HighDeprecation
Claude Sonnet 4.5/4 long-context beta retired — migrate to Sonnet 4.6 or Opus 4.6
Action Required
Applications relying on long-context prompts will return errors for requests exceeding 200k tokens unless migrated to Claude Sonnet 4.6 or Claude Opus 4.6.
AI Impact Summary
The 1M-token context window beta for Claude Sonnet 4.5 and Claude Sonnet 4 has been retired, restricting context length to the standard 200k tokens. Any workflow that previously sent documents or prompts exceeding 200k tokens will fail unless migrated. To regain long-context capabilities, migrate to Claude Sonnet 4.6 or Claude Opus 4.6 and update client integrations to target the new model family, with testing focused on tokenization, prompt assembly, and compatibility across endpoints.
Claude Sonnet 4.5/4 long-context beta retired — migrate to Sonnet 4.6 or Opus 4.6
Affected Systems
Claude Sonnet 4.5
- Date
- Date not specified
- Change type
- deprecation
- Severity
- high