Claude Fable 5.1 improves on Claude Fable 5 across the board, with the biggest gains in agentic coding, long-running agentic workflows, and knowledge work: long code refactors, front-end and visual code generation, and finance and analysis tasks in particular. It also tends to be more concise than Fable 5 in its plans and summaries. We recommend testing it as a direct upgrade wherever you use Fable 5 today, and alongside Opus 5 on reasoning-heavy tasks.
Success rate of requests sent by the Amux AI gateway to each provider. Client errors are excluded.
Tok/s
24 hours · 10/14–10/22
Average output speed of streaming requests, in tokens per second (TPS).
TTFT
24 hours · 10/14–10/22
Average time to first token (TTFT) of streaming requests, measured from request dispatch to the first token received.
Activity
24 hours · 10/14–10/22
Relative request activity over time, broken down by serving provider. Indexed to the peak within the selected range (= 100); reflects trends and provider share, not absolute volume.
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