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migration-guidemodels/opus-5-5/migration-guide

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First seen 23 Sep 2026 18:37 UTC

Last changed 24 Sep 2026 17:37 UTC

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24 Sep 26 migration-guide ±changed +2−2 23 Sep 26 migration-guide +new page +1799−0

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Categorymodels
Pathmodels/opus-5-5/migration-guide

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Sections it gained

## What every request to Claude Opus 5.5 must satisfy
## Handle thinking in every response
## Migration checklist by starting model
### Every starting model
### Claude Opus 4.8 or earlier
### Claude Opus 4.7 or earlier
### Claude Opus 4.6 or earlier
### Claude Opus 4.5 or earlier
### Claude 4.1 or earlier
### Claude Sonnet 5 only
## Migrating to Claude Opus 5.5 from Claude Opus 5
### Update your model name