Definition

What is llms.txt?

llms.txt is a plain markdown file served at the root of a site, such as example.com/llms.txt. It gives an AI agent a short description of what the site covers and a curated list of links to the pages worth reading, so the agent can find the right documentation without crawling a JavaScript shell or guessing at a sitemap. Jeremy Howard proposed the format in September 2024.

The format

The file is markdown, and the convention is loose. An H1 with the project name comes first, then an optional blockquote summary, then H2 sections holding bullet lists of links. Each bullet is a markdown link followed by a colon and a one-line description of what the linked page contains.

A section headed Optional marks links an agent can skip when it is working with a limited context budget. Nothing enforces any of this. A file that returns 200 with a plausible index is what the AI Agent Readiness Test counts.

# Example API

> Send transactional email over HTTP.

## Docs

- [Quickstart](https://example.com/docs/quickstart.md): Send the first message in five steps.
- [Rate limits](https://example.com/docs/limits.md): Per-plan quotas and the 429 response.

## Optional

- [Changelog](https://example.com/changelog.md): Release history.

llms.txt and llms-full.txt are different files

llms.txt is an index. It points at pages and stays small enough to read in one request. llms-full.txt is the whole corpus concatenated into a single markdown file, which can run to hundreds of kilobytes.

An agent with a large context window can load llms-full.txt and skip the fetching entirely. An agent working against a budget reads llms.txt and fetches only what the task needs. The two serve different readers, which is why the test scores them separately at 10 points each.

llms.txt is not robots.txt

robots.txt tells a crawler which paths it may request. It is a permission file, and it is enforced by convention among crawlers that choose to honour it.

llms.txt grants no permission and blocks nothing. It is an invitation that says which pages are worth reading. A site can serve both, and most sites that serve llms.txt also serve robots.txt.

How common is it?

Adoption among the products tested so far is recorded on the grades table, alongside the four other agent surface checks. The count updates as each report publishes.

The file is cheap to publish and it makes the markdown mirror discoverable, which is the part of the surface an agent uses most directly. Several documentation platforms generate llms.txt for their customers, so a team can end up serving one without having decided to.

Adoption across the products tested

95 of the 97 products tested serve an llms.txt, and 61 serve an llms-full.txt. 61 serve both.

Mailgun serves llms.txt
Resend serves llms.txt
Stripe serves llms.txt
Browserbase serves llms.txt
Airbyte serves llms.txt
Arcade.dev serves llms.txt
CARTO serves llms.txt
Composio serves llms.txt
Convex serves llms.txt
Daytona serves llms.txt
DuckDB serves llms.txt
E2B serves llms.txt
Felt serves llms.txt
Firecrawl serves llms.txt
LangChain serves llms.txt
Railway serves llms.txt
Ably serves llms.txt
Amp serves llms.txt
Baseten serves llms.txt
Blacksmith serves llms.txt
Cline serves llms.txt
CodeRabbit serves llms.txt
CopilotKit serves llms.txt
DeepInfra serves llms.txt
Deno serves llms.txt
ElevenLabs serves llms.txt
Exa serves llms.txt
Expo serves llms.txt
FastMCP serves llms.txt
Fused serves llms.txt
Hermes Agent serves llms.txt
Inkeep serves llms.txt
Letta serves llms.txt
Mapbox serves llms.txt
Massive.com serves llms.txt
Mem0 serves llms.txt
Merge serves llms.txt
MiniMax serves llms.txt
MotherDuck serves llms.txt
n8n serves llms.txt
Neo4j serves llms.txt
Neon serves llms.txt
OpenCode does not serve llms.txt
Orkes serves llms.txt
Ory serves llms.txt
Overture Maps serves llms.txt
Radar serves llms.txt
Recall.ai serves llms.txt
Redis serves llms.txt
Reducto serves llms.txt
Roboflow serves llms.txt
Runpod serves llms.txt
Runware serves llms.txt
Speechmatics serves llms.txt
Stream serves llms.txt
Stytch serves llms.txt
SurrealDB serves llms.txt
Tavily serves llms.txt
TileDB does not serve llms.txt
Tinybird serves llms.txt
Trigger.dev serves llms.txt
TrueFoundry serves llms.txt
Union.ai serves llms.txt
Unstructured serves llms.txt
Vapi serves llms.txt
Vectara serves llms.txt
Warp serves llms.txt
Zep serves llms.txt
Zilliz Cloud serves llms.txt
AssemblyAI serves llms.txt
Clerk serves llms.txt
ClickHouse serves llms.txt
Deepgram serves llms.txt
Doppler serves llms.txt
fal.ai serves llms.txt
Linear serves llms.txt
LiveKit serves llms.txt
LlamaIndex serves llms.txt
Mastra serves llms.txt
Middesk serves llms.txt
Mux serves llms.txt
Netlify serves llms.txt
Notion serves llms.txt
Perplexity serves llms.txt
Persona serves llms.txt
Plaid serves llms.txt
PostHog serves llms.txt
Postman serves llms.txt
Sentry serves llms.txt
Supabase serves llms.txt
Together AI serves llms.txt
Vercel serves llms.txt
WorkOS serves llms.txt
Cartesia serves llms.txt
Courier serves llms.txt
Honeycomb serves llms.txt
Metronome serves llms.txt

Every score and surface check in one table

Common questions about llms.txt

Where does llms.txt go?

At the root of the domain serving the docs, so example.com/llms.txt or docs.example.com/llms.txt. An agent looks for it at the root and does not search for it elsewhere.

Should the links point at .md URLs?

Point them at markdown when a markdown mirror exists. An agent reading an HTML page has to strip navigation, scripts, and styling before it reaches the content, and a .md URL removes that step.

How large should llms.txt be?

Small enough to read in one request. It is an index, so it holds links and one-line descriptions. Put the full text in llms-full.txt instead.

Put another docs site through the battery.

Nominate a docs site