// Maintain the NeMo AutoModel Fern docs site under fern/ — add, update, move, or remove pages; manage redirects, slugs, navigation, and version aliases; run validation and previews.
Guide for onboarding new model families into NeMo AutoModel, including architecture discovery, implementation patterns, registration, and validation.
Dev environment setup for NeMo AutoModel — container-based development, uv package management, installation options, environment variables, and common build pitfalls.
CI/CD reference for NeMo AutoModel — pipeline structure, commit and PR workflow, CI failure investigation, and common failure patterns.
Guide for selecting and configuring distributed training strategies in NeMo AutoModel, including FSDP2, Megatron FSDP, DDP, and parallelism settings.
Configure NeMo AutoModel job launches for interactive runs, Slurm clusters, and SkyPilot cloud execution.
Code style and quality rules for NeMo AutoModel — ruff configuration, naming conventions, type hints, docstrings, copyright headers, and the code review checklist.
| name | fern-docs |
| description | Maintain the NeMo AutoModel Fern docs site under fern/ — add, update, move, or remove pages; manage redirects, slugs, navigation, and version aliases; run validation and previews. |
| when_to_use | Editing or adding documentation pages, fixing broken links, renaming a slug, updating the sidebar, adding a redirect, regenerating the API library reference, debugging fern check / broken-link errors, cutting a new version train, 'edit docs', 'add doc page', 'fern check failing', 'preview fails locally'. |
Unified skill for adding, updating, moving, and removing pages on the NeMo AutoModel Fern documentation site at docs.nvidia.com/nemo/automodel.
ALL docs edits happen under fern/. The legacy Sphinx tree at docs/ is read-only reference; do not add new pages there. New pages, release notes, migration guides — everything belongs under fern/versions/nightly/pages/.
Two real content trees, plus a GA alias YAML.
fern/versions/nightly/pages/ — bleeding-edge tree. Every PR lands here. Mounted at the nightly URL slug via nightly.yml.fern/versions/v0.4/pages/ — frozen 0.4.0 GA snapshot. Independent copy of every page. Only changes via deliberate back-port. Mounted at the v0.4 URL slug via v0.4.yml.fern/versions/latest.yml — GA alias. Its path: lines mount the current GA's content (today: ./v0.4/pages/...). Repointed at the next GA's tree when one is cut.The two trees were byte-for-byte identical at the moment 0.4.0 shipped (today, just after the migration), but they will diverge as nightly accumulates post-release edits and v0.4 stays frozen. Default editing target is nightly/. Only touch v0.4/ for explicit back-ports — call out the divergence in the PR description.
Sidebar fidelity rule. Section captions, page titles, and Model Coverage child ordering must match the published v0.4.0 sidebar at docs.nvidia.com/nemo/automodel/latest verbatim. Don't silently shorten a title or reorder siblings — the docs PM and content engineers diff against the published site and any drift is treated as a regression. If you want a shorter sidebar label, change the toctree-derived display name in the source — never just retitle in the MDX.
fern/
├── fern.config.json # Org slug + Fern CLI pin (4.62.4+)
├── docs.yml # Site config: instances, versions, redirects, libraries, theme
├── main.css # NVIDIA-green theme overrides
├── assets/ # Logos and shared SVGs (NVIDIA_dark/light/symbol)
├── components/ # BadgeLinks.tsx, Tag.tsx, CustomFooter.tsx
├── versions/
│ ├── nightly.yml # Nav for bleeding-edge — paths → ./nightly/pages/
│ ├── nightly/pages/ # Bleeding-edge MDX (edited every PR)
│ ├── v0.4.yml # Nav for frozen 0.4.0 — paths → ./v0.4/pages/
│ ├── v0.4/pages/ # Frozen 0.4.0 MDX (back-ports only)
│ └── latest.yml # GA alias — paths → ./v0.4/pages/ today; repointed at next GA cut
└── product-docs/ # GENERATED Python API reference (gitignored)
File URL
───────────────────────────────────────────────────────── ────────────────────────────────────────────
fern/versions/nightly/pages/get-started/installation.mdx /latest/get-started/installation
/v0.4/get-started/installation
/nightly/get-started/installation
Gather: title, target section, filename (kebab-case .mdx), subdirectory under fern/versions/nightly/pages/.
