Lexis+ AI

Overview

Lexis+ AI is LexisNexis's generative-AI legal assistant for conversational legal research, summarization, drafting, and document analysis, grounded in the LexisNexis corpus of primary law and secondary sources with linked, Shepard's-validated citations. It reached US general availability in October 2023 and later expanded into the UK, Canada, France, and Australia. In February 2026 LexisNexis launched Lexis+ with Protege, a second-generation, end-to-end workflow platform that replaces the first-generation Lexis+ AI experience.

What it does

It answers legal questions conversationally over authoritative LexisNexis content and web sources, summarizes uploaded documents and search results, and drafts and refines transactional agreements, contracts, litigation motions, briefs, complaints, and client communications, including inside Microsoft 365. The Protege assistant adds insights on judges, courts, and counsel, SEC-filing and patent analysis, and Vault for uploading and analyzing sensitive documents. Lexis+ with Protege adds pre-built and no-code custom multi-step workflows; users approve the plan before AI agents carry out the work, and LexisNexis describes fully autonomous multi-step execution as an emerging capability. Because lawyer review is central, it operates as a copilot to supervised agent rather than an autonomous one.

Integrations & setup

Works inside Microsoft 365 (Word, Outlook, PowerPoint) and integrates with document and content systems including iManage, SharePoint, OpenText, and Google Drive. It is delivered as SaaS within a secure LexisNexis environment; LexisNexis states it never uses customer data to train AI models and does no cross-user data training.

Pricing

Enterprise, quote-based pricing with no fully public rates. Third-party sources report Lexis+ AI tiers and per-user costs in the low hundreds of dollars per month, with Lexis+ with Protege custom-priced and the most useful features reportedly costing significantly more (reported, not official). Contact LexisNexis sales for a quote.

Models

LexisNexis describes a legal-optimized configuration that blends multiple LLMs from leading providers grounded in LexisNexis sources with Shepard's citations, plus a general-AI configuration with access to models from OpenAI, Anthropic, and Google for broader reasoning. The exact current model mix is not fully published.

Best for / not for

Best for law firms (small to large), corporate legal departments, government, and academia that want generative legal AI grounded in authoritative primary law with citation validation and Microsoft 365 integration. Less suited to buyers needing transparent self-serve pricing or fully autonomous end-to-end automation.

Alternatives

Harvey is a purpose-built legal AI platform with supervised legal workflows (and uses LexisNexis primary-law content). Spellbook focuses on contract drafting and review inside Word. Luminance and Robin AI focus on contract analysis and review.