Yes, licensed separately: Protégé API, content search, CourtLink, Lex Machina. What each returns, what Shepard's lacks, and the honest path for a small firm.
[ KEY TAKEAWAYS ]
Yes, LexisNexis has an API. It sells a Lexis APIs portfolio separately from Lexis+ seats: a new Protégé API, REST APIs for searching and retrieving legal and news content, and CourtLink, Lex Machina, State Net and Law360 APIs, all behind OAuth 2.0, role-based access, firm-wide throttling and audit logging. You get it by talking to an API specialist, and pricing depends on the products and the volume you need. The Protégé Legal Data API is positioned at firms of roughly 100 lawyers or more. Shepard's treatment signals aren't documented as an API. And Claude's legal plugins run inside Lexis+ with Protégé, which is the reverse of a Lexis connector inside Claude. So a small firm that wants Claude talking to Lexis has three honest shapes to choose from, and the first question is what your agreement includes.
APIs named on the Lexis APIs page today: Protégé, REST, CourtLink, Lex Machina, State Net, Law360, Cognitive.
announced as coming soon: a Content API and an MLex API.
lawyers, where Legal Technology Hub positions the Protégé Legal Data API.
Shepard's APIs documented publicly. Ask before you design around one.
We got this wrong ourselves a day before writing it. A four-attorney firm in Oklahoma sent us a scope of work that asked for research questions answered in Claude, grounded in LexisNexis, with Shepard's signals, and citation checking of drafts. Our first read, from the press coverage, was that Lexis had no API at all. It does. What it doesn't have is an API that comes with a Lexis+ seat, a public price, or a documented Shepard's endpoint. The difference between those two statements is the difference between promising a build and pricing a feasibility week, so here is the whole picture, with the sources.
LexisNexis describes its APIs as "a flexible gateway to LexisNexis legal content, business intelligence, analytics, and AI capabilities" and groups them into REST APIs, Cognitive APIs and the new Protégé API. The product page lists these, with the Protégé API marked as new.
| API | What it returns | Who it is for | Access |
|---|---|---|---|
| Protégé API | Conversational search and insights grounded in Lexis content and, where connected, the firm's own documents; "detects when user queries warrant LexisNexis content or firm knowledge" | Corporate legal and firms of about 100 lawyers or more, per the Legal Technology Hub listing | Licensed separately |
| REST APIs | Search and retrieve legal and news content, set up alerts for new content | Any organization that pipes Lexis content into its own tools | Licensed separately |
| CourtLink API | Federal and state court filings, docket updates, case tracking, litigation activity | Litigation monitoring across matters and jurisdictions | Licensed separately |
| Lex Machina API | Litigation analytics: judges, attorneys, parties, resolutions, damages, timing | Strategy and business development teams | Licensed separately |
| State Net API | Legislation, regulations, agency documents, ordinances, executive orders, ballot measures | Regulatory and government affairs | Licensed separately |
| Law360 API | Law360 core coverage across 65 or more sections | Knowledge management, current awareness | Licensed separately |
| Cognitive APIs | Entity recognition, data enrichment, normalization | Data teams building on Lexis content | Licensed separately |
| Content API, MLex API | Announced as coming soon | Not yet |
Source: lexisnexis.com Lexis APIs page and the Legal Technology Hub listing, read 7 October 2026. Security on every API: OAuth 2.0, role-based access, firm-wide throttling, audit logging.
Nowhere on that page. Shepard's citation validation is a feature of Lexis+ with Protégé and of Lexis for Microsoft Office, and LexisNexis has been building more of it into Protégé's workflows through 2026. Whether any API entitlement returns treatment signals (followed, distinguished, overruled, questioned) is not documented. If your citation-checking plan depends on it, get that answer from the account team in writing before anyone writes code.
No. The seat and the API are two different purchases. LexisNexis's own FAQ answers "how do I get access" with a conversation: an API specialist reaches out to schedule a free trial activation, and there is a developer portal behind that. On price it says only that "API access and pricing depend on the specific products and data volumes your organization needs." We've seen no public rate card, and the Protégé Legal Data API's positioning at firms of roughly 100 lawyers tells you where LexisNexis expects that conversation to happen.
For a firm of four to twenty attorneys this means a second line on the budget that nobody can estimate from the outside. It also means the honest first step is a written question to your account team, which is why we price it as a feasibility week rather than a build.
"To obtain access to the Lexis API, please contact an API specialist." Lexis's own page, which is also the honest summary of what the licence is: a conversation, priced by product and volume.
Three shapes, in order of how much they depend on LexisNexis.
Your firm licenses a Lexis API
A custom connector in your own cloud, with each user signing in under their own Lexis entitlement, lets Claude search and retrieve Lexis content through the REST or Protégé API. Audit stays with you. The connector only does what the licence allows, so Shepard's is in or out depending on the entitlement, not on the code.
You have Lexis+ with Protégé and no API
Claude's legal plugins run inside Protégé since 24 February 2026, grounded in the Lexis repository. Research happens there. Claude plus your practice system handle the memo, the matter record and the filing. Nothing is piped between the two; a person carries the authorities across.
You have Lexis+ only, or want citation checking without any API
Claude extracts every case and statute citation from a draft, lists the proposition each one supports, and produces a Shepardize list. The attorney runs Shepard's in Lexis for Microsoft Office or Lexis+. A public court-opinion database such as CourtListener gives a second, free existence check. Slower than an API, honest about who verified what.
