Context Editing

In depth

A beta Claude API feature that automatically clears stale content from a conversation server-side before it reaches the model, while your client keeps the full history. The clear_tool_uses_20250919 strategy replaces the oldest tool results with placeholders once input passes a trigger (100,000 tokens by default) and keeps the three most recent, while clear_thinking_20251015 prunes thinking blocks from earlier turns. It keeps long agent loops under the context limit, though clearing tool results invalidates the prompt cache from that point.

Primary source: platform.claude.com