Create the MDX with frontmatter:
---
title: "<Page Title>"
description: "One-line SEO description (or empty string)"
position: 4
---
<body — typically no leading `# H1`; Fern renders the title automatically>
Add a - page: entry to fern/versions/nightly.yml under the right section:, with an explicit slug: if the desired URL differs from the slugified title:
- page: "<Page Title>"
path: ./nightly/pages/<subdir>/<filename>.mdx
slug: <short-url-segment>
Sync the aliases: cp fern/versions/nightly.yml fern/versions/latest.yml && sed -i '' 's|./nightly/pages/|./v0.4/pages/|g' fern/versions/latest.yml.
make docs-check (runs fern check) and verify URL resolves on make docs preview.
grep -rn "<keyword>" fern/versions/nightly/pages/ --include="*.mdx".title: and (if the page is in versions/nightly.yml) update the - page: entry's display label. Re-sync latest.yml and v0.4.yml.git mv the file, update path: in versions/nightly.yml, fix incoming links, re-sync aliases.slug: in the YAML (or rename the file and let the default slug update). Add a redirects: entry in docs.yml so the old URL keeps working.Four things to watch when editing redirects: in fern/docs.yml:
:path* does NOT match the empty-path case. /<basepath>/v0.4/:path*/index.html will not match /<basepath>/v0.4/index.html (where :path* would have to be empty). Each version-root index.html needs its own explicit rule. NeMo Curator (NVIDIA-NeMo/Curator#1938) discovered this when their version-root URLs 404'd. AutoModel ships explicit rules for latest, v0.4, nightly, and the legacy 0.4 form — when you add a new version slug, add four new explicit rules: <slug>/index.html, <slug>/index, plus the same two for any legacy form (e.g. 0.5 → v0.5).docs.nvidia.com/nemo/<product>/latest/) but you didn't migrate into Fern still need to resolve. The pattern: redirect each old slug's URLs to the equivalent path under /latest/ so external bookmarks and search results land on the closest current page instead of 404ing. Five rules per old version: <slug>/index.html, <slug>/index, <slug>/:path*/index.html, <slug>/:path*, <slug>/:path*.html — all destinations /latest/.... AutoModel ships these for 0.3.0, 0.2.0, 0.1.0.:path*/index.html and :path*.html catch-alls.redirects: [] then re-run the redirect generator on top — it replaces the whole redirects: block. Edit by hand or back up the existing rules first.grep -rn "<filename>" fern/versions/nightly/pages/ --include="*.mdx".git rm fern/versions/nightly/pages/<path>.mdx.- page: block from versions/nightly.yml (and re-sync latest.yml / nightly.yml).docs.yml if the URL was public.Request: "Add a fine-tuning guide for Qwen3.6 under Recipes & E2E Examples."
Create fern/versions/nightly/pages/guides/llm/qwen3-6-finetune.mdx:
---
title: "Fine-Tune Qwen3.6"
description: "End-to-end SFT and PEFT recipes for Qwen3.6 on NeMo AutoModel"
---
This guide walks through fine-tuning Qwen3.6 with NeMo AutoModel...
Add to fern/versions/nightly.yml under the Recipes & E2E Examples section, slotted in publication-order with the other fine-tune entries:
- page: "Fine-Tune Qwen3.6"
path: ./nightly/pages/guides/llm/qwen3-6-finetune.mdx
slug: qwen3-6-finetune
cp fern/versions/nightly.yml fern/versions/latest.yml && sed -i '' 's|./nightly/pages/|./v0.4/pages/|g' fern/versions/latest.yml.
make docs-check then make docs to preview at http://localhost:3002/latest/recipes-e2e-examples/qwen3-6-finetune.
Request: "Rename /recipes-e2e-examples/sft-peft to /recipes-e2e-examples/fine-tuning."
Edit versions/nightly.yml, change the slug: on the SFT & PEFT entry from sft-peft to fine-tuning.
Add a redirect to fern/docs.yml:
redirects:
- source: "/:version/recipes-e2e-examples/sft-peft"
destination: "/:version/recipes-e2e-examples/fine-tuning"
grep -rn "/recipes-e2e-examples/sft-peft" fern/versions/nightly/pages/ and update incoming body links.
