Claude API Deprecation: What Developers Need to Know Before June 15

With three days until Anthropic retires Claude Sonnet 4 and Opus 4 API snapshots, developers should treat this as a production incident prevention exercise.

No Grace Period

Anthropic’s documentation is explicit: after June 15, 2026, API calls to claude-sonnet-4-20250514 and claude-opus-4-20250514 return errors. There is no gradual wind-down or fallback routing.

Where Model IDs Hide

Common locations for hardcoded model strings:

  • Python/TypeScript SDK initialization (model="claude-sonnet-4-20250514")
  • Environment variables (ANTHROPIC_MODEL, CLAUDE_MODEL)
  • Docker Compose and Kubernetes ConfigMaps
  • GitHub Actions workflow YAML
  • Terraform/IaC templates provisioning AI endpoints
  • Third-party observability dashboards filtering by model ID
DeprecatedActive Replacement
claude-sonnet-4-20250514claude-sonnet-4-6
claude-opus-4-20250514claude-opus-4-8
claude-opus-4-1-20250805claude-opus-4-8 (by Aug 5)

Opus 4.7+ Sampling Change

Remove temperature, top_p, and top_k from Opus 4.7+ requests. The API returns HTTP 400 if these are set. Use system prompts and few-shot examples for behavioral control instead.

Verification Steps

  1. grep -r "claude-sonnet-4-20250514\|claude-opus-4-20250514" .
  2. Run integration tests against replacement models
  3. Check Claude Console Usage export for unexpected model strings
  4. Update documentation and runbooks before June 15