> ## Documentation Index > Fetch the complete documentation index at: https://www.mintlify.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # llms.txt > Automatically generate llms.txt and llms-full.txt files so AI tools like ChatGPT and Claude can index and understand your documentation. export const PreviewButton = ({children, href}) => { return {children} ; }; The [llms.txt file](https://llmstxt.org) is an industry standard that helps large language models (LLMs) index content more efficiently, similar to how a sitemap helps search engines. AI tools can use this file to understand your documentation structure and find content relevant to user queries. Mintlify automatically hosts an `llms.txt` file at the root of your project that lists all available pages in your documentation. This file is always up to date and requires zero maintenance. You can optionally add a custom `llms.txt` file to the root of your project. Authentication affects `llms.txt` and `llms-full.txt` differently depending on your site configuration: * **Fully authenticated sites**: Both files require authentication. AI tools that cannot authenticate cannot access them. * **Partially authenticated sites**: Both files are publicly accessible, but only list public pages and exclude pages restricted to user groups. For more information on how authentication affects AI features, see [Feature availability](/docs/deploy/authentication-setup#feature-availability). View your `llms.txt` by appending `/llms.txt` to your documentation site's URL. Mintlify also hosts the file at `/.well-known/llms.txt` for compatibility with tools that follow the `.well-known` convention. Open the llms.txt for this site. Mintlify adds HTTP headers to every page response so AI tools can discover your `llms.txt` files and other agent resources without prior knowledge of their location: * `Link`: Follows the standard HTTP `Link` header format for resource discovery. Advertises `llms.txt`, `llms-full.txt`, your API catalog, [MCP server card](/docs/ai/model-context-protocol#discovery-endpoint), [agent card](/docs/ai/skillmd#agent-card), and [agent skills index](/docs/ai/skillmd#skills-discovery-endpoints). * `X-Llms-Txt`: A convenience header for tools that check for `llms.txt` support. ```http Response headers theme={null} Link: ; rel="llms-txt", ; rel="llms-full-txt", ; rel="api-catalog", ; rel="mcp-server-card", ; rel="agent-card", ; rel="agent-skills" X-Llms-Txt: /llms.txt ``` Sites that use authentication also advertise their OAuth protected resource metadata with `rel="oauth-protected-resource"`. If you serve your documentation under a base path, every advertised path includes that prefix. ## Structure of the llms.txt file An `llms.txt` file is a plain Markdown file that contains: * **Site title** as an H1 heading. * **Site description** as a blockquote summary below the title, sourced from the `description` field in your `docs.json` configuration. * **Custom agent instructions** as an `Agent Instructions` block after the description, if you set [`markdown.instructions`](/docs/ai/markdown-export#custom-agent-instructions) in your `docs.json`. * **Structured content sections** with links and a description of each page in your documentation. * **API specification links** to your OpenAPI and AsyncAPI specs, if your documentation includes them. * **External links** in an `Optional` section, for any absolute URLs in your navigation. The `llms.txt` file lists your pages in the order they appear in your `docs.json` navigation. Pages that aren't in your navigation but that `seo.indexing: "all"` includes appear last, in alphabetical order. Page links in the `llms.txt` file include a `.md` extension so AI tools can fetch the Markdown version of each page directly. Each page's description comes from the `description` field in its frontmatter. Mintlify uses the first paragraph of the description and truncates it at 300 characters. Pages without a `description` field appear in the `llms.txt` file without a description. Both `llms.txt` and `llms-full.txt` list pages from your default language and default version. They exclude [hidden pages](/docs/organize/hidden-pages) and pages with `noindex: true` in their frontmatter unless you set `seo.indexing: "all"` in your `docs.json`. This structured approach allows LLMs to efficiently process your documentation at a high level and locate relevant content for user queries, improving the accuracy and speed of AI-assisted documentation searches. Automatically generated `llms.txt` index files cannot exceed 100,000 characters. For large documentation sites, Mintlify splits the index into linked files under `/_llms/` so agents can discover every page without loading one oversized file. This limit does not apply to `llms-full.txt`. If you use a reverse proxy or maintain a path allowlist, forward `/_llms/*` in addition to `/llms.txt` so agents can follow the generated index links. For documentation hosted at a base path, forward `/_llms/*` instead. Mintlify-managed custom domains do not require additional configuration. See [Reverse proxy](/docs/deploy/reverse-proxy#routing-configuration) for routing guidance. ```mdx Example llms.txt theme={null} # Site title > A brief description of the documentation site. ## Docs - [API](https://example.com/docs/api.md): Endpoint list and usage - [Install](https://example.com/docs/install.md): Setup steps - [Getting started](https://example.com/docs/start.md): Intro guide ## OpenAPI Specs - [openapi](https://example.com/docs/openapi.json) ## AsyncAPI Specs - [asyncapi](https://example.com/docs/asyncapi.yaml) ## Optional - [Community](https://example.com/community) ``` ## llms-full.txt The `llms-full.txt` file combines your entire documentation site into a single file as context for AI tools and LLM indexing. Each page appears as its title, source URL, description, and full Markdown content. Mintlify automatically hosts an `llms-full.txt` file at the root of your project. View your `llms-full.txt` by appending `/llms-full.txt` to your documentation site's URL. Mintlify also hosts the file at `/.well-known/llms-full.txt` for compatibility with tools that follow the `.well-known` convention. Open the llms-full.txt for this site. ## Custom files To add a custom `llms.txt` or `llms-full.txt` file, create an `llms.txt` or `llms-full.txt` file at the root of your project. Adding a custom file overrides the automatically generated file of the same name. If you delete a custom file, Mintlify restores the automatically generated file. Your custom `llms.txt` or `llms-full.txt` file must have a site title as an H1 heading. Other content is optional. See [Format](https://llmstxt.org/#format) in the `llms.txt` specification for more information on optional sections and best practices. ## Related topics - [GEO guide: Optimize docs for AI search and answer engines](/docs/guides/geo.md) - [Glossary](/docs/reference/glossary.md) - [Mintlify CLI command reference](/docs/cli/commands.md)