# Claude and OpenAI migration checklist

Check the request parameters, response shape, tool loop, output validation and error handling when moving between model versions. Start with a minimal supported request. Add optional behavior one change at a time so a failure has an identifiable cause.

## Worked example

A migration worksheet can pair each old parameter with its documented replacement, removal or unchanged status. “Unknown” is a valid review result. Do not preserve an old setting simply because the new request still reaches the server.

## Copyable prompt

```text
Review this migration from [OLD MODEL/API/SDK] to [NEW MODEL/API/SDK]. Inputs: [CURRENT REQUEST], [CURRENT RESPONSE HANDLER], [OFFICIAL MIGRATION GUIDE]. Produce a diff table for request parameters, response parsing, tools, structured output and errors. Cite the supplied guide for each provider-specific change. Mark unsupported assumptions as unknown. Propose the smallest regression test for every changed behavior.
```

## Checklist

- Record exact old and new model and SDK versions.
- Run one minimal supported request.
- Add tools and output constraints incrementally.
- Keep a tested rollback path.

## Further reading

[Anthropic: migration guide; verify your target version](https://platform.claude.com/docs/en/models/sonnet-5-5/migration-guide)