migration-guide changedmodels/sonnet-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
10
where the diff opens
First seen
29 Sep 2026
this site's first read of the page
Recorded edits18to this page, all time
The whole hunk
from line 10, old and new numbered
/
from line 10
1010 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.
1111</Note>
1212
13<Tip>
14 **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:
13Let Claude Code migrate your code for you
1514
16 Let Claude Code migrate your code for you
17
18 ```text
19 /claude-api migrate this project to claude-sonnet-5-5
20 ```
21
22 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.
23</Tip>
15```text
16/claude-api migrate this project to claude-sonnet-5-5
17```
2418
2519Claude Sonnet 5.5 has the same prices as Claude Sonnet 5, except for prompt cache reads, which cost $0.10 USD per million tokens, half the Claude Sonnet 5 rate. See [Claude pricing](https://platform.claude.com/docs/en/about-claude/pricing). For its context window and output limits, see the [Claude Sonnet 5.5](https://platform.claude.com/docs/en/models/sonnet-5-5/overview) model page. For features and prompting, see [What's new in Claude Sonnet 5.5](https://platform.claude.com/docs/en/models/sonnet-5-5/whats-new-sonnet-5-5#feature-support) and [Prompting Claude Sonnet 5.5](https://platform.claude.com/docs/en/build-with-claude/prompt-engineering/prompting-claude-sonnet-5-5).
2620
No line in this hunk matches that.