{"name":"claude-opus-4-8","slug":"claude-opus-4-8","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":"2.1.197","released_at":"2026-06-30 13:31:18","spans":8}},"aliases":[],"entries":[{"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":"refusal-fallback-now-has-its-own-route-for-claude-sonnet-5-5","heading":"Refused requests on Sonnet 5.5 now fall back to Sonnet 5","line":"When a Sonnet 5.5 request is refused as cyber or frontier_llm, Claude Code now falls back to claude-sonnet-5 instead of an Opus model","released_at":"2026-09-28 17:11:59","reason":"found in this entry's text"},{"version":"2.1.280","anchor":"new-cheaper-cost-table-for-claude-opus-5-5","heading":"New cheaper cost table for claude-opus-5-5","line":"A new, cheaper token-cost tier now applies to the claude-opus-5-5 model id","released_at":"2026-09-22 15:44:39","reason":"found in this entry's text"},{"version":"2.1.280","anchor":"future-model-ids-opus-4-6-opus-4-7-opus-4-8-sonnet-4-6","heading":"Future model IDs (opus-4-6, opus-4-7, opus-4-8, sonnet-4-6) added to model-recency comparison list","line":"Model-recency list gains claude-opus-4-6, claude-sonnet-4-6, claude-opus-4-7 and claude-opus-4-8","released_at":"2026-09-22 15:44:39","reason":"found in this entry's text"},{"version":"2.1.280","anchor":"safety-classification-model-routing-table-gains-a-frontier","heading":"Safety-classification model routing table gains a 'frontier_llm' entry","line":"Safety-classification model routing gains a new 'frontier_llm' category mapped to claude-opus-5","released_at":"2026-09-22 15:44:39","reason":"found in this entry's text"},{"version":"2.1.280","anchor":"mid-conversation-system-opt-out-model-list-simplified-to-a-v","heading":"mid_conversation_system opt-out model list simplified to a version comparator","line":"Mid-conversation system prompt opt-out now uses a version comparison instead of a fixed model-name list","released_at":"2026-09-22 15:44:39","reason":"found in this entry's text"},{"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; existing installs stay pinned","line":"Newly launched models like claude-opus-4-7 and claude-fable-5 stay pinned to a launch effort level unless unpinned, but only on installs that predate this build","released_at":"2026-09-22 15:44:39","reason":"found in this entry's text"},{"version":"2.1.248","anchor":"model-tables-extended-to-opus-4-7-4-8-and-opus-5","heading":"Model tables extended to Opus 4.7, 4.8 and Opus 5","line":"Model tables now list claude-opus-4-7, claude-opus-4-8 and claude-opus-5.","released_at":"2026-08-27 20:35:36","reason":"named in this entry, found in this entry's text"},{"version":"2.1.248","anchor":"per-surface-context-limits-for-claude-sonnet-5","heading":"Per-surface context limits for claude-sonnet-5","line":"Context limits for claude-sonnet-5 are 500,000 on two surfaces and a million elsewhere.","released_at":"2026-08-27 20:35:36","reason":"found in this entry's text"},{"version":"2.1.248","anchor":"unreleased-mythos-and-next-generation-model-ids-in-the-bundl","heading":"Unreleased Mythos and next-generation model ids in the bundled tables","line":"Model tables carry ids for a Mythos preview and a 5-series family, not selectable.","released_at":"2026-08-27 20:35:36","reason":"found in this entry's text"}],"entries_total":25,"docs":[{"source":"api","path":"about-claude\/model-deprecations","title":"model-deprecations","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":"agents-and-tools\/agent-skills\/claude-api-skill","title":"claude-api-skill","documented":false},{"source":"api","path":"agents-and-tools\/tool-use\/advisor-tool","title":"advisor-tool","documented":false},{"source":"api","path":"agents-and-tools\/tool-use\/browser-use-tool","title":"browser-use-tool","documented":false},{"source":"api","path":"agents-and-tools\/tool-use\/code-execution-tool","title":"code-execution-tool","documented":false},{"source":"api","path":"agents-and-tools\/tool-use\/computer-use-tool","title":"computer-use-tool","documented":false},{"source":"api","path":"agents-and-tools\/tool-use\/programmatic-tool-calling","title":"Process results programmatically","documented":false},{"source":"api","path":"agents-and-tools\/tool-use\/tool-search-tool","title":"tool-search-tool","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."}],"url":"https:\/\/changelogs.core-directive.com\/reference\/model\/claude-opus-4-8","family_url":"https:\/\/changelogs.core-directive.com\/reference\/model.json"}