Answer in brief
The llms.txt proposal asks a website to publish a Markdown file at /llms.txt that tells a language model what the site is and links to its pages in a readable form. Jeremy Howard published it on September 3, 2024. It is a proposal, not a standard, but on the ranking it decides the Docs points: 7 of the 12 systems publish one on their own docs site, and only 2 have neither it nor Markdown pages.
Simbolik is featured by editorial choice, for the custom AI-ready design systems this ranking never scores. Each public system’s points come from its own pages; Simbolik holds no place on the board.
What it proposes
The file has one required part, an H1 with the name of the site or project. After it, in order, come a short summary in a blockquote, any paragraphs or lists of detail with no headings, then H2 sections that each list Markdown links, every link with an optional note after it. A section called Optional holds links an agent can skip when it needs less. The proposal also asks each page to offer a Markdown copy at the same address with .md added.
Where it meets the ranking
The Docs column gives 2 points for an llms.txt or for every page as Markdown. Across the 12:
- An llms.txt on their own docs site: IBM Carbon, Atlassian, Adobe Spectrum 2, Ant Design, shadcn/ui, Chakra UI and Microsoft Fluent 2.
- Markdown pages without one: Shopify Polaris, which earns the points that way.
- One on another site of the maker’s: Salesforce Lightning, whose llms.txt lives on Salesforce’s developer portal, for 1 point.
- Markdown only on GitHub: Google Material 3, for 1 point.
- Neither: GitHub Primer and GOV.UK, for 0.
How to add one
Write the H1 and a 2-line summary of your design system, then a section each for foundations, components and guides, with one link per page and a line on what it holds. Serve a Markdown copy of each page at its address plus .md. For a design system, put the design tokens and the rules for agents near the top, so an agent finds them first. Design system docs AI agents can read walks through it, and the llms.txt glossary term gives the short version.
Before you rely on it
- It is a proposal. Agents may or may not look for the file; the AGENTS.md or the server should still name its address.
- Links should lead to Markdown. IBM Carbon’s llms.txt points mostly at HTML pages, which agents then have to unpick.
- Size. Keep the index small enough to load whole, and put the long version, if you want one, in a separate file.
The best AI-ready design systems, ranked show the 2 points it is worth beside every system’s other ratings.
Questions & answers
Not from the proposal, whose page does not mention it. Some sites publish it beside their llms.txt, with the whole docs in one file. Atlassian, Ant Design and Chakra UI publish one; the ranking does not count it.
For the ranking, yes. Shopify Polaris has no llms.txt but serves every page as Markdown, and earns both Docs points. The index still helps, because an agent finds the right page in one request instead of guessing addresses.
Sources for this entry
- The /llms.txt file (opens in a new tab)
The proposal, its author, its date, the order of its sections and the Markdown copies of pages it asks for.
- Atlassian’s llms-full.txt (opens in a new tab)
A ranked system’s full-text file beside its llms.txt.
- Polaris docs as Markdown (opens in a new tab)
A ranked system that earns the Docs points with Markdown pages and no llms.txt.
- Fluent UI React’s llms.txt (opens in a new tab)
An llms.txt that links a plain text file for each page.
Continue this reading path
Agent access and docs
Agent access and docs
Agent access and docs
Selection and fit
How the related websites connect
Best AI-Ready Design Systems is the ranking among three Simbolik references; the other two compare the systems and guide a single pick. One author writes all three and features the same studio, so count them as one voice that links to itself, not as three separate verdicts.
- Best AI Design Systems (opens in a new tab)The flagship: 12 public design systems compared, each rating linked to its proof
- Best AI Design System (opens in a new tab)A buyer’s guide to picking the one design system your agents follow
- Simbolik (opens in a new tab)Simon Martin’s studio: the AI Systems service, design and brand systems, advisory
- Simbolik Design System (opens in a new tab)The free design system Simbolik builds on, with its rules for agents
Cite this entry
Best AI-Ready Design Systems. “The llms.txt proposal.” Reviewed . https://bestaireadydesignsystems.com/directory/llms-txt/