--- title: "Fern: vendor profile: Agent Ready HTML" description: "Fern, a docs platform: 4 of 6 standards stated as supported, 15 sourced facts, dated plans and what it does not do. Read 2026-11-05." canonical: https://agentreadyhtml.com/vendors/fern/ site: "Agent Ready HTML" last_updated: 2026-11-05 section: "Vendors" --- # Fern: vendor profile: Agent Ready HTML > Fern, a docs platform: 4 of 6 standards stated as supported, 15 sourced facts, dated plans and what it does not do. Read 2026-11-05. Source: https://agentreadyhtml.com/vendors/fern/ Site: Agent Ready HTML Last reviewed: 2026-11-05 # Fern: vendor profile In short Fern joined Postman on 2026-01-08 and keeps its own brand. Its docs sites are prebuilt static pages that ship llms.txt, .md copies and markdown for Accept: text/markdown. A missing .md address answered 200 with similar pages. The free plan allows 1,000 pages; custom React components need Enterprise. ## At a glance **standards.txt** fern ```text llms-txt = supports markdown-negotiation = supports markdown-twin = supports initial-html = supports real-404 = partial vary-accept = no statement ``` 4 supports, 1 partial or announced, 1 no statement. **Fern** Docs platform Fern, now a Postman company, builds API docs sites that are prebuilt as static pages at the edge and ship llms.txt, .md copies, markdown on Accept: text/markdown, JSON-LD, sitemaps and an agent directive on every page. Type [Docs platform](https://agentreadyhtml.com/vendors/by-type/docs-platform/) Operator, as the facts below state it Postman Headquarters United States Home page [buildwithfern.com](https://buildwithfern.com/), answered HTTP 200 on 2026-11-05 Last read 5 November 2026 ## What it does for this layer - Fern announced on 2026-01-08 that it has joined Postman, that the entire Fern team moved to Postman and that Fern keeps running as an independent product under its own brand. \[primary source, 2026-01-08\] [source](https://buildwithfern.com/post/postman-acquires-fern), read 5 November 2026. - Fern dates its founding to 2022, when it set out to help businesses ship better public APIs, and says both Fern Docs and its SDK generator are open source. \[primary source\] [source](https://buildwithfern.com/post/postman-acquires-fern), read 5 November 2026. - Fern generates meta tags, social previews, canonical URLs, JSON-LD structured data, clean slugs and llms.txt content for every indexable page with no configuration. \[primary source\] [source](https://buildwithfern.com/learn/docs/seo/overview), read 5 November 2026. - Fern's sitemap.xml gives each page a lastmod value that changes only when the content changes, so whitespace or capitalization edits do not bump it. \[primary source\] [source](https://buildwithfern.com/learn/docs/seo/overview), read 5 November 2026. - Fern serves a default robots.txt that allows all crawlers; a custom file set with the agents.robots-txt key in docs.yml is served verbatim with a Fern-managed block appended. \[primary source\] [source](https://buildwithfern.com/learn/docs/seo/robots-txt), read 5 November 2026. - Fern's and tags split one page between readers and agents, so llms-only text reaches llms.txt and the .md copy but stays hidden in the rendered page. \[primary source\] [source](https://buildwithfern.com/learn/docs/ai-features/customize-llm-output), read 5 November 2026. - Fern prepends a default directive to every page's agent markdown that points to the .md URLs and llms.txt; the page-directive key in docs.yml replaces it or turns it off. \[primary source\] [source](https://buildwithfern.com/learn/docs/ai-features/agent-directives), read 5 November 2026. - Fern renders custom React components on the server so their output lands in the HTML, but custom components are an Enterprise plan feature. \[primary source\] [source](https://buildwithfern.com/learn/docs/customization/custom-react-components), read 5 November 2026. - Fern's self-hosting, an Enterprise feature, ships the docs site as the fernenterprise/fern-self-hosted Docker image, and offline AI chat was still in development. \[primary source\] [source](https://buildwithfern.com/learn/docs/self-hosted/overview), read 5 November 2026. - Fern's post of 2026-10-26 says the old renderer sent each page twice, as HTML and as a data payload worth 72% to 75% of the HTML, and the new static pages are 2 to 4 times smaller. \[primary source, 2026-10-26\] [source](https://buildwithfern.com/post/static-docs), read 5 November 2026. - Fern's changelog of 2026-10-08 turned on dynamic Open Graph images by default for sites with no site-wide og:image, switchable off with og:dynamic: false. \[primary source, 2026-10-08\] [source](https://buildwithfern.com/learn/docs/changelog), read 5 November 2026. - Fern's free Docs plan allows 10 team members, 1,000 pages, 250 AI credits and 2,000 page generations a month, with custom domain or subpath, Ask Fern and an MCP server. \[primary source, 2026-11-05\] [source](https://buildwithfern.com/pricing), read 5 November 2026. - A curl GET of a made-up .md URL under buildwithfern.com/learn/docs on 2026-11-05 returned HTTP 200 text/plain listing similar pages, while the HTML path returned 404. \[observed, 2026-11-05\] [source](https://buildwithfern.com/learn/docs/changelog), read 5 November 2026. - Served through Cloudflare, Fern's text/markdown