claude-on-amazon-bedrock-legacy changedbuild-with-claude/claude-on-amazon-bedrock-legacy
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149149#### API model IDs
150150
151151<Note>
152 Claude Fable 5.1, Claude Fable 5, Claude Opus 5.5, Claude Opus 5, Claude Sonnet 5.5, Claude Sonnet 5, Claude Haiku 5.5, Claude Opus 4.8, and Claude Opus 4.7 are reachable through `InvokeModel` on `bedrock-runtime`. These requests are served by the same infrastructure as the [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock) endpoint. For the native Messages API request shape and full feature parity, use that page. These models are omitted from the model table on this page because they do not have ARN-versioned model IDs.
152 Claude Fable 5.2, Claude Mythos 5.2, Claude Fable 5.1, Claude Fable 5, Claude Opus 5.5, Claude Opus 5, Claude Sonnet 5.5, Claude Sonnet 5, Claude Haiku 5.5, Claude Opus 4.8, and Claude Opus 4.7 are reachable through `InvokeModel` on `bedrock-runtime`. These requests are served by the same infrastructure as the [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock) endpoint. For the native Messages API request shape and full feature parity, use that page. These models are omitted from the model table on this page because they do not have ARN-versioned model IDs.
153153</Note>
154154
155155Lifecycle terms (Deprecated, Retired) are defined in [Model deprecations](https://platform.claude.com/docs/en/about-claude/model-deprecations). Lifecycle dates on partner-operated platforms are set by the partner and can differ from the Claude API schedule. For the current retirement date of any model on Amazon Bedrock, see [Amazon Bedrock’s model lifecycle page](https://docs.aws.amazon.com/bedrock/latest/userguide/model-lifecycle.html).
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767767The [computer use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/computer-use-tool) and [browser use](https://platform.claude.com/docs/en/agents-and-tools/tool-use/browser-use-tool) toolsets are available through the InvokeModel API for these models:
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769* Claude Fable 5.2
770* Claude Mythos 5.2
769771* Claude Fable 5.1
770772* Claude Fable 5
771773* Claude Opus 5.5
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783785
784786### Mid-conversation system messages on Bedrock
785787
786[Mid-conversation system messages](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages) are available through the InvokeModel API for Claude Fable 5.1, Claude Fable 5, Claude Opus 5.5, Claude Opus 5, Claude Opus 4.8, Claude Sonnet 5.5, and Claude Haiku 5.5. As described in the note under [API model IDs](https://platform.claude.com/docs/en/build-with-claude/claude-on-amazon-bedrock-legacy#api-model-ids), these requests are served by the same infrastructure as the [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock) endpoint. No beta header is required for mid-conversation system messages. This feature is not available on Claude Sonnet 5. Use the top-level `system` field instead. It is not available for the ARN-versioned models in the model table on this page.
788[Mid-conversation system messages](https://platform.claude.com/docs/en/build-with-claude/mid-conversation-system-messages) are available through the InvokeModel API for Claude Fable 5.2, Claude Mythos 5.2, Claude Fable 5.1, Claude Fable 5, Claude Opus 5.5, Claude Opus 5, Claude Opus 4.8, Claude Sonnet 5.5, and Claude Haiku 5.5. As described in the note under [API model IDs](https://platform.claude.com/docs/en/build-with-claude/claude-on-amazon-bedrock-legacy#api-model-ids), these requests are served by the same infrastructure as the [Claude in Amazon Bedrock](https://platform.claude.com/docs/en/build-with-claude/claude-in-amazon-bedrock) endpoint. No beta header is required for mid-conversation system messages. This feature is not available on Claude Sonnet 5. Use the top-level `system` field instead. It is not available for the ARN-versioned models in the model table on this page.
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788A `role: "system"` message can also set `output_config.effort` to [change effort mid-conversation](https://platform.claude.com/docs/en/build-with-claude/effort#change-effort-mid-conversation-beta) on Claude Fable 5.1 and Claude Opus 5.5. This is in beta: add `mid-conversation-output-config-2026-07-01` to the `anthropic_beta` array in the request body. Without that value, or on Claude Fable 5, Claude Opus 5, or Claude Opus 4.8, the request returns a 400 error: `messages.N.output_config: Extra inputs are not permitted`. In the error, `N` is the index of the `system` message in `messages`.
790A `role: "system"` message can also set `output_config.effort` to [change effort mid-conversation](https://platform.claude.com/docs/en/build-with-claude/effort#change-effort-mid-conversation-beta) on Claude Fable 5.2, Claude Mythos 5.2, Claude Fable 5.1, and Claude Opus 5.5. This is in beta: add `mid-conversation-output-config-2026-07-01` to the `anthropic_beta` array in the request body. Without that value, or on Claude Fable 5, Claude Opus 5, or Claude Opus 4.8, the request returns a 400 error: `messages.N.output_config: Extra inputs are not permitted`. In the error, `N` is the index of the `system` message in `messages`.
789791
790792**For Converse API users:** the Converse API accepts system instructions through its top-level [`system` parameter](https://docs.aws.amazon.com/bedrock/latest/APIReference/API_runtime_Converse.html). To add system instructions mid-conversation, use the InvokeModel API.
791793
792794### Context window
793795
794Claude Fable 5.1, Claude Fable 5, Claude Opus 5.5, Claude Opus 5, Claude Opus 4.8, Claude Opus 4.7, Claude Opus 4.6, Claude Sonnet 5.5, Claude Sonnet 5, Claude Sonnet 4.6, and Claude Haiku 5.5 have a [1M-token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) on Amazon Bedrock. Other Claude models, including Sonnet 4.5 (deprecated) and Sonnet 4 (deprecated), have a 200k-token context window.
796Claude Fable 5.2, Claude Mythos 5.2, Claude Fable 5.1, Claude Fable 5, Claude Opus 5.5, Claude Opus 5, Claude Opus 4.8, Claude Opus 4.7, Claude Opus 4.6, Claude Sonnet 5.5, Claude Sonnet 5, Claude Sonnet 4.6, and Claude Haiku 5.5 have a [1M-token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows) on Amazon Bedrock. Other Claude models, including Sonnet 4.5 (deprecated) and Sonnet 4 (deprecated), have a 200k-token context window.
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796798Bedrock limits request payloads to 20 MB. When sending large documents or many images, you might reach this limit before the token limit.
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