Claude Fable 5 now available on AI Gateway (opens in new tab)

**Published:** June 9, 2026 | **Authors:** Walter Korman, Kevin Dawkins, Rohan Taneja, Jerilyn Zheng --- Claude Fable 5 from Anthropic is now available on AI Gateway. A Mythos-class model, Fable 5 is a notable step up over prior Claude models on long-running, ambiguous, multi-step tasks, executing end-to-end on work that previously required frequent human check-ins. The model sustains productive output across multi-day runs and dependably dispatches parallel sub-agents, and lower effort se...