Fable 5.1 was released on Sep 1, 2026. It scored 52.6% on an agentic science benchmark. Three months ago, Fable 5 scored 24.7%.
That is a real leap in agentic capability. And most law firms still will not be able to run a single privileged document through it.
To test it, I built a 3D replica of the human brain, running entirely in the browser. It followed through on a genuinely complicated task and the output holds up.
Open Cortex Atlas →Two things worth knowing:
It fixes its own work. In my short test it caught and cleared its own bugs before handing anything back. Other testers are reporting the same.
It is still an expensive model. Price is unchanged at $10 in and $50 out per million tokens. Cache pricing improved, so typical work and long agentic runs may come out cheaper than before. But this is a model you point at your hardest problems, not your default.
Now the part that matters most if you work with sensitive information.
Fable 5.1 is still a Covered Model. That means no zero data retention (ZDR) and a 30 day retention requirement. For a lot of work inside a law firm, that alone rules it out.
Anthropic did announce Enterprise Frontier Safeguards to close the gap, with data held in infrastructure the customer controls. That is coming later. As of today, the position is unchanged.
So I am watching what else ships over the next couple of months.