[BUG] 21% session usage consumed on session resume with no user input — Pro plan, macOS

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?

Environment

• Plan: Pro ($20/month)
• Organization ID: 4f4dee87-d910-4390-ae54-b64ad23b9243

Actual behavior
Session usage jumped to 21% immediately upon resume, with no user input submitted.

Time of occurrence
April 2, 2026. Outside Anthropic peak hours (5am–11am PT).

Requesting investigation into whether session resume is generating output tokens without user input on Pro plan accounts.

What Should Happen?

Resuming a session should consume only the tokens needed to reload context, not a significant portion of the session limit.

Error Messages/Logs

Steps to Reproduce

On resuming a previous Claude Code session with no user input, 21% of my session limit was immediately consumed before any prompt was submitted.

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.85

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

This matches the behavior documented in issue #38029, where session resume was identified as triggering abnormal token consumption. That issue references a fix described as "improved memory usage and startup time when resuming large sessions." Either the fix did not cover this case or the regression has reappeared in 2.1.85.