[BUG] Incorrect Cost Usage calculation when continuing work in a resumed session

Author: walricCreated Sep 18, 2025Updated Jul 31, 2026

Steps to reproduce:

  1. Wait for a fresh 5h session block with no CC usage
  2. Start CC, use /resume command and select CC session that contains enough CC usage
  3. Send a new text with a prompt to CC
  4. Claude-Code-Usage-Monitor will show Cost Usage that is significantly higher that expected

I encountered this bug at least 3 times and decided to create a bug report.

Perhaps resuming old session that had significant amount of CC interaction may somehow confuse Claude-Code-Usage-Monitor to make it think all of the session happened in the current session block.

CC subscription type

Pro

System info:

Windows 11 Claude-Code-Usage-Monitor v3.1.0 Claude Code v1.0.117

I also use ccstatusline tool for CC and it shows more realistic cost usage in such scenarios. So I assume there may be a bug in Claude-Code-Usage-Monitor. I am attaching screenshots of your app and ccstatusline for additional context.

Image

Image

Source: Maciek-roboblog/Claude-Code-Usage-Monitor