Anthropic releases Claude Fable 5

Category: AI
Status: confirmed
Sources: Anthropic announcement, models overview, TechCrunch, HN discussion 2,562 points
Summary: Claude Fable 5 (claude-fable-5) became generally available on 2026-06-09 across the Claude API, Amazon Bedrock, Vertex AI, and Microsoft Foundry. Context window is 1M tokens, max output is 128K tokens, adaptive thinking is always on, and pricing is $10/$50 per MTok input/output. Claude Mythos 5 (claude-mythos-5) is available in limited access to approved customers through Project Glasswing at the same context and pricing. Claude Sonnet 4 and Claude Opus 4 retire on 2026-06-15; Claude Opus 4.1 retires on 2026-08-05.
Why it matters: Developers using claude-sonnet-4-20250514 or claude-opus-4-20250514 must migrate before 2026-06-15 or requests will fail.
Follow-up: Check 2026-06-15 for Claude Sonnet 4 and Opus 4 retirement impact on production workloads.