May 13, 2026 | CoCounsel

In legal work, the stakes are simply too high for approximation. Legal professionals are accountable for their outputs; errors carry real consequences, and being almost right is not good enough.  

Nowhere is that truer than in Section 101 patent eligibility, one of the most consequential and frustrating challenges in patent practice today, and the problem that brought Sterne Kessler Goldstein & Fox and Thomson Reuters together to build something new inside CoCounsel Legal. 

Why Section 101? Why Now? 

Section 101 patent eligibility is a question at the center of most utility patent disputes today. It is often a decisive factor in patent litigation, and one of the quickest ways to win or lose a case. The legal test asks whether a technical invention is the kind of subject matter the patent system protects, meaning it must be more than a general idea and must represent a concrete, technical improvement. 

 In theory, the framework is clear. In practice, it is anything but: 

• Key concepts lack precise definitions, leaving wide room for interpretation.  
• The analysis is deeply precedent-dependent, and outcomes hinge on finding the right prior cases among hundreds of fact-specific decisions. Missing a key precedent can mean the difference between a strong argument and a weak one. 

And all of this unfolds under constant pressure. Clients need answers fast; matters are often fixed-fee, and the uncertainty is genuinely difficult to explain. 

For patent owners seeking to assert a patent, understanding its vulnerability under Section 101 is essential before litigation begins. For defendants, a fast, reliable eligibility assessment can reveal a path to an early win. For both sides, the current reality often looks the same: assign a junior associate to research similar cases, spend hours or sometimes days finding the right precedents, and still wonder whether something important was missed. 

This is the kind of problem that demands a fiduciary-grade solution: one built not for the average task, but for the specific, high-stakes reality of patent practice. 

Unmatched IP Expertise, Delivered at Scale 

The Patent Claim Eligibility Analyzer was not built by technologists who then consulted practitioners. It was built with practitioners at the center of every decision — and with a caliber of technical expertise on both sides that distinction shapes everything about what the Patent Claim Eligibility Analyzer can do. 

Thomson Reuters engaged Sterne Kessler through a forward deployed engineering motion, a model that pairs engineers who combine strong legal backgrounds with deep AI and technical expertise and embeds them directly alongside practitioners. The Thomson Reuters engineering team worked side by side with Sterne Kessler’s IP litigators to deeply understand their workflows, co-build the solution in rapid iterations, and move with speed and flexibility.  

The result is a tool shaped by the kind of tight, trust-based collaboration that only happens when both sides bring genuine depth to the table. 

Sterne Kessler brings decades of litigation-tested intellectual property expertise to this partnership. The firm worked alongside Thomson Reuters’ engineers and editorial teams to translate the way experienced IP practitioners approach Section 101 — their analytical frameworks, their precedent instincts, their litigation-proven methodologies — into a repeatable, scalable workflow now inside CoCounsel Legal. 

That meant curating an initial corpus of approximately 200 highly relevant Federal Circuit Section 101 decisions, cases selected not by keyword, but by their factual and analytical relevance to the kinds of claims practitioners encounter in real matters. Thomson Reuters editorial teams then reviewed and augmented that corpus, applying the same editorial rigor that underpins Westlaw. 

The result is a workflow grounded in practitioner intelligence, trusted legal content, and engineering — combined at a depth that general-purpose AI tools simply cannot replicate. 

Built for Real IP Work

The Patent Claim Eligibility Analyzer reflects how IP work is actually done.

How the Patent Claim Eligibility Analyzer Works

1. Enter a patent claim: Select the Patent Claim Eligibility Analyzer in CoCounsel Legal and paste a claim directly into the chat.
2. CoCounsel applies the same Step 1 / Step 2 logic that courts use: The Patent Claim Eligibility Analyzer structures the analysis the way judges do, first asking whether the claim is directed to a general or abstract idea, then whether it adds a meaningful technical improvement.
3. CoCounsel finds the most relevant court decisions for that specific claim: Using semantic analysis rather than keyword search, the Patent Claim Eligibility Analyzer matches the claim to prior Section 101 cases with similar fact patterns, so practitioners surface the right cases, not just the most frequently cited ones.
4. It draws from a curated corpus built by Sterne Kessler and Thomson Reuters editors: The workflow leverages an initial set of approximately 200 highly relevant Section 101 cases, curated by Sterne Kessler and reviewed and augmented by Thomson Reuters editorial teams.
5. It explains why each cited case matters: Rather than listing citations, CoCounsel provides reasoning that connects the claim’s language to the reasoning and outcomes in those cases, giving practitioners a litigation-ready foundation, not just a list of results.
6. Citations link directly to Westlaw: Every source is verifiable. Practitioners can validate citations and continue deeper research as needed, maintaining full accountability for the final work product.

The Patent Claim Eligibility Analyzer surfaces both binding and persuasive authority when factually relevant, reflecting how Section 101 arguments are actually made in practice. The goal is not to replace attorney judgment. It is to give attorneys a faster, more consistent, more defensible foundation from which to exercise it, so less time is spent on the research phase and more time is spent on strategy, client counsel, and the work that requires human expertise. 

For patent owners, that means a stronger, faster assessment of a patent’s eligibility risk before litigation begins. For defendants, it means a rapid, precedent-backed read on Section 101 positions from the outset of a case. 

For both, it means a head start on brief writing, a more consistent work product across matters and experience levels, and greater confidence that no key precedent has been missed. 

A New Model for Legal Product Innovation 

Beyond the Patent Claim Eligibility Analyzer itself, this partnership represents something worth examining at a higher level: a fundamentally different model for how legal AI products can and should be built. 

While building useful legal technology has always required thinking like a lawyer, the traditional approach to legal technology development across the industry follows a familiar pattern. Technologists identify a problem, build a solution, and bring it to market. Practitioners are consulted but they are largely recipients of the finished product. Expertise flows in one direction. 

This partnership inverts that model. Sterne Kessler did not simply advise on the Patent Claim Eligibility Analyzer, they co-developed it, inspired by the firm’s practical methodologies for Section 101.

What began as a co-development initiative has evolved into a scalable market offering available to patent practitioners across CoCounsel Legal. In doing so, it has demonstrated what is possible when practitioners and technologists collaborate. 

That model also opens new possibilities for how law firms think about their own expertise. Firms are evolving the ways they create value from their knowledge, and this partnership is an example of what it looks like when a firm’s internal intelligence becomes a repeatable, scalable offering. 

CoCounsel Legal’s architecture is designed to enable exactly this kind of forward-deployed, domain-specific innovation, making it possible to translate specialized expertise into scalable, trusted AI experiences. The Patent Claim Eligibility Analyzer is the first proof point. 

Additional co-developed workflows are already in development, with the ambition of bringing the same practitioner-built, precedent-grounded approach to other complex areas of patent law, signaling what is possible across specialized legal domains where expertise is the differentiator and where the stakes are too high for approximation. 

The Standard the Profession Deserves 

What makes the Patent Claim Eligibility Analyzer meaningful is not just what it does. It is the standard it was built to. Every output is grounded in a curated, editorially reviewed body of case law. Every citation links to a verifiable Westlaw source. The analytical structure mirrors the reasoning courts actually apply. And the workflow is explicitly designed to support attorney judgment, not substitute for it. 

That is fiduciary-grade AI. It is not a general-purpose tool adapted for legal work, but a purpose-built solution grounded in authoritative content, shaped by the expertise of practitioners who perform this work at the highest level, and accountable to the professional standards that patent practice demands. 

The Thomson Reuters and Sterne Kessler partnership was built on that standard. And as the collaboration deepens and expands, it is the standard we will keep.