Re-sync latest.yml and v0.4.yml.
NeMo AutoModel uses Fern-native MDX components. Don't use GitHub > [!NOTE] syntax — it doesn't render in MDX.
| Purpose | Component |
|---|---|
| Neutral aside | <Note>...</Note> |
| Helpful tip | <Tip>...</Tip> |
| Informational callout | <Info>...</Info> |
| Warning | <Warning>...</Warning> |
| Error / danger | <Error>...</Error> |
| Card grid on landing pages | <Cards> with <Card title="..." href="..."> children |
| Card chips ("start here", "5 min") | <Tag variant="primary">label</Tag> — sphinx-design {bdg-*} mapping |
| Header badge rows (PyPI, license, GitHub) | <BadgeLinks badges={[{href, src, alt}, ...]} /> |
Required imports when using <Tag> or <BadgeLinks> (landing_badges.py adds these in the post stage; in hand-written pages add them yourself):
import { Tag } from "@/components/Tag";
import { BadgeLinks } from "@/components/BadgeLinks";
<Tag variant="..."> accepts: primary, secondary, success, warning, danger, info, light, dark (1:1 with sphinx-design {bdg-*} variants).
Images live in fern/assets/ (shared across all pages) or alongside the MDX file (page-scoped). Reference page-scoped images with relative paths (./image.png), not absolute (/image.png) — Fern's path resolver doesn't normalize root-relative image paths the same way as link targets.
---
title: "<Page Title>" # required — Fern renders this as the page H1
description: "" # required (may be "") — SEO meta description
position: 1 # optional — orders auto-discovered pages within a folder
---
Don't repeat the title as a leading # H1 in the body. Fern already renders title: at the top of the page, and a duplicate creates a double heading. The post-stage remove_duplicate_h1.py strips them when title and H1 match exactly, but it can't catch near-duplicates (e.g. title: "About" vs # About NeMo AutoModel) — keep the body H1-free, or promote the descriptive form to subtitle: if you want both visible.
Use version-agnostic paths — no /latest/, /v0.4/, or /nightly/ prefix:
[Install NeMo AutoModel](/get-started/installation)
[Llama coverage](/model-coverage/large-language-models/llama)
The same MDX backs every version slug; a hard-coded prefix sends readers across versions unintentionally. URL slugs come from explicit slug: overrides in the version YAML (set during the migration so URLs stay short while sidebar titles match the verbose published H1s) — so Install NeMo AutoModel is at /get-started/installation, not /get-started/install-nemo-automodel.
For cross-repo references (yaml configs, Python source), use absolute GitHub URLs:
[mistral4_medpix.yaml](https://github.com/NVIDIA-NeMo/Automodel/blob/main/examples/vlm_finetune/mistral4/mistral4_medpix.yaml)
make docs-check # `fern check` — config + MDX validation
fern check must pass before commit. The dev server's broken-link warnings for version-prefixed routes (e.g. /latest/get-started/installation from MDX that uses /get-started/installation) are false positives — Fern's strict validator doesn't resolve version-agnostic links. The published site renders them correctly. The URLMap-based validate_fern_internal_links.py (under the convert-to-fern toolkit) is authoritative.
To regenerate the autodoc library reference (gitignored under product-docs/):
make docs # runs `fern docs md generate` then `fern docs dev`
fern docs md generate populates product-docs/ from the nemo_automodel package source declared in docs.yml libraries: block. Without this step, a cold fern docs dev fails with Folder not found: ./product-docs/....
| Goal | Command |
|---|---|
Local preview at http://localhost:3002 | make docs |
| Validation only (no server) | make docs-check |
Shared preview URL on *.docs.buildwithfern.com (needs DOCS_FERN_TOKEN) | make docs-preview |
Trigger production publish workflow on origin/main | make docs-publish |
PRs that touch fern/** get an automatic Fern preview URL posted as a 🌿 comment by fern-docs-preview-comment.yml. No manual step.
