{"name":"claude-fable-5","slug":"claude-fable-5","family":"model","title":"Models","noun":"model","description":"Opus 5 is now the default Opus, with a 1M-context option in the model picker.","description_source":"entry","described_by":{"version":"2.1.219","anchor":"opus-5-replaces-opus-4-8-as-the-default-opus-model"},"presence":{"first_seen":null,"removed_in":null,"in_current_build":false,"newest_mined":"2.1.308","builds":0,"mined_builds":149,"first_cited":{"version":"2.1.170","released_at":"2026-06-09 16:15:44","spans":2}},"aliases":[],"entries":[{"version":"2.1.295","anchor":"claude-haiku-5-5-added-to-a-model-list-with-medium-default-e","heading":"Haiku 5.5 gets a medium-effort thinking default in a model list","line":"A model list now includes `claude-haiku-5-5` with thinking set to medium effort, and the model appears in more places than before","released_at":"2026-10-08 18:22:58","reason":"found in this entry's text, named in this entry"},{"version":"2.1.280","anchor":"new-models-are-unpinned-from-launch-time-forced-effort-by-de","heading":"New models are unpinned from launch-time forced effort by default; 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