Anthropic added a new "Claude Fable 5.1" model listing and clarified that its Python SDK (v1.0+) now removes deprecated temperature, top_p, and top_k parameters entirely, raising errors if used.

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- Legacy: The model will no longer receive updates and may be deprecated in the future.
- Deprecated: The model is still functional but no longer recommended. Anthropic provides a recommended replacement and assigns a retirement date.
- Retired: The model is no longer available for use. Requests to retired models will fail.
 Deprecated models are likely to be less reliable than active models. Move workloads to active models to maintain the highest level of support and reliability.
Deprecated models are likely to be less reliable than active models. Move workloads to active models to maintain the highest level of support and reliability.
The dates on this page apply to Anthropic-operated platforms: the Claude API, Claude Platform on AWS , and Microsoft Foundry . Partner-operated platforms (Amazon Bedrock and Google Cloud) set their own retirement schedules, so a model's lifecycle status and dates can differ. See the Amazon Bedrock , Amazon Bedrock (Opus 4.6 and earlier) , and Google Cloud model tables.
Migrating to replacements
Once a model is deprecated, migrate all usage to a suitable replacement before the retirement date. Requests to models past the retirement date will fail.
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- Model retirement introduces safety- and model welfare-related risks
At some point, Anthropic hopes to make past models publicly available again. In the meantime, Anthropic has committed to long-term preservation of model weights and other measures to help mitigate these impacts. For more details, see Commitments on Model Deprecation and Preservation .
Model status
 Claude Mythos Preview ( claude-mythos-preview ) is deprecated. To migrate to Claude Mythos 5 ( claude-mythos-5 ), see the migration guide .
Claude Mythos Preview ( claude-mythos-preview ) is deprecated. To migrate to Claude Mythos 5 ( claude-mythos-5 ), see the migration guide .
Current and recently retired models are listed in the following table with their status:
API model name Current state Deprecated Tentative retirement date
claude-fable-5-1 Active N/A Not sooner than September 1, 2027
claude-fable-5 Active N/A Not sooner than June 9, 2027
claude-opus-5 Active N/A Not sooner than July 24, 2027
claude-opus-4-8 Active N/A Not sooner than May 28, 2027
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Deprecation history
All deprecations are listed in the following sections, with the most recent announcements first.
2026-06-05: Claude Opus 4.1 model
 This model was retired August 5, 2026.
This model was retired August 5, 2026.
On June 5, 2026, Anthropic notified developers using Claude Opus 4.1 of its upcoming retirement on the Claude API.
Retirement date Deprecated model Recommended replacement
August 5, 2026 claude-opus-4-1-20250805 claude-opus-4-8
2026-04-14: Claude Sonnet 4 and Claude Opus 4 models
 These models were retired June 15, 2026.
These models were retired June 15, 2026.
On April 14, 2026, Anthropic notified developers using Claude Sonnet 4 and Claude Opus 4 models of their upcoming retirement on the Claude API.
Retirement date Deprecated model Recommended replacement
June 15, 2026 claude-sonnet-4-20250514 claude-sonnet-4-6
June 15, 2026 claude-opus-4-20250514 claude-opus-4-8
2026-02-19: Claude Haiku 3 model
 This model was retired April 20, 2026.
This model was retired April 20, 2026.
On February 19, 2026, Anthropic notified developers using Claude Haiku 3 model of its upcoming retirement on the Claude API.
Retirement date Deprecated model Recommended replacement
April 20, 2026 claude-3-haiku-20240307 claude-haiku-4-5-20251001
2025-12-19: Claude Haiku 3.5 model
 This model was retired February 19, 2026.
This model was retired February 19, 2026.
On December 19, 2025, Anthropic notified developers using Claude Haiku 3.5 model of its upcoming retirement on the Claude API.
Retirement date Deprecated model Recommended replacement
February 19, 2026 claude-3-5-haiku-20241022 claude-haiku-4-5-20251001
2025-10-28: Claude Sonnet 3.7 model
 This model was retired February 19, 2026.
This model was retired February 19, 2026.
On October 28, 2025, Anthropic notified developers using Claude Sonnet 3.7 model of its upcoming retirement on the Claude API.
Retirement date Deprecated model Recommended replacement
February 19, 2026 claude-3-7-sonnet-20250219 claude-sonnet-4-6
2025-08-13: Claude Sonnet 3.5 models
 These models were retired October 28, 2025.
These models were retired October 28, 2025.
On August 13, 2025, Anthropic notified developers using Claude Sonnet 3.5 models of their upcoming retirement.
Retirement date Deprecated model Recommended replacement
October 28, 2025 claude-3-5-sonnet-20240620 claude-sonnet-4-6
October 28, 2025 claude-3-5-sonnet-20241022 claude-sonnet-4-6
2025-06-30: Claude Opus 3 model
 This model was retired January 5, 2026.
This model was retired January 5, 2026.
On June 30, 2025, Anthropic notified developers using Claude Opus 3 model of its upcoming retirement.
Retirement date Deprecated model Recommended replacement
January 5, 2026 claude-3-opus-20240229 claude-opus-4-8
2025-01-21: Claude 2, Claude 2.1, and Claude Sonnet 3 models
 These models were retired July 21, 2025.
These models were retired July 21, 2025.
On January 21, 2025, Anthropic notified developers using Claude 2, Claude 2.1, and Claude Sonnet 3 models of their upcoming retirements.
Retirement date Deprecated model Recommended replacement
July 21, 2025 claude-2.0 claude-opus-4-8
July 21, 2025 claude-2.1 claude-opus-4-8
July 21, 2025 claude-3-sonnet-20240229 claude-sonnet-4-6
2024-09-04: Claude 1 and Instant models
 These models were retired November 6, 2024.
These models were retired November 6, 2024.
On September 4, 2024, Anthropic notified developers using Claude 1 and Instant models of their upcoming retirements.
Retirement date Deprecated model Recommended replacement
November 6, 2024 claude-1.0 claude-haiku-4-5-20251001
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November 6, 2024 claude-instant-1.1 claude-haiku-4-5-20251001
November 6, 2024 claude-instant-1.2 claude-haiku-4-5-20251001
API parameter deprecations
Anthropic occasionally deprecates request parameters that no longer apply to current models. Deprecated parameters remain in the SDK request types so existing code continues to type-check, but their behavior changes per model.
Anthropic occasionally deprecates request parameters that no longer apply to current models. How the API treats a deprecated parameter depends on the model, as the following table shows. Most SDKs keep deprecated parameters in their request types so existing code continues to type-check. The Python SDK (v1.0 and later) removes temperature , top_p , and top_k , so passing them raises a TypeError .
Parameter Status Behavior Recommended replacement
temperature , top_p , top_k Deprecated (Claude Opus 4.7 and later) Returns a 400 error when set to a non-default value on Claude 4.7 and later models and Claude Mythos Preview . Omit and use prompting to guide model behavior.
For migration steps, see the migration guide .
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