Claude Code version 2.1.280 introduces Claude Opus 5.5 as the new default Opus model, featuring a 1M context window and updated pricing. The update also adds mouse wheel support for scrolling lists in fullscreen mode and allows configuration of MCP tool description length limits.
- Added Claude Opus 5.5 (claude-opus-5-5) with $4/$20 per Mtok pricing and $0.20/Mtok cache reads.
- Added CLAUDE_CODE_MAX_MCP_DESCRIPTION_LENGTH environment variable to override the 2,048-character cap on MCP tool descriptions.
- Fixed auto mode retry loops when safety checks decline or fail to answer, implementing backoff logic.
- Resolved issues with symlinked path writes, Ctrl+C handling in dialogs, and invisible character cleanup for Persian and Arabic text.
- Corrected background subagent message loss, session resume crashes from malformed history, and various UI glitches in fullscreen mode.
This release ensures users have access to the latest Opus model capabilities while resolving stability issues related to background agents, session persistence, and interface responsiveness.