[FEATURE] Async summarization

Preflight Checklist

• [x] I have searched existing requests and this feature hasn't been requested yet
• [x] This is a single feature request (not multiple features)

Problem Statement

The context window getting full and triggering a blocking summarization operation is disruptive to an interactive workflow. Summarization can take O(minutes).

Proposed Solution

What if Claude Code ran summarization in the background, while it continues to work. E.g. if we start summarization with context [A, B, C] and in the meantime D, E are added, then we can end up with context [S, D, E] where S is the summary of A, B, C. By doing this work asynchronously, we avoid blocking on summarization.

Alternative Solutions

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Priority

Medium - Would be very helpful

Feature Category

API and model interactions

Use Case Example

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Additional Context

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