Agent Ready HTML

Read the Docs: vendor profile

In short

Read the Docs relays Cloudflare's markdown conversion to any request carrying Accept: text/markdown, on every documentation domain it hosts. A project ships its own llms.txt in its build, because the service writes none. Whether page text reaches the initial HTML depends on the doc tool behind the project. Business starts at $50 a month.

At a glance

standards.txt read-the-docs

llms-txt               = partial
markdown-negotiation   = supports
markdown-twin          = no statement
initial-html           = partial
real-404               = supports
vary-accept            = partial

2 supports, 3 partial or announced, 1 no statement.

Read the Docs Docs platform

Build and hosting service for Sphinx, MkDocs and other static doc tools. Serves the tool's HTML, answers Accept: text/markdown on every hosted domain through Cloudflare, and serves a project's own llms.txt, robots.txt, sitemap.xml and 404.html from the default version.

Type
Docs platform
Home page
about.readthedocs.com, answered HTTP 200 on 2026-11-05
Last read
5 November 2026

What it does for this layer

  • Read the Docs converts hosted pages to markdown for any request carrying Accept: text/markdown, switched on for every documentation domain it hosts with no project setting; browsers still get HTML. [primary source] source, read 5 November 2026.
  • Read the Docs credits Cloudflare's Markdown for agents conversion for its markdown responses; the documented sample response shows vary: accept plus an x-markdown-tokens count and a content-signal header. [primary source] source, read 5 November 2026.
  • Read the Docs does not write llms.txt for a project; it serves a file the project's build puts in its output, at the domain root, taken from the default version, and does the same for llms-full.txt. [primary source] source, read 5 November 2026.
  • For generating llms.txt the Read the Docs docs point Sphinx users to the sphinx-llm extension or html_extra_path, and MkDocs users to the mkdocs-llmstxt plugin or docs_dir. [primary source] source, read 5 November 2026.
  • Root-level llms.txt and llms-full.txt serving was announced on the Read the Docs blog on 2026-02-11 by Eric Holscher. [primary source, 2026-02-11] source, read 5 November 2026.
  • A Read the Docs post of 2026-02-11 introduced Agent Skills for API v3 and .readthedocs.yaml work (installable with npx skills add readthedocs/skills) after the team tried MCP servers and llms.txt. [primary source, 2026-02-11] source, read 5 November 2026.
  • Read the Docs uses a project's own 404.html or 404/index.html as the not-found page, checking the current version first and then the default version; it maintains the sphinx-notfound-page extension for Sphinx. [primary source] source, read 5 November 2026.
  • Read the Docs generates sitemap.xml per project covering public, non-hidden versions sorted by semantic version; a custom sitemap.xml in the default version's output replaces it as-is. [primary source] source, read 5 November 2026.
  • The robots.txt that Read the Docs writes by default hides versions marked Hidden and allows all others; projects override it by shipping robots.txt in the default version's build. [primary source] source, read 5 November 2026.
  • Read the Docs hosts output from any tool that writes HTML, so whether a page's text is in the initial HTML depends on the tool: its tools page lists Sphinx and MkDocs next to Docusaurus, VitePress and Antora. [primary source] source, read 5 November 2026.
  • Read the Docs' automated-access policy asks crawlers to stay under 4 requests per second, to put a domain or email in the user agent, and points bots to markdown responses. [primary source] source, read 5 November 2026.
  • Read the Docs Business lists Basic at $50, Advanced at $150 and Pro at $250 per month with a 30-day trial; Enterprise starts at $10,000 per year. Read the Docs Community is free and ad-supported for open source. [primary source, 2026-11-05] source, read 5 November 2026.
  • On 2026-11-05 an Accept: text/markdown request to a page under docs.readthedocs.com/platform/stable/ returned 200 text/markdown (3,822 bytes, Vary: Accept-Encoding, accept), while the HTML response for the same URL carried only Vary: Accept-Encoding. [observed, 2026-11-05] source, read 5 November 2026.
  • On 2026-11-05 a community project, requests.readthedocs.io/en/latest/, also answered Accept: text/markdown with 200 text/markdown, while a .md suffix on a docs.readthedocs.com page returned 404. [observed, 2026-11-05] source, read 5 November 2026.
  • On 2026-11-05 a made-up .html path under docs.readthedocs.com/platform/stable/reference/ returned HTTP 404 with the project's HTML not-found page. [observed, 2026-11-05] source, read 5 November 2026.

