[BUG] Korean IME input delay: characters appear one keystroke behind

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

When typing Korean text in Claude Code, there is a one-character input delay. The character being composed doesn't appear until the next keystroke is pressed.

What Should Happen?

Expected Behavior

• Characters should appear in real-time as they are being composed, similar to how Korean input works in other terminal applications.

Actual Behavior

• Each composed character only appears after the next keystroke, causing a frustrating one-character delay throughout the entire typing experience.

Error Messages/Logs

Steps to Reproduce

Steps to Reproduce

1. Open Claude Code CLI
2. Switch to Korean input method (e.g., macOS default Korean - 2-Set)
3. Try typing "안녕" (annyeong)
4. Observe that:

• Pressing ㅇ → nothing appears
• Pressing ㅏ → ㅇ appears (instead of 아)
• Pressing ㄴ → 아 appears
• Each character is delayed by one keystroke

Claude Model

Sonnet (default)

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.0.74

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

_No response_