Claude Platform release notes — July 15, 2026
Mid-conversation system messages are available on Claude Fable 5, Claude Mythos 5, and Claude Opus 4.8, on the Claude API, Claude in Amazon Bedrock , and Google Cloud . No beta header is required. Thi…
Added
- Mid-conversation system messages are now available on Claude Fable 5, Claude Mythos 5, and Claude Opus 4.8 via the Claude API, Claude in Amazon Bedrock, and Google Cloud