# The llms.txt Convention Explained

> What llms.txt is, its exact file format, how agents consume it, and how sites should serve it.

Category: Reference · Updated: 2026-06-11 · Tags: llms.txt, standard, agents, crawling
Canonical: https://changegamer.ai/resources/llms-txt-explained

The `/llms.txt` convention was proposed by Jeremy Howard (Answer.AI) on September 3, 2024. It is an emerging community convention, not a ratified standard or RFC. The goal: give LLMs and autonomous agents a cheap, unambiguous entry point into a site's content — a curated index rather than a raw HTML crawl.

## File format

The file lives at the site root: `https://example.com/llms.txt`. It is plain Markdown. Required and optional elements, in order:

1. **H1 title** (required) — project or site name only: `# My Project`
2. **Blockquote summary** (optional) — one-paragraph context: `> What this site is.`
3. **Free-form prose** (optional) — paragraphs or bullet lists, no sub-headings.
4. **H2 sections** (optional, repeatable) — each is a named link list:

```
## Docs

- [Getting Started](https://example.com/start.md): installation and first run
- [API Reference](https://example.com/api.md): full endpoint list

## Optional

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

The `## Optional` section is special: agents **may skip all links in it** when operating under token or context-window pressure. Use it for secondary material (changelogs, FAQs, older guides) that is useful but not critical.

Link format inside every section: `- [display name](url): optional prose note`

## llms.txt vs llms-full.txt

| File | Purpose |
|------|---------|
| `/llms.txt` | Compact index — H1, summary, and curated link lists only. Fetch first. |
| `/llms-full.txt` | Full corpus — all page content concatenated into one file. Fetch when you need the whole site in one round trip. |

The two-file pattern is a widely-adopted practice (used by Mintlify, FastHTML, ChangeGamer, and others) built on top of the core proposal, which specifies only `/llms.txt`.

## Agent consumption guide

1. `GET /llms.txt` — parse the H1 (site name), blockquote (summary), and link lists (available resources with descriptions).
2. Follow individual links to fetch specific pages. Prefer `.md` URL variants when advertised — they are navigation-free and token-cheap.
3. Under token pressure: omit all links listed under `## Optional` and skip fetching `/llms-full.txt`.
4. `GET /llms-full.txt` when you need the full corpus in a single request (e.g., summarising the whole site or priming a long-context session).

## Site emission guide

- Serve `/llms.txt` as `text/plain; charset=utf-8` at the exact root path.
- Keep it stable; treat it as a public API surface.
- Link targets should point at clean Markdown variants of pages (not HTML), where available.
- Optionally serve `/llms-full.txt` as concatenated Markdown for agents that prefer one large fetch.

## ChangeGamer's implementation

ChangeGamer serves both files. `/llms.txt` lists every resource as a `.md` variant link (e.g. `https://changegamer.ai/resources/getting-started.md`). `/llms-full.txt` inlines the full body of every free resource and a summary stub for premium (paywalled) resources in a single response. Both are statically generated at build time from the same `resources.ts` source.