┌─ fern-docs-ci.yml → fern check (push to pull-request/<n>)
PR (touches fern/) ─┼─ fern-docs-preview-build.yml → upload fern/ artifact (no secrets)
└─ fern-docs-preview-comment.yml → 🌿 preview URL comment
Push to main (touches fern/) → publish-fern-docs.yml → docs.nvidia.com/nemo/automodel
Tag push (docs/v*) → publish-fern-docs.yml → docs.nvidia.com/nemo/automodel
Manual dispatch → publish-fern-docs.yml → docs.nvidia.com/nemo/automodel
The preview-comment + publish jobs require the DOCS_FERN_TOKEN org secret (already wired for build-docs.yml).
When NeMo AutoModel ships a new GA (e.g. v0.5):
cp -r fern/versions/nightly fern/versions/v0.5 — frozen snapshot of the bleeding-edge tree at release.cp fern/versions/nightly.yml fern/versions/v0.5.yml and rewrite ./nightly/ path prefixes to ./v0.5/.fern/versions/latest.yml to point at the new train: cp fern/versions/v0.5.yml fern/versions/latest.yml. (latest is the auto-bumping GA alias.)fern/docs.yml versions:, add a new frozen-pin entry (display-name: "0.5.0 · 26.07", slug: v0.5, availability: stable) and keep the previous pin (v0.4) for permalink stability.fern/versions/nightly/pages/ keeps moving forward as the bleeding-edge tree; the new fern/versions/v0.5/pages/ is the frozen GA snapshot and only changes via deliberate back-port.nightly to availability: stable if and when its content tree gets cut over.docs/v0.5.0 and push to publish.Every commit needs a Signed-off-by: trailer:
git commit -s -m "docs: add fine-tuning guide for Qwen3.6"
If sign-off is missing on a recent commit, amend with git commit --amend -s. PR titles follow Conventional Commits: docs(fern): <short summary>. See AGENTS.md for the full repo commit convention.
| Symptom | Fix |
|---|---|
fern check YAML error | 2-space indent; - page: inside contents:; path: is relative to the version YAML; slug: must not collide with siblings |
| Page 404 in preview | Missing slug: override (default slugifies the long display title) or position: collision in an auto-discovered folder |
Folder not found: ./product-docs/... on fern docs dev | Run make docs once to populate the library reference |
[ERR_PNPM_IGNORED_BUILDS] on first fern docs dev | pnpm 10+ blocks esbuild's postinstall — pnpm config set onlyBuiltDependencies '["esbuild"]' --location global, then rm -rf ~/.fern/app-preview and retry |
| Broken-link warning on version-agnostic path | fern docs broken-links false-positives; URLMap-based validator is authoritative |
JSX expressions must have one parent element | Wrap multi-element JSX in <>...</> or a <div> |
| Old Sphinx URL breaks | Add a redirects: entry in fern/docs.yml; the redirect generator already handles /index.html and .html legacy forms |
| Image not rendering | Use relative path (./image.png) for page-scoped images, not root-relative (/image.png) |
| Sidebar caption looks shortened vs published site | Compare against docs.nvidia.com/nemo/automodel/latest and restore the verbatim title in versions/nightly.yml |
latest.yml or v0.4.yml drift from nightly.yml | Re-sync: `cp fern/versions/nightly.yml fern/versions/latest.yml && sed -i '' 's |
| File | Purpose |
|---|---|
fern/docs.yml | Site config — instances, versions, redirects, libraries, theme |
fern/versions/nightly.yml | Canonical nav tree |
fern/versions/{latest,v0.4}.yml | Aliases — content copies of nightly.yml |
fern/versions/nightly/pages/ | MDX content (130+ pages) |
fern/components/ | BadgeLinks.tsx, Tag.tsx, CustomFooter.tsx |
fern/main.css | Theme overrides — NVIDIA green, badge spacing |
fern/README.md | Human-facing orientation |
fern/Makefile | make docs / docs-check / docs-preview / docs-publish (run from fern/ or via make -C fern) |
.github/workflows/fern-docs-*.yml | CI: check, preview build, preview comment |
.github/workflows/publish-fern-docs.yml | CI: publish to docs.nvidia.com/nemo/automodel |
docs/ | Legacy Sphinx source — read-only reference for fidelity checks |