Claude API Model Retirement June 15: Migration Checklist for Enterprise Developers

Anthropic will retire two Claude API model snapshots on June 15, 2026 with no grace period. Production integrations using hardcoded model IDs will fail immediately after the cutoff.

Models Retiring June 15

Retiring ModelReplacement
claude-sonnet-4-20250514claude-sonnet-4-6
claude-opus-4-20250514claude-opus-4-8

Convenience aliases claude-opus-4-0 and claude-sonnet-4-0 also resolve to retiring snapshots and will fail.

Migration Checklist

  1. Export API usage from Claude Console to identify affected workloads
  2. Audit hardcoded model strings in application code, environment variables, CI/CD pipelines, Docker images, and Kubernetes manifests
  3. Update Agent SDK configurations and third-party tools embedding Claude model IDs
  4. Test replacement models in staging before June 15
  5. Monitor error rates on retirement day — requests to retired models return errors with no gradual wind-down

Opus 4.7+ Parameter Restriction

Claude Opus 4.7 and later (including Opus 4.8) return 400 errors when temperature, top_p, or top_k are set to non-default values. Developers must omit these parameters and use prompting instead.

Additional Retirement

claude-opus-4-1-20250805 retires August 5, 2026 — replacement: claude-opus-4-8.

Anthropic notified affected customers by email on April 14, 2026 (Sonnet/Opus 4) and June 5, 2026 (Opus 4.1).