HighDeprecation
Claude Sonnet 4.5/4 — 1M token context beta retired, migrate to 4.6 or Opus 4.6
Action Required
Applications using Claude Sonnet 4.5 or 4 with context windows above 200k tokens will experience immediate API failures until migrated to Sonnet 4.6 or Opus 4.6.
AI Impact Summary
Anthropic is discontinuing the 1M token context window beta (context-1m-2025-08-07) for Claude Sonnet 4.5 and 4.0, effective immediately. Any request exceeding 200k tokens to these models will now fail. Claude Sonnet 4.6 and Claude Opus 4.6 are the only supported paths forward for applications requiring extended context, requiring code changes to model selection and potentially API header updates.
Claude Sonnet 4.5/4 — 1M token context beta retired, migrate to 4.6 or Opus 4.6
Affected Systems
Claude Sonnet 4.5
- Date
- Date not specified
- Change type
- deprecation
- Severity
- high