migration-guide changedmodels/opus-5-5/migration-guide
Nearest release: v2.1.311, published 2 hours before this site recorded the change. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
Recorded here
Lines+5added
Lines−11removed
From line
8
where the diff opens
First seen
23 Sep 2026
this site's first read of the page
Recorded edits22to this page, all time
The whole hunk
from line 8, old and new numbered
/
from line 8
88 This guide covers migrating [Messages API](https://platform.claude.com/docs/en/build-with-claude/working-with-messages) code. If you use [Claude Managed Agents](https://platform.claude.com/docs/en/managed-agents/overview), no changes beyond updating the model name are required.
99</Note>
1010
11<Tip>
12 **Automate your migration with the [Claude API skill](https://platform.claude.com/docs/en/agents-and-tools/agent-skills/claude-api-skill#migrating-to-a-newer-claude-model).** It comes bundled with Claude Code and works for any current Claude model as the target:
11Let Claude Code migrate your code for you
1312
14 Let Claude Code migrate your code for you
15
16 ```text
17 /claude-api migrate this project to claude-opus-5-5
18 ```
19
20 The skill applies the model ID swap and, as needed, breaking parameter changes, prefill replacement, and effort calibration for your target model across your code base, then produces a checklist of items to verify manually. It asks you to confirm the migration scope (entire working directory, a subdirectory, or a specific file list) before editing any files. The skill also detects Amazon Bedrock and Claude Platform on AWS clients and adjusts model ID formats and feature changes for those platforms.
21</Tip>
13```text
14/claude-api migrate this project to claude-opus-5-5
15```
2216
2317This page lists the code changes for moving to Claude Opus 5.5 from [Claude Opus 5](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migrating-from-claude-opus-5), [Claude Opus 4.8](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migrating-from-claude-opus-4-8), [Claude Opus 4.7](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migrating-from-claude-opus-47), [Claude Opus 4.6 and earlier Opus models](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migrating-from-claude-opus-46), or [Claude Sonnet 5](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migrating-from-claude-sonnet-5). Every reader needs [What every request to Claude Opus 5.5 must satisfy](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#request-requirements) and [Handle thinking in every response](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#thinking-in-every-response). Then go to the section for your current model: its first sentence names the other sections that apply to you. The [migration checklist](https://platform.claude.com/docs/en/models/opus-5-5/migration-guide#migration-checklist) lists every change by starting model.
2418
No line in this hunk matches that.