Claude Sonnet 4 and Claude Opus 4 retired

Requests to claude-sonnet-4-20250514 and claude-opus-4-20250514 on the Claude API now return an error.

Who is affected:: Apps still calling Claude Sonnet 4 or Opus 4 on the Claude API.
Action needed:: Switch to Claude Sonnet 4.6 or newer and Claude Opus 4.8 or newer.

Source

"All requests to these models on the Claude API will now return an error."

Claude Platform release notes (API)

Published Jun 15, 2026

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