Release Notes
Fable 5.1 Model Access
Fable 5.1 is now available as a model provider in Harvey, giving workspaces that opt in access through the model selector.
What’s New
Fable 5.1 is now available in Harvey. Built by Anthropic, Fable 5.1 is designed to support complex, document-heavy analysis, with particular strength in litigation and dispute resolution, as well as strong performance on data privacy, cybersecurity, and capital markets work.
Fable 5.1 also delivers thorough results at lower reasoning settings, using roughly half the output tokens at its lowest setting while remaining thorough, a useful efficiency gain for high-volume work such as reviewing agreements.
Select Fable 5.1 when working on tasks that benefit from Anthropic's latest model capabilities. Learn more in our blog post for Fable 5.1.
Important: Fable 5.1 falls under Covered AI Services and requires a signed contract addendum. Contact your Customer Success Manager or account team to enable Fable 5.1 in your workspace or to confirm your workspace’s eligibility for ZDR.
Why It Matters
Fable 5.1 gives teams a more capable model option for complex, document-heavy legal work, with particular strength in litigation and dispute resolution. Its ability to produce thorough results at lower reasoning levels can help teams manage high-volume work more efficiently without sacrificing quality. Because Harvey remains multi-model by design, you can route a task to Fable 5.1, or to any other model, based on what best fits the work at hand.
How To Use
You can find detailed information on how to request, enable, and use Fable 5.1 in your workspace in our article: Use Fable 5 and Fable 5.1 in Harvey.
Workspaces that have already opted in to Fable 5 will get Fable 5.1 access automatically.
FAQs
Q: Is Fable 5.1 used automatically?
No, Fable 5.1 is not part of Auto mode. It only runs when you explicitly select it in the model selector.
Q: Is Fable 5.1 automatically included in my contract?
No. Fable 5.1 is subject to our Covered AI Services, and usage is billed separately. Contact your account team for more details.
Q: If I already opted in to Fable 5, do I need to opt in separately for Fable 5.1?
No. If you've opted in to Fable 5, you'll get Fable 5.1 access in Harvey automatically.