[BUG] Context window usage number incorrect after slash commands

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 using the slash comment commands to clear the content (/new) or to compact the current conversation (/compact), the context window usage number shown in the status line does not reset or update correctly.

• Starting a fresh conversation with /new should reset the context window usage back to 100% or a very low number. However, after using this command the context window usage remains the same as before.
• Similarly, using the /compact comment should compact the current conversation and increase the available context, so the usage percentage should go down. In my testing, the number remains unchanged instead of reflecting the additional available context.

This suggests that the context window utilization number is not being updated after these slash commands.

What Should Happen?

After using the /new slash comment to start a new conversation, the context window usage number should reset to reflect the full available context (e.g., close to 0% used or 100% free).

Using the /compact slash comment should compact the current conversation and free up context, so the usage percentage in the status line should decrease accordingly.

In both cases, the context window utilization indicator should update accurately to show the correct context usage after the command is executed.

Error Messages/Logs

Steps to Reproduce

1. Start a conversation and note the context window usage number displayed in the status line.
2. Enter the /new slash comment to clear the content and begin a new conversation.
3. Observe that the context window usage number remains the same as before instead of resetting to show a full context window.
4. In another session, build up a conversation so that the context window usage increases. Then enter the /compact slash comment to compact the conversation.
5. Observe that after compacting, the context window usage percentage does not decrease (i.e., the available context does not increase) and remains unchanged.

Claude Model

Opus

Is this a regression?

No, this never worked

Last Working Version

_No response_

Claude Code Version

2.0.65

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

iTerm2

Additional Information

_No response_