Anthropic: v12.28.0

12.28.0 (2026-06-09)

Full Changelog: Anthropic-v12.27.0...Anthropic-v12.28.0

Features

• api: add support for claude-mythos-5 and claude-fable-5, with support for server-side fallbacks on refusal (a9d68ed)
• client: adds client-side fallbacks middleware for API providers that do not support server-side fallbacks (a9d68ed)

Bug Fixes

• credentials: accept access_token-type credentials files (#23) (4a5b809)