Multi-model error spike resolved in 17 min — stateless architecture proving stable under incident
Elevated errors on Claude Fable 5.1, Sonnet 5.5, and Haiku 5.5 — cause identified and resolved
Original: Elevated errors for Claude Fable 5.1, Sonnet 5.5, and Haiku 5.5
Importance: 複数モデルの同時エラー増加は本番系に即影響を与えるが、復旧が迅速だったため深刻度は中程度
Summary
Anthropic reported elevated error rates on Claude Fable 5.1, Sonnet 5.5, Haiku 5.5, and fast mode requests to Opus 5.5 on October 23. The root cause was identified and a fix was deployed; success rates returned to normal approximately 20 minutes after the initial report. The incident lasted less than an hour and affected multiple models concurrently. Monitoring continues to ensure stability.
Key Points
- Error rate spike affecting Fable, Sonnet, Haiku 5.5 and Opus 5.5 fast mode
- Root cause identified 2 min after detection; full recovery in ~17 min
- All models restored to normal; ongoing monitoring active
View developer notes (APIs, breaking changes, migration)
Multiple Claude model versions (Fable 5.1, Sonnet 5.5, Haiku 5.5, and Opus 5.5 fast mode) experienced elevated error rates on API requests. Detection at 23:37 UTC, root cause identified at 23:39 UTC, recovery confirmed at 23:54 UTC (~17 min incident window). Tracked at https://status.claude.com/incidents/h101vcmhnfky. No specific error rate percentage, token impact metrics, or retry behavior details published. Production operators should review timeout thresholds and circuit breaker configurations.
Source: https://status.claude.com/incidents/h101vcmhnfky
Outlet: Anthropic Status
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