[BUG] /usage dialogue gives unstable figures

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?

If you run /usage a few times in quick succession, you'll get different results.

Here are two runs, a few seconds apart.

Current week (all models)
  ████████████████████████▌                          49% used
  Resets Jun 29, 10:59am (Europe/London)

  Current week (all models)
  ████████████████▌                                  33% used
  Resets Jun 29, 11am (Europe/London)

What Should Happen?

It should make absolutely no difference how many times I run /usage, the number should only tick up, until a reset.

Error Messages/Logs

Steps to Reproduce

1. Open Claude Code.
2. Run /usage
3. Press escape to close the usage dialog.
4. Repeat steps 2 + 3 until you observe the unstable figures.

Claude Model

_No response_

Is this a regression?

I don't know

Last Working Version

_No response_

Claude Code Version

2.1.156

Platform

Anthropic API

Operating System

Ubuntu/Debian Linux

Terminal/Shell

Other

Additional Information

Reproducible on multiple terminals.