2048` (search for `\"Cx4 = 2048\"`)."}