New Claude Code Hooks: MessageDisplay Event, reloadSkills, and additionalContext on Stop Hooks

Claude Code Docs·high signal

Recent Claude Code changelog entries add a MessageDisplay hook event that lets hooks transform or hide assistant message text as it renders, and let Stop/SubagentStop hooks return hookSpecificOutput.additionalContext to feed Claude guidance and keep the turn going without being flagged as a hook error. SessionStart hooks can now return reloadSkills:true to re-scan skill directories mid-session and set the session title. A new /reload-skills command and auto-loading of plugins in .claude/skills (no marketplace) round it out.