Changelog

Custom robots.txt

You can now serve your own robots.txt at the root of your documentation site by pointing agents.robots-txt at a file in your repo. Use this to opt in or out of specific AI crawlers like GPTBot or ClaudeBot, gate sensitive sections from indexing, or signal training and search preferences with the Cloudflare Content Signals Policy. Your file is served verbatim at /robots.txt, and Fern appends a managed block disallowing internal API routes after your content.

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agents:
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  robots-txt: ./robots.txt

Multi-source docs

Multi-source docs lets each team publish independently to a shared custom domain — for example, docs.nvidia.com spans sub-paths like /nvcf, /brev, and /aiperf, each owned by a different product team and repository.

Set multi-source: true on the instance and reference a global theme for consistent branding across repositories.

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global-theme: my-org-theme
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instances:
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  - url: example.docs.buildwithfern.com/product-a
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    custom-domain: docs.example.com/product-a
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    multi-source: true

API catalog discovery

AI agents, MCP clients, and API catalog crawlers can now discover your APIs automatically. Every Fern Docs site exposes a standards-based (RFC 9727) /.well-known/api-catalog endpoint generated from your visible API Reference navigation.

Custom URL actions on the Prompt component

You can now point <Prompt> actions at any AI tool, not just Cursor, Claude, and ChatGPT. Send readers to Perplexity, your own internal AI assistant, or any other URL.

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<Prompt
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  title="Generate a TypeScript SDK"
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  actions={[
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    { label: "Open in Perplexity", url: "https://www.perplexity.ai/search?q={prompt}", icon: "magnifying-glass" },
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    "cursor"
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  ]}
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>
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Generate a TypeScript SDK from my OpenAPI spec. Follow the [TypeScript SDK quickstart](https://buildwithfern.com/learn/sdks/generators/typescript/quickstart.md).
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</Prompt>

Redesigned dynamic OG images

Dynamic OG images have a new layout with fine-grained control over the logo variant, text and background colors, and which elements appear (section, description, URL, gradient).

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metadata:
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  og:dynamic: true
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  og:dynamic:background-image: ./images/og-background.png
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  og:dynamic:text-color: "#1a1a1a"
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  og:dynamic:background-color: "#ffffff"
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  og:dynamic:logo-color: dark
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  og:dynamic:show-logo: true
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  og:dynamic:show-section: true
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  og:dynamic:show-description: true
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  og:dynamic:show-url: true
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  og:dynamic:show-gradient: true

Prompt component

The <Prompt> component displays an AI prompt card with a title, icon, copy button, and optional “Open in” action buttons. Add it to any page so readers can copy instructions or open them directly in Cursor, Claude, or ChatGPT.

Use it in tutorials, quickstarts, migration guides, or any page where you want readers to hand off a task to an AI assistant — for example, scaffolding a project, generating an SDK, or applying a code change.

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<Prompt
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  title="Create a docs site"
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  icon="rocket"
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  actions={["cursor", "claude", "chatgpt"]}
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>
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You are a **docs setup assistant**. Help the user create and publish a new docs site.
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Follow the [Quickstart guide](https://buildwithfern.com/learn/docs/getting-started/quickstart) step by step.
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</Prompt>

Global themes

Define your documentation branding in a single control repository and share it across multiple sites. Use the fern docs theme CLI commands to export, upload, and manage themes, then reference a theme by name in any child repository’s docs.yml with the global-theme property.

“Connect to Claude Code” page action

Fern Docs sites with Ask Fern enabled now display a “Connect to Claude Code” button alongside existing page actions. Clicking the button copies a claude mcp add command. Readers can paste it into their terminal to register your site’s MCP server with Claude Code.

The action is enabled by default and can be toggled off with page-actions.options.claude-code: false in docs.yml.

Clean up GitHub Actions preview deployments on merge

The GitHub Actions preview workflow now has an optional companion cleanup-preview.yml workflow that deletes a pull request’s preview deployment once the PR merges, so stale previews don’t linger.

To adopt this workflow, add .github/workflows/cleanup-preview.yml alongside your existing preview workflow.

Clean up GitLab preview deployments on merge

The updated GitLab CI/CD pipeline now includes a cleanup_preview stage that deletes a merge request’s preview deployment once the MR merges into the default branch, so stale previews don’t linger.

To adopt this workflow, replace your .gitlab-ci.yml file with the updated version.

Target the logo from custom scripts

<Fern.Logo /> now renders with a data-fern-logo attribute so custom scripts can target the logo with document.querySelector('#fern-header [data-fern-logo]'). Use this to rewrite the logo’s href on certain pages or modify other behavior.

Mobile table of contents bar

Pages using the guide and overview layouts can now display a sticky table of contents bar below the header on mobile and tablet viewports. The bar shows a scroll progress indicator and the current heading, and expands to the full table of contents when tapped.

Enable it by adding mobile-toc: true under layout in docs.yml:

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layout:
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  mobile-toc: true

AI search model update

Ask Fern now uses Claude 4.6 Sonnet and Claude 4.5 Haiku.

Link to API Reference sections with api: syntax

The api: link syntax now supports linking to the root of an API Reference section. Use api:apiName to create a link that resolves to the landing page of a specific API Reference at build time. This is useful when your project has multiple APIs.

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Explore the [Plant Store API](api:plant-store) reference.