Anthropic dropped model selection guidance and Fable 5, Mythos 5 availability text.

Builders lose page-backed references for model choice, access paths, launch timing, and provider availability from this page.

The removed section described Fable 5 as generally available and Mythos 5 as limited availability through Project Glasswing.

• Aug 20, 2026Anthropic made the Files API generally available on the Claude API without the beta header.
• Aug 20, 2026Agent Skills and the Skills API are generally available on the Claude API.
• Aug 20, 2026Claude Managed Agents in self-hosted sandboxes can now attach memory stores.

This is the world we build in. It moves this fast. We move with it.