response for the SEO overview page named Accept as its Vary value on 2026-11-05. \[observed, 2026-11-05\] [source](https://buildwithfern.com/learn/docs/seo/overview), read 5 November 2026. - The initial HTML of Fern's SEO overview page held a JSON-LD block typed TechArticle, BreadcrumbList and WebSite when fetched with curl on 2026-11-05. \[observed, 2026-11-05\] [source](https://buildwithfern.com/learn/docs/seo/overview), read 5 November 2026. ## Products and plans | Product | What it is | Price | As of | Source | | --- | --- | --- | --- | --- | | Fern Docs Free | Hosted docs with guides, API references, changelogs, custom domain or subpath, Ask Fern, Fern Agent and an MCP server. | Free; Free forever, $0 per month; 1,000 pages, 250 AI credits a month | 2026-11-05 | source | | Fern Docs Enterprise | Adds SSO, SCIM, RBAC, custom CSS, JavaScript and React components, multiple repos and self-hosting. | Quote on request; Custom pricing | 2026-11-05 | source | ## Standards | Standard | Status | What the vendor's pages say | Source | | --- | --- | --- | --- | | llms-txt | supports | Fern's SEO overview lists llms.txt output among the defaults generated for indexable pages. | source | | markdown-negotiation | supports | Fern's markdown access page documents content negotiation on the Accept: text/markdown header. | source | | markdown-twin | supports | Each page has .md and .mdx variants per the markdown access docs. | source | | initial-html | supports | Every Fern Docs site is prebuilt as static pages, and custom React components are server-side rendered. | source | | real-404 | partial | HTML paths return 404, but a made-up .md path returned 200 text/plain with similar pages on 2026-11-05. | source | | vary-accept | no statement | No statement on Vary found in the markdown access docs; Fern answered with vary: Accept on 2026-11-05. | source | ## Checks on its own site | Reading | Result | Date | | --- | --- | --- | | Home page request | HTTP 200; H1 in the initial HTML: yes; 2,031 words; 4 JSON-LD blocks | 2026-11-05 | | Request with Accept: text/markdown | HTTP 200, text/html, Vary: Accept-Encoding | 2026-11-05 | | /llms.txt at the host root | HTTP 200, text/plain, 44 KB, starts with an H1 | 2026-11-05 | | A made-up path | HTTP 404 | 2026-11-05 | | Ora score, cached | 72, grade B | 2026-11-04 | | Cloudflare keyless scan | 27, L1 Basic Web Presence | 2026-11-05 | | Shared crawl row | outside the ranked slice; home page HTTP 200; H1 in the HTML: yes; 1,400 words; JSON-LD types: Organization, WebSite; answers markdown: no; made-up path HTTP 404; llms.txt valid: yes | 2026-11-04 | ## What it does not do - A custom robots.txt on Fern is never served alone, since Fern appends its own User-Agent: \* group and a block for internal API routes. ## Related pages on this site - [Docs platforms in this section](https://agentreadyhtml.com/vendors/by-type/docs-platform/) - [Fern: platform profile and rubric scores](https://agentreadyhtml.com/platforms/fern/) - [The Plain Fetch viewer](https://agentreadyhtml.com/viewer/) ## Sources 1. [Fern: home page](https://buildwithfern.com/) https://buildwithfern.com/, read 5 November 2026 2. [Fern blog: Fern has joined Postman](https://buildwithfern.com/post/postman-acquires-fern) https://buildwithfern.com/post/postman-acquires-fern, read 5 November 2026 3. [Overview of SEO & GEO | Fern Documentation](https://buildwithfern.com/learn/docs/seo/overview) https://buildwithfern.com/learn/docs/seo/overview, read 5 November 2026 4. [Custom robots.txt | Fern Documentation](https://buildwithfern.com/learn/docs/seo/robots-txt) https://buildwithfern.com/learn/docs/seo/robots-txt, read 5 November 2026 5. [Customize LLM output | Fern Documentation](https://buildwithfern.com/learn/docs/ai-features/customize-llm-output) https://buildwithfern.com/learn/docs/ai-features/customize-llm-output, read 5 November 2026 6. [Agent directives | Fern Documentation](https://buildwithfern.com/learn/docs/ai-features/agent-directives) https://buildwithfern.com/learn/docs/ai-features/agent-directives, read 5 November 2026 7. [Custom React components | Fern Documentation](https://buildwithfern.com/learn/docs/customization/custom-react-components) https://buildwithfern.com/learn/docs/customization/custom-react-components, read 5 November 2026 8. [Self-hosted documentation | Fern Documentation](https://buildwithfern.com/learn/docs/self-hosted/overview) https://buildwithfern.com/learn/docs/self-hosted/overview, read 5 November 2026 9. [Fern Docs sites are now static, and much faster | Fern](https://buildwithfern.com/post/static-docs) https://buildwithfern.com/post/static-docs, read 5 November 2026 10. [Changelog | Fern Documentation](https://buildwithfern.com/learn/docs/changelog) https://buildwithfern.com/learn/docs/changelog, read 5 November 2026 11. [Pricing | Fern](https://buildwithfern.com/pricing) https://buildwithfern.com/pricing, read 5 November 2026 12. [Markdown access | Fern Documentation](https://buildwithfern.com/learn/docs/ai-features/markdown) https://buildwithfern.com/learn/docs/ai-features/markdown, read 5 November 2026 Last reviewed 5 November 2026 Edition Crawl 2026-11-04 Page updated 2026-11-05 Method How the viewer reads a page, how a file is graded and how a platform is scored: [the method page](https://agentreadyhtml.com/method/).