[Bug] Opus 529 overloaded errors on Max 20x during autonomous workflows despite Sonnet succeeding

Bug Description
]# Bug Report Draft — to file via /bug in Claude Code OR email to support@anthropic.com

Filing instructions:

1. Preferred: in your Claude Code terminal, type /bug and paste the block below. Auto-attaches your auth/account/version metadata.
2. Alternative: email the same block to support@anthropic.com from bippal@gmail.com with subject "Max 20x customer — Opus 529 capacity issue (5 request_ids attached)"

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Bug content (copy from here through "---")

TITLE: Max 20x customer hitting Opus 529 overloaded during overnight autonomous research (5 incidents in ~7 hours)

SUBSCRIPTION: Claude Max 20x ($200/mo)
PLATFORM: Claude Code CLI on Windows 11
SESSION DATE: 2026-04-21 (overnight EDT)

ISSUE:
Running an overnight autonomous research campaign (background Agent dispatches via the Agent tool) produced 5 distinct 529 overloaded_error responses on Opus calls between approximately 04:00 and 07:00 EDT. Each failed dispatch wasted budget and required orchestrator-level retry logic. Sonnet retries on the same prompts succeeded immediately, suggesting the issue is Opus pool-specific, not general API capacity.

REQUEST IDS (all 529 overloaded_error):
- req_011CaGZj8rFwKw4BvXyb3MLw  (~04:00 EDT, Topic 08 dispatch, Opus)
- req_011CaGbNe8nS8ny4SmgJKV64  (~04:30 EDT, Topic 10 dispatch, Opus)
- req_011CaGby8kvWtYriaj1H96TL  (~04:45 EDT, Topic 10 retry, Opus)
- req_011CaGdqs1vJF4xyJSzrRDf4  (~05:15 EDT, Topic 12 dispatch, Opus)
- req_011CaGo7kMpMnD8a1ynGrz39  (~07:00 EDT, end-session edit, Opus)

PATTERN:
All 5 failures were Opus calls. Every Sonnet retry on the same prompt succeeded within ~5 minutes. No 529s on Sonnet calls during the entire session.

EXPECTED BEHAVIOR:
Max 20x is marketed as 20x the usage of Pro tier. As a paying Max 20x customer running long autonomous workloads, I expect the subscription to actually deliver the Opus access it advertises. The point of paying $200/mo is that I can rely on the service for production-style workflows, not that I get to queue requests that fail.

ACTUAL BEHAVIOR:
Opus capacity appears undersupplied relative to what's being sold. Subscription tier provides no apparent priority on the Opus pool. Result: paying Max 20x customer's autonomous workflow stalls and requires application-level retry/fallback logic to complete the work I'm already paying you to be able to do.

ASK:
1. Provision Opus capacity to match what Max 20x marketing claims, OR
2. Document explicitly that Opus is best-effort and Max 20x ≠ priority Opus access — so customers can plan around it from the start instead of discovering it mid-session.

OBSERVED MITIGATION (in case useful for support or for the docs team):
Downgrading subagent dispatches from Opus to Sonnet eliminated all 529s for the rest of the session. This is the workaround I'd recommend Anthropic surface in the Claude Code docs for autonomous-loop users — it would have saved me ~30 min of failed-dispatch debugging tonight if I'd known up front that Opus is capacity-constrained for autonomous workflows even on Max 20x.

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Why two asks not three: dropped the "add a paid tier above Max 20x" suggestion. You already pay $200/mo. The fix is for Anthropic to deliver what's already being sold, not to invent another tier above Max 20x that you'd have to pay even more to get reliable Opus access.

Environment Info

• Platform: win32
• Terminal: windows-terminal
• Version: 2.1.116
• Feedback ID: 75649dad-9771-4488-8f32-112461f1d47c

Errors

[{"error":"Error: ENOENT: no such file or directory, unlink 'C:\\Users\\bip\\AppData\\Local\\Temp\\claude\\C--Users-bip-ClaudeProjects\\dbfda630-1941-47d1-8b34-0cfcd4bdf74f\\tasks\\aa9850e79def90a90.output'\n    at async <anonymous> (B:/~BUN/root/src/entrypoints/cli.js:7979:299)","timestamp":"2026-04-21T00:30:25.173Z"},{"error":"Error: ENOENT: no such file or directory, unlink 'C:\\Users\\bip\\AppData\\Local\\Temp\\claude\\C--Users-bip-ClaudeProjects\\dbfda630-1941-47d1-8b34-0cfcd4bdf74f\\tasks\\a2b335f0ae2b3dbdf.output'\n    at async <anonymous> (B:/~BUN/root/src/entrypoints/cli.js:7979:299)","timestamp":"2026-04-21T00:30:53.028Z"},{"error":"Error: ENOENT: no such file or directory, unlink 'C:\\Users\\bip\\AppData\\Local\\Temp\\claude\\C--Users-bip-ClaudeProjects\\dbfda630-1941-47d1-8b34-0cfcd4bdf74f\\tasks\\a8cf0ac177559cfc6.output'\n    at async <anonymous> (B:/~BUN/root/src/entrypoints/cli.js:7979:299)","timestamp":"2026-04-21T00:31:26.444Z"},{"error":"Error: ENOENT: no such file or directory, unlink 'C:\\Users\\bip\\AppData\\Local\\Temp\\claude\\C--Users-bip-ClaudeProjects\\dbfda630-1941-47d1-8b34-0cfcd4bdf74f\\tasks\\a410fa7a40fc6da7b.output'\n    at async <anonymous> (B:/~BUN/root/src/entrypoints/cli.js:7979:299)","timestamp":"2026-04-21T04:52:20.606Z"},{"error":"Error: ENOENT: no such file or directory, unlink 'C:\\Users\\bip\\AppData\\Local\\Temp\\claude\\C--Users-bip-ClaudeProjects\\dbfda630-1941-47d1-8b34-0cfcd4bdf74f\\tasks\\a2343bd9c14f191e8.output'\n   …

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