{"version":"2.1.295","anchor":"claude-haiku-5-5-added-to-a-model-list-with-medium-default-e","canonical_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","tier":"notice","area":"Models","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.295\/e\/claude-haiku-5-5-added-to-a-model-list-with-medium-default-e","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.295","markdown":"### Haiku 5.5 gets a medium-effort thinking default in a model list\n\nA model list now includes `claude-haiku-5-5` with thinking set to medium effort, and the model appears in more places than before\n\n**Unclear.** It is not stated which feature uses this list or whether a remote setting controls it.\n\n**What**\n\nA list of models in Claude Code now includes an entry for `claude-haiku-5-5` with its thinking set to medium effort. Thinking is the model's step-by-step reasoning before it answers, and effort controls how much reasoning it does. The entry sits next to an existing `claude-fable-5` entry, which uses high effort.\n\nThe model name `claude-haiku-5-5` was already in Claude Code, but it now appears in noticeably more places.\n\n**Why**\n\nWherever this list is used, Haiku 5.5 now starts from a medium level of reasoning rather than having no effort setting.\n\n- Area: Models\n- Names: `claude-haiku-5-5`, `claude-fable-5`\n- Tier: You'll notice\n- Useful: 4\/5\n- Signal: 5\/5\n- Scope: individual\n- Heads-up: no"}