[BUG] [BUG] API Error: Rate limit reached on Max 20x — persistent 12h+, CLI only, chat works fine

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?

Every request to Claude Code CLI immediately returns "API Error: Rate limit reached".

• Plan: Max 20x ($200/month)
• Usage: well under quota
• Duration: 12+ hours, still ongoing
• Both Opus 4.6 and Sonnet 4.6 affected
• Claude.ai web chat works perfectly on the same account, same machine
• No retry-after header provided

This is NOT an API key usage. I'm using subscription-based CLI via macOS terminal.

Terminal output:

hi

⎿ API Error: Rate limit reached

I contacted Fin AI Agent support, but it incorrectly diagnosed this as an API tier (RPM/ITPM) issue. I am not using the API — I'm on subscription CLI access.

Related issues with identical symptoms:

• #29579 (16% usage, rate limited)
• #30723 (30% usage, rate limited)
• #27336 (every command including logout returns rate limit)

What Should Happen?

Claude should respond normally. Usage is well under quota.

Error Messages/Logs

API Error: Rate limit reached

Steps to Reproduce

1. Open terminal on macOS
2. Run: claude
3. Type any message (e.g., "hi")
4. Immediately returns: API Error: Rate limit reached
5. Switch model with: claude --model sonnet
6. Same error
7. Open claude.ai in browser — works fine on same account

Claude Model

Opus

Is this a regression?

Yes, this worked in a previous version

Last Working Version

Was working normally before this issue started (~12 hours ago)

Claude Code Version

v2.1.78

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

• MacBook Pro, Apple Silicon,Apple M3 Pro 18GB RAM
• Screenshots of Fin AI Agent conversation attached (incorrectly diagnosed as API rate limit)

<img width="526" height="885" alt="Image" src="https://github.com/user-attachments/assets/e42c0de7-4a47-4b0c-bc4d-7dd2a65758ce" />
<img width="565" height="915" alt="Image" src="https://github.com/user-attachments/assets/7cd36733-a6c7-4487-a6e6-f8dbc285a926" />
<img width="581" height="939" alt="Image" src="https://github.com/user-attachments/assets/c39f9b42-0dd2-4c45-a9e1-b6ec8e52387d" />

• Identical to known pattern in #29579, #30723, #27336
• Account-level server-side issue: same account on web works, only CLI broken
• Account email: sheltonlx@gmail.com