Explore the context window changedcontext-window
Nearest release: v2.1.284, published under an hour before upstream edited the page. Shown because the two are within 24 hours of each other. Nothing here says the release caused the edit.
Upstream edited this page at 28 Sep 2026 17:53 UTC, give or take a minute or two: the time comes from Anthropic’s own sitemap rather than from a commit. This site recorded the change at 28 Sep 2026 23:37 UTC.
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Recorded edits14to this page, all time
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15901590When a long session compacts, Claude Code summarizes the conversation history to fit the context window. As of v2.1.198, the summarization request inherits your session's [extended thinking](/docs/en/model-config#extended-thinking) configuration, so it reasons with thinking enabled when your session has it enabled and stays off otherwise. Thinking affects only how the summary is produced; your session settings are unchanged afterward. What happens to each kind of content depends on how it was loaded:
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1592| Mechanism | After compaction |
1593| :-------------------------------------------------------------------------------------------------------------------------------------------------------- | :---------------------------------------------------------------------------------------------------- |
1594| System prompt and output style | Both still apply |
1595| Project-root CLAUDE.md and unscoped rules | Re-injected from disk |
1596| Auto memory | Re-injected from disk |
1597| [Git status snapshot](/docs/en/settings-reference#includegitinstructions) | Claude Code reads a fresh one from your repository |
1598| The plan Claude wrote in [plan mode](/docs/en/permission-modes#analyze-before-you-edit-with-plan-mode) | Re-injected from disk |
1599| Rules with `paths:` frontmatter | Claude Code reloads them as Claude reads files they match |
1600| Nested CLAUDE.md in subdirectories | Claude Code reloads them as Claude reads files in that subdirectory |
1601| Files Claude read or edited | Claude Code re-reads up to five, most recently modified first |
1602| Invoked skill bodies | Re-injected, capped at 5,000 tokens per skill and 25,000 tokens total; oldest dropped first |
1592| Mechanism | After compaction |
1593| :- | :- |
1594| System prompt and output style | Both still apply |
1595| Project-root CLAUDE.md and unscoped rules | Re-injected from disk |
1596| Auto memory | Re-injected from disk |
1597| [Git status snapshot](/docs/en/settings-reference#includegitinstructions) | Claude Code reads a fresh one from your repository |
1598| The plan Claude wrote in [plan mode](/docs/en/permission-modes#analyze-before-you-edit-with-plan-mode) | Re-injected from disk |
1599| Rules with `paths:` frontmatter | Claude Code reloads them as Claude reads files they match |
1600| Nested CLAUDE.md in subdirectories | Claude Code reloads them as Claude reads files in that subdirectory |
1601| Files Claude read or edited | Claude Code re-reads up to five, most recently modified first |
1602| Invoked skill bodies | Re-injected, capped at 5,000 tokens per skill and 25,000 tokens total; oldest dropped first |
16031603| [Background commands](/docs/en/interactive-mode#background-bash-commands) and background [subagents](/docs/en/sub-agents#run-subagents-in-foreground-or-background) | Keep running. Claude Code reminds Claude which ones are still running so it doesn't start a duplicate |
1604| Context that hooks added earlier | Summarized with the rest of the conversation |
1605| [SessionStart hooks](/docs/en/hooks-guide#re-inject-context-after-compaction) that match the `compact` source | Claude Code runs them and adds their output to the compacted context |
1604| Context that hooks added earlier | Summarized with the rest of the conversation |
1605| [SessionStart hooks](/docs/en/hooks-guide#re-inject-context-after-compaction) that match the `compact` source | Claude Code runs them and adds their output to the compacted context |
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16071607Right after compaction, Claude Code re-reads up to five of the files Claude has read or edited in the session, choosing the ones modified most recently. A file over 5,000 tokens comes back as a path reference without its content, shown as `Referenced file` instead of `Read`.
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