Anthropic · model retirement
Claude Sonnet 4 and Opus 4 API model IDs were retired.
Anthropic’s release notes say requests to these IDs now return errors. The reviewed AI Provider Watch record preserves the source, timing, affected surface, and suggested migration review.
- Change date
- Jun 15, 2026
- APW observed
- Jun 17, 02:17 UTC
- Source authority
- Official docs