[BUG] macOS Desktop 1.6608.2 - "Prompt is too long" error triggers persistent "Usage limit reached" state with full quota remaining

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?

Subject: [Bug] macOS Desktop 1.6608.2 - "Prompt is too long"
error triggers persistent "Usage limit reached" state with
full quota remaining

Hi team,

I'm on a Max 20x plan and hit a bug today (May 9, 2026) where
my Claude Code session became completely unusable.

Environment:

• App: Claude Desktop for macOS
• Version: 1.6608.2 (ebf1a1), built 2026-05-08T23:17:27.000Z
• Plan: Max 20x

Repro:

1. Long Claude Code session using Opus 4.7 (Max mode), context

built up over many turns

1. Switched model to Sonnet 4.6 mid-session
2. Got "API Error: Prompt is too long"
3. After this error, the app shows "Usage limit reached" and

the input box is greyed out — even in NEW sessions

Actual usage at the moment of failure (screenshot attached):

• Current session (5h): 13% used
• Weekly all models: 48% used
• Sonnet only: 1% used
• Claude Design: 0% used
• Extra usage: OFF

So the "Usage limit reached" banner is clearly incorrect — I
have ~87% of my session quota and ~52% of my weekly quota
remaining. This appears related to issues #52249 and #56035
where a "Prompt is too long" error corrupts the client-side
limit state.

Request:

1. Please investigate why this error puts the app into a

permanent locked state.

1. Please credit back any quota consumed during the failed

retries today.

Feedback ID / logs: [paste from Help → Send feedback if you have it]

Thanks,
[你的名字]

What Should Happen?

\\\

Error Messages/Logs

Steps to Reproduce

Repro:

1. Long Claude Code session using Opus 4.7 (Max mode), context

built up over many turns

1. Switched model to Sonnet 4.6 mid-session
2. Got "API Error: Prompt is too long"
3. After this error, the app shows "Usage limit reached" and

the input box is greyed out — even in NEW sessions

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

Claude Desktop for macOS

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

<img width="1372" height="871" alt="Image" src="https://github.com/user-attachments/assets/603901df-1725-4e25-9fae-98910850b7ed" />
<img width="1148" height="234" alt="Image" src="https://github.com/user-attachments/assets/d0ff2b83-17b9-42e4-9699-761ff796f90b" />
<img width="1264" height="952" alt="Image" src="https://github.com/user-attachments/assets/c87245d0-655c-4227-b685-02b7f3d4c7e6" />