claude-opus-4-5-migration

Migrating Claude Sonnet prompts to Opus 4.5 requires replacing existing Anthropic API model strings with Opus 4.5 target identifiers and removing unsupported beta headers like the 1M context beta. This updates model identifiers across AWS Bedrock, Vertex AI, and Azure AI Foundry for application compatibility.

Yes, Opus 4.5 migration supports AWS Bedrock, Google Vertex AI, Azure AI Foundry, and Anthropic 1P API model string updates. It specifically replaces Sonnet 4.0, Sonnet 4.5, and Opus 4.1 source identifiers with the correct Opus 4.5 target strings across these platforms.

When upgrading to Opus 4.5, you must remove unsupported beta headers, specifically including the 1M context beta header. The migration process flags all changed headers and model strings, providing a summary of modifications to ensure the application behaves as expected.

Yes, you can optionally add effort parameter configuration guidance for high effort when migrating to Opus 4.5. This optional adjustment is applied alongside mandatory model string replacements to help tune Opus 4.5 behavior for specific application needs.

To fix prompt behavior issues like tool overtriggering after an Opus 4.5 model update, you can apply targeted prompt snippet fixes. These optional behavior adjustments address over-engineering, code exploration, frontend aesthetic quality, and thinking sensitivity only when explicitly requested.

A key limitation of migrating Claude models to Opus 4.5 is that it explicitly avoids Haiku migrations, focusing only on Sonnet 4.0/4.5 and Opus 4.1 sources. Additionally, optional behavior fixes are only applied when you explicitly request them or report specific issues.