Feature request: Per-message timestamps in Claude Code UI

Feature Request

Is your feature request related to a problem?

When running Claude Code inside a terminal (e.g., tmux), the shell prompt timestamps (from zsh PS1) disappear because Claude Code replaces the shell interface with its own UI. While tmux status bar shows the current time, there's no way to see when each message or interaction occurred within a Claude Code session.

Describe the solution you'd like

Add optional per-message timestamps in Claude Code's interactive UI — similar to how chat applications display timestamps next to each message. For example:

[20:35:24] > user message here
[20:35:30] Claude: response here
[20:36:01] > next user message

This could be toggled via a setting like "showTimestamps": true in .claude/settings.json or a CLI flag like --timestamps.

Describe alternatives you've considered

• tmux status bar: Shows current time but not per-message timestamps
• Status line script: Only shows session-level duration, not individual message times
• Transcript files: Contains timing data but only available for post-hoc analysis, not real-time
• Hooks: Can log timestamps externally but cannot inject them into the UI

Additional context

For long-running sessions, knowing when each interaction happened is valuable for productivity tracking and debugging. This is especially useful when reviewing a session's history within Claude Code.