What: Access to Claude Sonnet 4 with an extended 1 million token context window for processing large codebases and documents How to use:
# Select from the model menu
claude /model
# Choose "Sonnet (1M context)" option
# Or set directly
claude /model sonnet[1m]Details:
- Available to eligible organizations only (checked automatically)
- Higher token costs: $6/$22.50 per million tokens (vs $3/$15 for regular Sonnet)
- Automatically selected as default for users with Opus mode and 1M access
- One-time welcome notification explains the feature and rate limit implications
- Access status cached for 1 hour to minimize API calls