{"version":"2.1.314","anchor":"context-window-lookup-falls-back-to-a-second-source","canonical_anchor":"context-window-lookup-falls-back-to-a-second-source","heading":"Context window size lookup now checks a second source","tier":"internal","area":"Models","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.314\/e\/context-window-lookup-falls-back-to-a-second-source","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.314","markdown":"### Context window size lookup now checks a second source\n\nWhen its first source has no answer, Claude Code checks a second one to find a model's context window and whether it has 1M tokens\n\n**Unclear.** It is not clear what the two sources are, so which models now count as 1M-context is unknown.\n\n**What**\n\nA model's context window is the amount of conversation it can hold at once. Claude Code has two checks for it: one returns the window size and one says whether the model has the large 1M-token window. Both now try a second source when the first one has nothing. The 1M check now also returns true when `native_1m` is set. It used to rely on a single stored value.\n\n**Why**\n\nThis may change which models Claude Code treats as having a 1M-token context window.\n\n- Area: Models\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 2\/5\n- Scope: individual\n- Heads-up: no"}