claude-opus-4-5-migration

To migrate prompts and API code to Claude Opus 4.5, update model strings across supported platforms, remove unsupported beta headers, and add the effort parameter set to high. This ensures your codebase aligns with Opus 4.5 behavior.

Upgrading from Sonnet 4.x to Opus 4.5 requires updating model strings and adjusting prompt behavior. You must also remove unsupported beta headers like context-1m-2025-08-07 and add the effort parameter set to high.

Yes, the Opus 4.5 migration works with AWS Bedrock and Google Vertex AI, as well as the Anthropic API and Azure AI Foundry. It updates model strings across all these supported platforms.

You should remove unsupported beta headers, such as context-1m-2025-08-07, when upgrading to Opus 4.5 because they are no longer supported. The migration process leaves a note in the code where these headers are removed.

The effort parameter is a setting added during migration to Claude Opus 4.5. It must be set to high in your API requests to align with the new model's behavior and ensure optimal performance.

No, you cannot migrate to Claude Opus 4.5 from Haiku 4.5 using this process. The migration explicitly excludes Haiku 4.5 and only supports upgrading from Sonnet 4.x, Sonnet 4.5, and Opus 4.1.