Products and plans

Plans and prices as the vendor's own pages showed them on the date read.
ProductWhat it isPriceAs ofSource
Read the Docs CommunityFree, ad-supported hosting at readthedocs.io for open source projects with public repositories.Free
Free for open-source software; ads supported.		2026-11-05source
Read the Docs BusinessPaid hosting for private and public docs with team management, custom domains and SSO.From USD 50
Basic $50 per month billed monthly (annual available); Advanced $150; Pro $250; Enterprise from $10,000 per year.		2026-11-05source

Standards

The six standards this site tracks; no statement means the pages read said nothing.
StandardStatusWhat the vendor's pages saySource
llms-txtpartialServes a project-supplied llms.txt and llms-full.txt at the root; the build tool or a plugin must generate them.source
markdown-negotiationsupportsAccept: text/markdown returns markdown on all hosted domains, no configuration.source
markdown-twinno statementNo .md per-page URL found in the llms.txt or Markdown for AI agents docs; a .md suffix on a docs page returned 404 on 2026-11-05.none
initial-htmlpartialHosts the HTML any doc tool outputs; Sphinx and MkDocs write static pages, other tools may not.source
real-404supportsServes the project's 404.html when its servers return a 404 Not Found error.source
vary-acceptpartialDocumented sample shows vary: accept on the markdown response; on 2026-11-05 the HTML response lacked Accept in Vary.source

Checks on its own site

Readings of about.readthedocs.com, the vendor's own website, which describe that site and not the product.
ReadingResultDate
Home page requestHTTP 200; H1 in the initial HTML: yes; 693 words; 0 JSON-LD blocks2026-11-05
Request with Accept: text/markdownHTTP 200, text/markdown, Vary: Accept-Encoding, accept2026-11-05
/llms.txt at the host rootHTTP 404, text/html, 14 KB2026-11-05
A made-up pathHTTP 4042026-11-05
Ora score, cachedNot available: GET /api/score returned 404 DOMAIN_NOT_SCANNED2026-11-05
Cloudflare keyless scan27, L1 Basic Web Presence2026-11-05

What it does not do

  • Read the Docs adds no prerendering of its own, so a client-rendered single-page app uploaded from any doc tool reaches crawlers as that tool's HTML shell.

Related pages on this site

Sources

  1. Read the Docs: home page https://about.readthedocs.com/, read 5 November 2026
  2. Markdown for AI agents: Read the Docs user documentation https://docs.readthedocs.com/platform/stable/reference/markdown-for-agents.html, read 5 November 2026
  3. llms.txt support: Read the Docs user documentation https://docs.readthedocs.com/platform/stable/reference/llms-txt.html, read 5 November 2026
  4. Serve llms.txt from your docs - Read the Docs https://about.readthedocs.com/blog/2026/02/llms-txt-support/, read 5 November 2026
  5. Agent skills for the Read the Docs now available - Read the Docs https://about.readthedocs.com/blog/2026/02/readthedocs-skills-api-config/, read 5 November 2026
  6. 404 Not Found pages: Read the Docs user documentation https://docs.readthedocs.com/platform/stable/reference/404-not-found.html, read 5 November 2026
  7. Sitemap support: Read the Docs user documentation https://docs.readthedocs.com/platform/stable/reference/sitemaps.html, read 5 November 2026
  8. robots.txt support: Read the Docs user documentation https://docs.readthedocs.com/platform/stable/reference/robots.html, read 5 November 2026
  9. Popular documentation tools: Read the Docs user documentation https://docs.readthedocs.com/platform/stable/intro/doctools.html, read 5 November 2026
  10. Automated access to Read the Docs: Read the Docs user documentation https://docs.readthedocs.com/platform/stable/automated-access.html, read 5 November 2026
  11. Pricing - Read the Docs https://about.readthedocs.com/pricing/, read 5 November 2026

Last reviewed 5 November 2026