Build the Documentation

NeMo Lens documentation is authored as MDX under docs/ and built with Fern. The Fern configuration, version navigation, and local commands live under docs/fern/.

Prerequisites

Install Node.js 20 or newer. Docker is also required when generating the Python API reference from a local checkout.

The Fern CLI does not need to be installed globally. The npm scripts run the version pinned in docs/fern/fern.config.json.

Validate the Documentation

Generate the Python API reference from the local source tree, then run Fern’s validation:

$
npm --prefix docs/fern run generate:library:local
$
npm --prefix docs/fern run check

The local generator writes API pages under docs/fern/product-docs/. Generated pages are ignored by Git and sanitized automatically for Fern MDX compatibility.

Run a Local Preview

Sign in to the NVIDIA Fern organization before starting the development server so Fern can load the shared NVIDIA theme:

$
npm --prefix docs/fern run login
$
npm --prefix docs/fern run dev

The preview is available at http://localhost:3000.

For a hosted preview, export the Fern token and run:

$
export FERN_TOKEN="$DOCS_FERN_TOKEN"
$
npm --prefix docs/fern run preview

Documentation Layout

docs/
├── index.mdx
├── get-started/
├── user-guide/
├── design/
├── observability/
├── developer/
└── fern/
    ├── docs.yml
    ├── fern.config.json
    ├── package.json
    ├── product-docs/                  # generated and ignored
    └── versions/
        ├── nightly.yml                # points to top-level docs
        ├── 0.1.0.yml                  # points to frozen 0.1.0 pages
        └── 0.1.0/pages/               # stable snapshot

The top-level MDX files are the nightly documentation and should be updated on normal documentation pull requests. The 0.1.0 tree is a frozen stable snapshot and should change only for an intentional documentation backport.

Writing Conventions

• Use .mdx files with lowercase, hyphenated filenames.
• Put the page title and optional description in YAML frontmatter.
• Use version-agnostic internal links such as /user-guide/sampling.
• Use fenced code blocks with a language tag.
• Use Fern components such as <Note> and <Warning> for callouts.
• Escape angle brackets in inline code as < and > when required by MDX.

Add a New Page

1. Add the MDX file under the appropriate top-level docs/ section.
2. Register the page in docs/fern/versions/nightly.yml using a path relative to that file, such as ../../user-guide/my-feature.mdx.
3. Run the local API generation and Fern validation commands.

Do not add new nightly pages under docs/fern/versions/nightly/. Stable version content belongs only under its frozen version directory.

Continuous Integration

Pull requests that modify documentation run Fern configuration, MDX safety, API generation, and offline link checks. A second workflow can publish a hosted preview and update the pull request when PUBLISH_FERN_PREVIEWS=true and DOCS_FERN_TOKEN are configured.

Merges to main that modify docs/ publish the site through Fern. The deployment contains both the frozen 0.1.0 version and the current nightly version.

Troubleshooting