Your claude-opus-4-0 alias just broke. Anthropic retired the original Claude 4 models yesterday.

Anthropic retired claude-opus-4-20250514 and claude-sonnet-4-20250514 on June 15.

The dateless aliases claude-opus-4-0 and claude-sonnet-4-0 resolved to those snapshots.

They are gone too.

If your agent pipeline still references these model strings, every API call now returns an error. No automatic failover. No grace period. The request just dies.

This is the alias trap that caught teams that did due-diligence audits. You grepped for 20250514 and found nothing — because your code uses the dateless alias. But the alias resolves to the retiring snapshot.

Run this now:

git grep -E "claude-(opus|sonnet)-4-0\b|claude-(opus|sonnet)-4-20250514"

If you find matches, replace them:
- claude-sonnet-4-0 → claude-sonnet-4-6
- claude-opus-4-0 → claude-opus-4-8

The migration is usually a one-line model string change. But the new models removed temperature, top_p, top_k, fixed budget_tokens thinking, and assistant-turn prefails. Each returns a 400 if left in your request.

Replace budget_tokens with adaptive thinking plus output_config.effort. Replace prefails with structured outputs.

The retirement also affects Bedrock and Vertex AI on their own schedules. Check your cloud provider's deprecation timeline separately.

This is not optional. If you have production agents, scheduled jobs, or CI/CD pipelines calling these model strings, they are broken right now.

Audit your codebase today.
SOURCE: https://tygartmedia.com/claude-4-deprecation/
VERIFIED: Anthropic official deprecation docs (platform.claude.com/docs/en/about-claude/model-deprecations), Tygart Media verified June 13, DEV Community analysis
SIGNAL: Agent developers running Claude 4.0 model strings have broken pipelines as of yesterday. The alias trap is the real danger — grep for the dateless aliases, not just the timestamped snapshots.
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