[BUG] UI hangs in conversations when using tools, executing slash commands or thinking (INTRODUCED IN VERSION 2.0.50)

[ytzhakov]

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?

Since the last 2.0.50 version, claude code stalls for 1-2 second with almost every tool use (Read/Write/Update/Bash..). The UI hangs until the tool is executed, and executing the tool takes much longer that it used to. UI also hangs when using slash commands as well. So if I try /rewind, /context, /status in the conversation, UI hangs for 3 seconds before executing the slash command. UI also hangs when pasting text (even if the pasted text is only 2 characters long)

The longer the conversation, the worse the stall and UI hangs.

REVERTING CLAUDE CODE VERSTION TO 2.0.49 FIXES THE ISSUE. IT WAS INTRODUCED IN VERSION 2.0.50

What Should Happen?

Claude code should execute tools without UI hangs and with no 1-2 second stall.

Error Messages/Logs

No error logs, no output.
CPU doesnt panic, RAM usage is nominal.

Steps to Reproduce

1. Start a conversation with claude.
2. Have it use tools (Read/Write/Update/Bash...)
3. as the conversation gets longer, the UI hands at every tool call and tool execution is delayed/stalled by 1-2 secs
4. Try executing any slash command (/context, /status...)

Claude Model

Sonnet (default)

Is this a regression?

Yes, this worked in a previous version

Last Working Version

2.0.49

Claude Code Version

2.0.50

Platform

Anthropic API

Operating System

Windows

Terminal/Shell

Windows Terminal

Additional Information

[github-actions[bot]]

Found 3 possible duplicate issues:

1. https://github.com/anthropics/claude-code/issues/10881
2. https://github.com/anthropics/claude-code/issues/7633
3. https://github.com/anthropics/claude-code/issues/1554

This issue will be automatically closed as a duplicate in 3 days.

• If your issue is a duplicate, please close it and 👍 the existing issue instead
• To prevent auto-closure, add a comment or 👎 this comment

🤖 Generated with Claude Code

[ytzhakov]

Found 3 possible duplicate issues:

1. [BUG] Claude Code consistently degrades in performance over long sessions #10881
2. [BUG] "Read" and "Update" tool slow and will stuck main process of claude code. #7633
3. [BUG] Hanging / Freezing in the middle of work - CPU sample attached #1554

This issue will be automatically closed as a duplicate in 3 days.

• If your issue is a duplicate, please close it and 👍 the existing issue instead
• To prevent auto-closure, add a comment or 👎 this comment

🤖 Generated with Claude Code

THIS ISSUE IS NOT A DUPLICATE OF OLDER ISSUES. It was introduced with version 2.0.50

[nudou350]

Same here! gets unusable after a few promps. It freezes and i can barely type.

[ytzhakov]

@nudou350 I reverted to 2.0.49 for now.

[mjt007]

Same here, it is in effect unusable now.

[dwymark]

Ditto, things were great yesterday, now I am back in input latency hell. Last time this happened I had to cancel my pro account because it made the CLI too painful to use. I came back eventually because I found that it had improved (and unfortunately Gemini CLI is still not as good as Claude Code, even though the underlying model is comparable or better.) I support you Anthropic - when it works, Claude Code is far and away the most enjoyable developer tool on the market. Please address this soon.

[github-actions[bot]]

This issue has been inactive for 30 days. If the issue is still occurring, please comment to let us know. Otherwise, this issue will be automatically closed in 30 days for housekeeping purposes.