Claude Code now actively monitors files you've previously read and notifies you of changes:
- Automatic change detection: Files you've read are tracked with timestamps
- Smart diff display: When a watched file changes, Claude shows only the modified portions with context
- Performance optimization: File change checks are batched and run asynchronously
Example: If you read a file and later it's modified externally, Claude will show:
File edited: /path/to/file.js
[Shows relevant changes with line numbers]