claude-opus-4-5-migration

Migrating prompts to Opus 4.5 involves updating model strings (e.g., claude-sonnet-4-20250514 to claude-opus-4-5-20251101), removing unsupported beta headers, adjusting prompts for behavioral differences, and setting the effort parameter to high. This Skill automates these updates across Anthropic API, AWS Bedrock, Google Vertex AI, and Azure AI Foundry.

Opus 4.5 migration replaces old model identifiers from Claude Sonnet 4.0, Sonnet 4.5, and Opus 4.1 with the correct Opus 4.5 identifiers. The Skill enforces model string mapping specific to each platform—Anthropic API, AWS Bedrock, Google Vertex AI, and Azure AI Foundry—ensuring API calls use current model names.

Yes, this migration Skill handles Opus 4.5 updates across four major platforms: Anthropic API, AWS Bedrock, Google Vertex AI, and Azure AI Foundry. It adjusts platform-specific model strings and configurations for each, so your codebase works consistently regardless of deployment target.

Opus 4.5 has known behavioral differences—such as over-triggering of tools or over-engineering solutions—compared to earlier models. The Skill provides specific prompt adjustment guidance and code snippets to fine-tune prompts and prevent these issues, ensuring optimal performance.

The effort parameter is a beta configuration that optimizes Opus 4.5 for either deep reasoning or cost efficiency. This Skill guides you to set effort to high as part of migration, ensuring your model configuration matches your use case and leverages Opus 4.5's full capabilities.

Yes, this Skill migrates both prompts and code simultaneously during codebase updates. It updates all model strings across your implementation, removes unsupported headers, adjusts prompt logic, and generates a migration summary with post-migration guidance for complete modernization.