Claude Opus 4 changelog

Every change to Claude Opus 4 that Modelpeers has recorded, newest first, each with the source it came from. The record starts Apr 14, 2026.

June 2026

2 models from Anthropic

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.

2 models from Anthropic

Anthropic announced that claude-sonnet-4-20250514 and claude-opus-4-20250514 would retire on the Claude API on June 15, 2026.

Who is affected:: Apps calling claude-sonnet-4-20250514 or claude-opus-4-20250514.
Action needed:: Migrate to Claude Sonnet 4.6 and Claude Opus 4.8.

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