Anthropic narrows incident to Opus and Sonnet 4.6, shifts from investigating to identified with major impact
Published Mar 21, 2026, 12:41 AM UTC
Key entities
TLDR
Treat Claude Opus and Sonnet 4.6 as under a major identified incident; keep automatic failover, conservative rate limits, and clear user messaging until Statuspage marks containment or resolved with root cause and recovery details.
Why this matters
Broadened impact to Sonnet 4.6 plus continued major severity implies risk across both API and web app experiences where these variants are selectable (medium confidence), combining scope notes in the identified update with the earlier Opus 4.6 investigation.
What changed
- Scope: Incident expanded from Opus 4.6 alone to both Opus and Sonnet 4.6, per Anthropic’s Statuspage.
- Status: Moved from “Investigating” to “Identified,” signaling Anthropic has isolated the issue but not resolved it yet.
- Severity: Remains “Major,” with elevated error rates persisting across affected variants.
Topic context
Use this page when you want fast context on confirmed model launches from OpenAI, Anthropic, Google DeepMind, xAI, Meta, and similar labs without scanning every release note, model card, or developer post yourself. Key angles: openai, anthropic, google deepmind, gemini.
Summary
Anthropic updated its status from investigating elevated errors on Claude Opus 4.6 to identifying a major issue that also affects Sonnet 4.6, indicating broader model variant impact but progress in diagnosis; integrators should sustain failover and throttling until an official containment or resolved update with root cause is posted.