A fourth shape is on LexisNexis's side of the table. On 27 May 2026 its Chief Technology Officer, Greg Dickason, published what the company learned from evaluating MCP-based workflows: side-by-side tests of large language models alone, the same models with a LexisNexis MCP connector, and Lexis+ with Protégé. The bar it set for moving forward is the useful part for any firm. The criteria are not met if a model with the connector "introduces additional legal interpretations, adjacent statutes, or citations not provided by LexisNexis," or if the output could lead a user to believe the full response was grounded in LexisNexis authority when parts were generated by the model. So a Lexis connector inside Claude is being tested, has not shipped broadly, and will come with attribution rules when it does. Plan for the three shapes above and treat the fourth as upside.
Do not plan the build before the answer A four-attorney firm asked for research grounded in Lexis with Shepard's signals. Until the account team confirms the entitlement and the API scope, the only honest quote is a feasibility week with three outcomes. A build price before that is a guess dressed as a number.
The scope document that prompted this post asked for research questions answered in Claude with supporting authorities and links back to the firm's Lexis account, Shepard's treatment signals with links to full reports, and a draft-review workflow that extracts citations from memoranda and flags adverse treatment, overruled authorities, nonexistent citations and anything that could not be verified. It also, to its credit, asked the vendor to "validate access to the appropriate LexisNexis / Protégé APIs with the firm's account team before committing to connector functionality."
What we did not do
Quote the Lexis build
No entitlement in hand, no documented Shepard's endpoint, no public price. A fixed price for that is a guess dressed as a proposal, and the firm would have found out in week four.
What we did instead
A feasibility week with three outcomes
One written session with their account team and a Lexis API specialist. Outcome one: an entitlement at a price that fits, so a fixed-price connector build follows. Outcome two: no entitlement, so the citation-extraction workflow ships as a firm skill with the attorney closing the loop in Lexis. Outcome three: an entitlement that exists but costs more than the workflow is worth, which is a decision for the partners, in writing, with the numbers on the table.
Their research will run in Protégé either way. What changes between the outcomes is whether Claude can pull authorities into the memo on its own, or whether a person carries them across. Both are workable for a four-attorney firm. Only one of them should be promised before the account team answers.
Writing a scope that mentions LexisNexis?
We read your Lexis agreement, your practice system and your Claude plan together on a 30-minute call and tell you which of the three shapes you can actually build, before anyone quotes you.
Six questions, in writing
Bring the answers to the scoping call. They decide the build in about ten minutes.
One more thing worth knowing while you ask. Lexis+ with Protégé already connects to Microsoft 365 Copilot and to iManage, NetDocuments and SharePoint, and names OpenAI and Anthropic as model partners on its integrations page. Thomson Reuters takes the same posture with CoCounsel and Westlaw, and Clio bought vLex to bring research inside its own platform. The research vendors are pulling the assistants inside their walls, not the other way round. A small firm's plan should assume that direction for the next year and keep the connector in its own cloud for everything that is not research.
Yes. LexisNexis sells a Lexis APIs portfolio separately from Lexis+ seats: a new Protégé API, REST APIs for searching and retrieving legal and news content and setting alerts, the CourtLink API for dockets, the Lex Machina API for litigation analytics, the State Net API for legislation and regulation, and the Law360 API, with Content and MLex APIs announced as coming soon. All of them sit behind OAuth 2.0, role-based access, firm-wide throttling and audit logging.
No. LexisNexis says API access and pricing depend on the specific products and data volumes your organization needs, and the path to access is a conversation with an API specialist who activates a trial. A Lexis+ or Lexis+ with Protégé seat does not include API access by itself.
Only in one of three shapes. If your firm licenses a Lexis API, a custom connector in your own cloud can let Claude search and retrieve Lexis content under your entitlement. Without an API, Claude's legal plugins already run inside Lexis+ with Protégé, so research happens there and the memo and matter record live in Claude and your practice system. The third shape is a citation-extraction workflow in Claude with the attorney running Shepard's in Lexis. No LexisNexis connector is listed in Claude's directory as of 7 October 2026.
LexisNexis lists a new Protégé API on its API page, and Legal Technology Hub lists a Protégé Legal Data API that embeds conversational search and insights into intranets, client portals, practice tools and bespoke applications, positioned at corporate legal departments and firms of roughly 100 lawyers or more. Whether a smaller firm can license it, and at what price, is a question for the API specialist.
Not one that LexisNexis documents publicly as of 7 October 2026. Shepard's treatment signals are part of Lexis+ with Protégé and Lexis for Microsoft Office. Whether an API entitlement returns treatment signals is something to confirm in writing with your account team before you design a citation-checking workflow around it.
LexisNexis does not publish API prices. Its own FAQ says access and pricing depend on the products and data volumes involved. Ask the API specialist for a written quote for your seat count and expected query volume, and ask whether Shepard's data is part of it, before you commit to any build.
NEWSLETTER
[ WRITTEN BY ]
Petar Jovanović
Co-Founder & Technical Lead
Co-Founder and Technical Lead at Oktopeak. Builds regulated software for legal and healthcare teams, and leads the rescues of codebases other vendors left half-finished.
[ LEGAL TECH ]
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