What is the 'effort' parameter mentioned in the skill?

Opus 4.5 introduces an effort parameter; this skill can set it to 'high' to ensure the model uses its maximum reasoning capability for complex tasks.

What happens to my custom prompts during migration?

The skill primarily updates model strings. It will only suggest prompt adjustments (like softening 'must' to 'should') if you encounter specific behavioral issues like tool overtriggering.

Why does it remove the 1M context beta header?

The 'context-1m-2025-08-07' beta header is currently unsupported in the initial release of Opus 4.5, so the skill removes it to prevent API errors.

Which source models are supported for migration?

This skill supports migration from Claude Sonnet 4.0, Sonnet 4.5, and Opus 4.1. It does not currently support Haiku models.

Does this support AWS Bedrock and Google Vertex AI?

Yes, it includes the specific model string formats required for Anthropic 1P API, AWS Bedrock, Google Vertex AI, and Azure AI Foundry.

Opus 4.5 Migration Assistant

Name: Opus 4.5 Migration Assistant
Author: michelabboud

bymichelabboud

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Developer Tools

Automates the transition of codebases and prompts from legacy Claude models to the latest Claude Opus 4.5 version.

The Opus 4.5 Migration Assistant is a specialized utility designed to streamline the upgrade path from Claude Sonnet 4.0, Sonnet 4.5, and Opus 4.1 to the superior Opus 4.5 model. It identifies and replaces platform-specific model strings across Anthropic API, AWS Bedrock, Google Vertex AI, and Azure AI Foundry while managing deprecated beta headers. The skill goes beyond simple search-and-replace by offering targeted prompt adjustments that mitigate known behavioral shifts in Opus 4.5, such as tool overtriggering, over-engineering, and code exploration issues, ensuring your AI integrations remain performant and cost-effective.

Key Features

01Automatic model string updates for multi-cloud environments (AWS, GCP, Azure, Anthropic)

02Heuristic-based prompt softening to prevent tool overtriggering

031 GitHub stars

04Identification and removal of unsupported context window beta headers

05Optimization snippets to prevent over-engineering and improve code inspection

06Configuration of the new 'high' effort parameter for improved reasoning

Use Cases

01Upgrading enterprise LLM integrations from Sonnet or Opus 4.1 to Opus 4.5

02Standardizing model identifiers across diverse cloud infrastructure deployments

03Refining prompt engineering to match the higher sensitivity of Opus 4.5

What are Skills?·How to Install

Install with 🐟 Skill.Fish

npx skillfish add michelabboud/claude-code claude-opus-4-5-migration

For use in Claude.ai and ChatGPT

Download Skill