[BUG] OAuth Max plan rate-limited since ~March 24 — 'workspace API usage limits' error on non-API user

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?

Starting March 24, 2026, Claude Code began hitting API Error: Rate limit reached constantly across all sessions. I am on a Max plan using OAuth login only — no ANTHROPIC_API_KEY is set. Usage patterns have not changed.

Parsing local JSONL session logs confirms the onset:

| Date | Rate limit errors |
|------|------------------|
| Mar 16 | 1 (isolated) |
| Mar 17–23 | 0 |
| Mar 24 | 29 |
| Mar 28 | 21 |
| Mar 29 | 30 |

The error message from claude --version returned:

You have reached your specified workspace API usage limits.
You will regain access on 2026-04-01 at 00:00 UTC.

This references "workspace API usage limits" — language specific to API billing, not OAuth subscription limits. This should not apply to an OAuth-only user.

What Should Happen?

Requests should succeed within normal Max plan limits. There was no usage spike — the same multi-session workflow has been running for months without issues.

Actual Behavior

• Rate limit errors appear after 1–2 tool calls per turn, across all sessions simultaneously
• Hits on first message of the day with zero prior usage
• Error references monthly workspace API quota with a reset date (April 1) — wrong quota type for OAuth
• 4–7 concurrent sessions is typical and has never been a problem before March 24

Environment

• Claude Code version: 2.1.87
• OS: Gentoo Linux (kernel 7.0.0-rc5)
• Login method: OAuth (Max plan, long-standing account)
• ANTHROPIC_API_KEY: not set (confirmed via env | grep ANTHROPIC)
• Typical concurrent sessions: 4–7

Related Issues

#40660, #29579, #39581, #38896, #39984, #34786 — those are mostly new/Pro accounts. This report adds evidence from a long-standing Max account with concrete error counts from local logs showing sudden onset on March 24.

🤖 Generated with Claude Code