Marketing & Sales · Tip

Publishing an llms.txt File for SaaS

Add plain-text markdown documentation to help AI models index and recommend your product

This technique involves publishing an llms.txt or llms-full.txt file on your website to provide LLMs with concise, machine-readable context about your product. It functions as an AI-specific documentation layer that search engines and chatbots like ChatGPT, Claude, and Perplexity can parse directly to surface accurate recommendations. Following implementations like Vercel's, the format pairs structured metadata headers with plain markdown documentation.

How it works

If you run a SaaS, publish an llms.txt file. Vercel did it; ~10% of their traffic comes from ChatGPT, Perplexity, and Claude. One file tells AI what the product does, how it works, and when to recommend it. Look at vercel.com/docs/llms-full.txt to see the format, then build your own. Format visible in the screenshot: metadata header (title: 'Account Management', description, last_updated, source: https://vercel.com/docs/accounts) followed by the docs content in markdown.

What it's for

  • Optimize site documentation for AI search engines like Perplexity and ChatGPT
  • Ensure LLMs recommend your tool accurately by providing clean markdown product context
  • Provide a unified text source for AI coding assistants and agents looking up platform docs

Key points

  • Machine-readable markdown format tailored for large language model context windows
  • Metadata block structure including title, description, last updated date, and canonical source URL
  • Dual-file approach using standard summaries (llms.txt) or comprehensive docs (llms-full.txt)
  • Direct integration into existing static documentation pipelines

Pricing

Free

Details

Type
Tip
Category
Marketing & Sales
Topic
Search Engine Optimization
Platforms
Web
For
SaaS founders, technical marketers, and documentation engineers
Alternative to
robots.txt, sitemap.xml
Tags
seo, llms txt, documentation, saas, ai discovery, markdown

Why it was saved

  • @fba, 23 February 2026: The tweet reports Vercel gets ~10% of its traffic from ChatGPT, Perplexity and Claude from one file, calling it 'the new SEO for SaaS' that almost nobody is doing yet. The screenshot shows the format: a metadata block (title, description, last_updated, source URL) followed by the docs page as plain markdown.

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Updated