{"name":"claude-opus-5","slug":"claude-opus-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":"2.1.309","builds":0,"mined_builds":150,"first_cited":{"version":"2.1.219","released_at":"2026-07-24 16:11:49","spans":6}},"aliases":[],"entries":[{"version":"2.1.304","anchor":"model-catalog-default-for-the-cc-surface-moved-from-claude-o","heading":"Bundled default model changes to Opus 5.5 at medium effort","line":"The model catalog shipped with Claude Code now defaults to claude-opus-5-5 at medium effort instead of claude-opus-5 at high effort","released_at":"2026-10-19 19:47:15","reason":"found in this entry's text"},{"version":"2.1.302","anchor":"claude-opus-5-added-to-a-model-list","heading":"claude-opus-5 joins a model list used in a capability check","line":"Claude Code now lists claude-opus-5 alongside other models in a list that one of its checks looks at","released_at":"2026-10-16 16:48:28","reason":"found in this entry's text"},{"version":"2.1.290","anchor":"medium-and-high-effort-now-map-to-a-different-measured-profi","heading":"\/code-review medium now runs the high-effort recipe on most models","line":"On every model without its own `\/code-review` row, Opus 5.5 included, `medium` now runs the eight-angle high recipe instead of a single pass. `high`, `xhigh` and Opus 5 are unchanged.","released_at":"2026-10-05 18:12:44","reason":"found in this entry's text"},{"version":"2.1.284","anchor":"model-constants-move-to-opus-55-and-sonnet-55","heading":"Claude Code's built-in model list now points to Opus 5.5 and Sonnet 5.5","line":"Claude Code's built-in current models are now 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(`claude-opus-5-5`) replaces Opus 5 in the model picker's Opus slot, with default effort \"medium\" on the `cc` surface","released_at":"2026-09-23 17:01:17","reason":"found in this entry's text"},{"version":"2.1.281","anchor":"bundled-model-catalog-opus-5-quick-select-entry-is-now-o","heading":"Bundled model catalog: 'Opus 5' quick-select entry is now 'Opus 5.5'","line":"In the bundled model catalog, the \"Opus\" quick-select entry now points to Opus 5.5 instead of Opus 5","released_at":"2026-09-23 17:01:17","reason":"found in this entry's text"}],"entries_total":37,"docs":[{"source":"api","path":"about-claude\/model-deprecations","title":"model-deprecations","documented":false},{"source":"api","path":"about-claude\/models\/choosing-a-model","title":"choosing-a-model","documented":false},{"source":"api","path":"about-claude\/models\/migration-guide","title":"Or, for the model with the same capabilities and no access approval requirement:","documented":false},{"source":"api","path":"about-claude\/models\/model-ids-and-versions","title":"model-ids-and-versions","documented":false},{"source":"api","path":"about-claude\/models\/optimizing-for-cost-and-intelligence","title":"optimizing-for-cost-and-intelligence","documented":false},{"source":"api","path":"about-claude\/use-case-guides\/customer-support-chat","title":"customer-support-chat","documented":false},{"source":"api","path":"about-claude\/use-case-guides\/legal-summarization","title":"legal-summarization","documented":false},{"source":"api","path":"agents-and-tools\/agent-skills\/claude-api-skill","title":"claude-api-skill","documented":false},{"source":"api","path":"agents-and-tools\/agent-skills\/quickstart","title":"quickstart","documented":false},{"source":"api","path":"agents-and-tools\/mcp-connector","title":"mcp-connector","documented":false}],"docs_total":12,"gates":[],"related":[{"name":"claude-opus-4-5","slug":"claude-opus-4-5","description":"Writing a file you have not read is now decided locally by model and permissions, not a server flag."},{"name":"claude-opus-4-6","slug":"claude-opus-4-6","description":"Opus 5 is now the default Opus, with a 1M-context option in the model picker."},{"name":"claude-opus-4-7","slug":"claude-opus-4-7","description":"Opus 5 is now the default Opus, with a 1M-context option in the model picker."},{"name":"claude-opus-4-8","slug":"claude-opus-4-8","description":"Opus 5 is now the default Opus, with a 1M-context option in the model picker."},{"name":"claude-opus-5-5","slug":"claude-opus-5-5","description":"New Opus 5.5 model added with a 1M-token context window and its own pricing tier"}],"url":"https:\/\/changelogs.core-directive.com\/reference\/model\/claude-opus-5","family_url":"https:\/\/changelogs.core-directive.com\/reference\/model.json"}