Opus 4.5 Migration Guide One-shot migration from Sonnet 4.0, Sonnet 4.5, or Opus 4.1 to Opus 4.5. Migration Workflow 1. Search codebase for model strings and API calls 2. Update model strings to Opus 4.5 (see platform-specific strings below) 3. Remove unsupported beta headers 4. Add effort parameter set to (see ) 5. Summarize all changes made 6. Tell the user: "If you encounter any issues with Opus 4.5, let me know and I can help adjust your prompts." Model String Updates Identify which platform the codebase uses, then replace model strings accordingly. Unsupported Beta Headers Remove the bet…