{"name":"claude-sonnet-4-5","slug":"claude-sonnet-4-5","family":"model","title":"Models","noun":"model","description":"Writing a file you have not read is now decided locally by model and permissions, not a server flag.","description_source":"entry","described_by":{"version":"2.1.228","anchor":"write-before-read-rule-is-now-decided-locally-not-by-a-remot"},"presence":{"first_seen":null,"removed_in":null,"in_current_build":false,"newest_mined":"2.1.309","builds":0,"mined_builds":150,"first_cited":{"version":"2.1.232","released_at":"2026-08-13 21:30:53","spans":2}},"aliases":[],"entries":[{"version":"2.1.295","anchor":"generalized-upstream-model-routing-validation-proxy-config","heading":"Proxy model-list warnings now cover every provider and catch typos","line":"Warnings about upstream model lists in proxy settings now apply to every provider, accept wildcards, and flag entries that match no usable model","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":"2.1.284","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":"gateway-model-list-advertises-1m-context-support-and-adds-au","heading":"Gateway model list marks 1M-context models, and telemetry export can use Google sign-in","line":"The gateway now flags which models support the 1M context window, and telemetry export gains an `auth.google` option for Google access tokens","released_at":"2026-09-28 17:11:59","reason":"found in this entry's text"},{"version":"2.1.283","anchor":"sonnet-1m-context-availability-check-now-covers-any-sonnet","heading":"The Sonnet 1M-context check now covers full Sonnet model names","line":"Switching to any Sonnet model name ending in [1m] now checks for 1M-context access, except four older Sonnet models","released_at":"2026-09-25 18:46:11","reason":"found in this entry's text"},{"version":"2.1.236","anchor":"anthropic-default-model-sets-the-model-when-nothing-else-doe","heading":"ANTHROPIC_DEFAULT_MODEL sets the model when nothing else does","line":"Set ANTHROPIC_DEFAULT_MODEL and it becomes your model whenever no flag or ANTHROPIC_MODEL applies.","released_at":"2026-08-19 18:45:14","reason":"found in this entry's text"},{"version":"2.1.232","anchor":"the-managed-configuration-schema-and-zod-4-are-bundled-into-","heading":"The managed-configuration schema and Zod 4 are bundled into the CLI","line":"The full Claude Desktop managed-config schema, covering MCP policy and egress limits, is now bundled in.","released_at":"2026-08-13 21:30:53","reason":"found in this entry's text"},{"version":"2.1.228","anchor":"write-before-read-rule-is-now-decided-locally-not-by-a-remot","heading":"Write-before-Read rule is now decided locally, not by a remote flag","line":"Writing a file you have not read is now decided locally by model and permissions, not a server flag.","released_at":"2026-08-11 17:45:45","reason":"found in this entry's text"},{"version":"2.1.201","anchor":"claude-sonnet-5-added-to-model-compatibility-list","heading":"claude-sonnet-5 added to model compatibility list","line":null,"released_at":"2026-07-03 20:52:33","reason":"found in this entry's text"}],"entries_total":14,"docs":[{"source":"api","path":"about-claude\/model-deprecations","title":"model-deprecations","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\/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},{"source":"api","path":"api\/beta\/agents\/create","title":"Create Agent","documented":false},{"source":"api","path":"api\/beta\/agents\/list","title":"List Agents","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-4-5-20250929","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]`."},{"name":"claude-sonnet-4-6","slug":"claude-sonnet-4-6","description":"Context limits for claude-sonnet-5 are 500,000 on two surfaces and a million elsewhere."}],"url":"https:\/\/changelogs.core-directive.com\/reference\/model\/claude-sonnet-4-5","family_url":"https:\/\/changelogs.core-directive.com\/reference\/model.json"}