Lex V2: Knowledge Bases & Style Guides
Hey! Nathan here, founder of Lex (https://lex.page), the modern writing platform with AI editing tools built in.
Over the last several weeks, we've rolled out a series of five major releases that significantly improved Lex. So much so, that we've come to think of them as collectively forming Lex V2.
Today, the last of those five releases: Style Guides & Knowledge Bases
LEX V2 — part 5 of 5 🎉
— Nathan Baschez (@nbashaw) May 22, 2025
Introducing two new ways to make AI a better writing partner:
1. Style guides, to get edits that sound like you
2. Knowledge bases, to teach AI what it needs to know https://t.co/TNGyfoL1CO pic.twitter.com/Fe7gt8z4WZ
What we’re solving
We’ve found that there are two main reasons for AI edits to miss the mark:
They sound nothing like you
They’re disconnected from the context around your writing
So we built two easy to set up tools to solve these problems.
Pro Tip: These features leverage recent breakthroughs in AI's ability to understand complex context. While available to all users, you'll get significantly better results with Lex Pro's premium models (GPT-4.1, Claude 4, Gemini 2.5).
Click here for a 7-day free trial!
Style Guides
Drop in writing samples and Lex learns to match your voice. Whether you're writing newsletters, technical docs, or novels, you'll get suggestions that actually sound like you—not generic AI text.
Check out this guide to learn more →
Knowledge Bases
Share research, docs, videos, or any other background material with Lex. Instead of generalized advice, you get an AI assistant that understands your work inside and out.
Check out this guide to learn more →
Lex V2 Town Hall
Following our V2 releases, we're planning to spend some time polishing what we've built and gathering feedback from writers about what works, what needs more attention, and what we should focus on next.
Claude 4 in Lex Pro!
Anthropic just released Claude Opus 4 and Claude Sonnet 4, and we'll be adding both to Lex Pro by end of day.
While it's early, initial testing is promising: Opus 4 impresses with sustained, complex tasks and deeper reasoning, while Sonnet 4 brings significant improvements to instruction-following and clear communication.
Claude 3.5 Sonnet was our preferred LLM for writing for months (until dethroned by GPT-4.1). We’re excited to see how the Claude 4 models compare.
What happened to Context Tags?
You may remember Context Tags, which were a similar feature. We've switched to Knowledge Bases and Style Guides for two key reasons:
Clearer terms: "Context Tags" was a new term users had to learn. Style Guides and Knowledge Bases are intuitive at a glance.
Better results: With Context Tags, the AI had to guess how to use the information. Style Guides and Knowledge Bases give clear direction—use this for style, that for facts.
Don’t worry if you’re a heavy context tag user! We’ve migrated your tags into Style Guides or Knowledge Bases (depending on each tag).
That's release 5/5 of Lex V2 — but we’re far from done! More coming soon 👀
As always, we love hearing from you. Hit reply with any questions or feedback!
—Nathan