Claude Opus 4 5 Migration

Handles the grunt work of migrating your codebase from Sonnet 4.0, Sonnet 4.5, or Opus 4.1 to Opus 4.5. It searches for model strings across different platforms (Anthropic API, Bedrock, Vertex, Azure), updates them to the correct Opus 4.5 variants, removes unsupported beta headers, and adds the effort parameter. The real value is in the conditional prompt adjustments. It knows about Opus 4.5's quirks like tool overtriggering and over engineering tendencies, but only applies fixes when you actually report those issues rather than blindly changing everything. Use this when you're switching models and want someone else to remember all the platform specific string formats and behavioral gotchas.

skills.sh installs: 308
GitHub stars: 33.2K
last updated: Aug 21, 2026

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Install

$ npx -y skills add davila7/claude-code-templates --skill claude-opus-4-5-migration --agent claude-code

Installs into .claude/skills of the current project.

Files

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

Search codebase for model strings and API calls
Update model strings to Opus 4.5 (see platform-specific strings below)
Remove unsupported beta headers
Add effort parameter set to "high" (see references/effort.md)
Summarize all changes made
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 context-1m-2025-08-07 beta header if present—it is not yet supported with Opus 4.5. Leave a comment noting this:

# Note: 1M context beta (context-1m-2025-08-07) not yet supported with Opus 4.5

Target Model Strings (Opus 4.5)

Platform	Opus 4.5 Model String
Anthropic API (1P)	`claude-opus-4-5-20251101`
AWS Bedrock	`anthropic.claude-opus-4-5-20251101-v1:0`
Google Vertex AI	`claude-opus-4-5@20251101`
Azure AI Foundry	`claude-opus-4-5-20251101`