{"name":"claude-sonnet-4-6","slug":"claude-sonnet-4-6","family":"model","title":"Models","noun":"model","description":"Context limits for claude-sonnet-5 are 500,000 on two surfaces and a million elsewhere.","description_source":"entry","described_by":{"version":"2.1.248","anchor":"per-surface-context-limits-for-claude-sonnet-5"},"presence":{"first_seen":null,"removed_in":null,"in_current_build":false,"newest_mined":"2.1.308","builds":0,"mined_builds":149,"first_cited":{"version":"2.1.195","released_at":"2026-06-26 18:16:23","spans":3}},"aliases":[],"entries":[{"version":"2.1.295","anchor":"sonnet-46-kelp-forest-sonnet-override-skipped-for-some-mode","heading":"A remote override for Sonnet 4.6 no longer applies to some models","line":"A remotely supplied override for `claude-sonnet-4-6` is now skipped for some models that used to receive it","released_at":"2026-10-08 18:22:58","reason":"found in this entry's text"},{"version":"2.1.293","anchor":"haiku-models-no-longer-exempt-from-the-sonnet-default-probe","heading":"Haiku model names now go through the third-party Sonnet default check","line":"On third-party providers, Haiku model names are no longer skipped by the check that sets up the Sonnet default model","released_at":"2026-10-07 17:18:04","reason":"found in this entry's text"},{"version":"2.1.287","anchor":"claude-5-sonnet-model-entry-drops-native-1m-3p-flags","heading":"Sonnet model entries no longer mark Bedrock, Vertex and Foundry as natively 1M","line":"Two Sonnet model entries no longer flag Bedrock, Vertex and Foundry as supporting the 1M-token context window natively","released_at":"2026-10-01 16:59:25","reason":"found in this entry's text"},{"version":"2.1.285","anchor":"claude-sonnet-5-gets-high-effort-thinking-entry-in-model-lis","heading":"Effort picker shows high as Recommended, and claude-sonnet-5 is listed with high effort","line":"The high effort option is now labelled Recommended instead of Default, and the model list includes `claude-sonnet-5` set to high effort","released_at":"2026-09-29 17:32:09","reason":"found in this entry's text"},{"version":"2.1.284","anchor":"sonnet-55-claude-sonnet-5-5-added-and-made-the-default-s","heading":"Sonnet 5.5 added and made the default for the sonnet model name","line":"Sonnet 5.5 (`claude-sonnet-5-5`) is now in the model list and is what `sonnet` picks when using Anthropic directly","released_at":"2026-09-28 17:11:59","reason":"found in this entry's text"},{"version":"2.1.284","anchor":"sonnet-alias-now-resolves-to-sonnet-55-claude-sonnet-5-5","heading":"The sonnet model name now points to Sonnet 5.5 on the Anthropic API","line":"Choosing sonnet now selects Sonnet 5.5 instead of Sonnet 5 on the Anthropic API, while Bedrock, Vertex and other providers keep older models","released_at":"2026-09-28 17:11:59","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 claude-opus-5-5 and claude-sonnet-5-5, with claude-opus-5 and claude-sonnet-5 as the previous ones","released_at":"2026-09-28 17:11:59","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":"2.1.275","anchor":"offlinefallback-model-catalog-switches-ccrccd-default-mode","heading":"Offline\/fallback model catalog switches ccr\/ccd default model from Sonnet 4.6 to claude-opus-5","line":"Fallback model list now defaults 'ccr' and 'ccd' to claude-opus-5 instead of Sonnet 4.6 when the live catalog is unreachable","released_at":"2026-09-17 20:20:31","reason":"found in this entry's text"},{"version":"2.1.268","anchor":"model-family-allowlist-extended-with-placeholder-future-mode","heading":"Model family allowlist extended with placeholder future models","line":"Model list now recognizes placeholder future Claude models like claude-opus-4-6 and claude-sonnet-4-6","released_at":"2026-09-10 18:41:11","reason":"found in this entry's text, named in this entry"}],"entries_total":20,"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\/tool-use\/advisor-tool","title":"advisor-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\/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},{"source":"api","path":"api\/beta","title":"Beta","documented":false},{"source":"api","path":"api\/beta\/agents","title":"Agents","documented":false},{"source":"api","path":"api\/beta\/agents\/archive","title":"Archive Agent","documented":false}],"docs_total":12,"gates":[],"related":[{"name":"claude-sonnet-4-0","slug":"claude-sonnet-4-0","description":"Switching to any Sonnet model name ending in [1m] now checks for 1M-context access, except four older Sonnet models"},{"name":"claude-sonnet-4-5","slug":"claude-sonnet-4-5","description":"Writing a file you have not read is now decided locally by model and permissions, not a server flag."},{"name":"claude-sonnet-4-5-20250929","slug":"claude-sonnet-4-5-20250929","description":"The dated first-party API id of Sonnet 4.5 (`claude-sonnet-4-5` in Claude Code's model table), also used for the `anthropic_aws`, `anthropic_google_cloud` and `gateway` providers. On the first-party provider, when certain account checks pass, a startup migration rewrites a user-settings `model` of `claude-sonnet-4-5-20250929` or `sonnet-4-5-20250929` (with or without `[1m]`) to `sonnet` or `sonnet[1m]`."}],"url":"https:\/\/changelogs.core-directive.com\/reference\/model\/claude-sonnet-4-6","family_url":"https:\/\/changelogs.core-directive.com\/reference\/model.json"}