## Compatibility
The whole hunk
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22title: Compaction that keeps recent turns
33url: https://platform.claude.com/docs/en/build-with-claude/compaction-keep-recent-turns
44description: Summarize the older turns of a conversation with on-demand compaction and send the most recent turns after the summary, word for word.
5featureMetadata:
6 status: beta
7 betaHeader: compact-2026-09-04
8 supportedModels:
9 - claude-fable-5-1
10 - claude-mythos-5-1
11 - claude-fable-5
12 - claude-mythos-5
13 - claude-mythos-preview
14 - claude-opus-5
15 - claude-opus-4-8
16 - claude-opus-4-7
17 - claude-opus-4-6
18 - claude-sonnet-5
19 - claude-sonnet-4-6
20 supportedPlatforms:
21 Claude API: beta
22 Claude Platform on AWS: beta
23 Amazon Bedrock: not available
24 Google Cloud: beta
25 Microsoft Foundry: beta
526---
6
7## Compatibility
8- Status: Beta
9- [Beta header](https://platform.claude.com/docs/en/api/beta-headers): `compact-2026-09-04`
10- Supported models: `claude-fable-5-1`, `claude-mythos-5-1`, `claude-fable-5`, `claude-mythos-5`, `claude-mythos-preview`, `claude-opus-5`, `claude-opus-4-8`, `claude-opus-4-7`, `claude-opus-4-6`, `claude-sonnet-5`, `claude-sonnet-4-6`
11- Platforms: Claude API (beta), Claude Platform on AWS (beta), Microsoft Foundry (beta); not available on Amazon Bedrock, Google Cloud
1227
1328Keep-tail compaction keeps the last few turns of a conversation word for word after the summary. It changes two things in the [compaction loop](https://platform.claude.com/docs/en/build-with-claude/compaction-on-demand#compact-in-a-loop): which messages go into the compaction request, and what you send after the block. Everything in [Continue from the summary](https://platform.claude.com/docs/en/build-with-claude/compaction-on-demand#continue-from-the-summary) applies unchanged.
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