Hugo Architecture

Targets Hugo Extended 0.161 (Go-templated static-site generator). Theme styling integrates with ui-ux-architect; Go template syntax overlaps with go-architect; deploy pipelines follow ci-cd-architect. Concrete skeletons in RECIPES.md; pinned versions in STACK.md.

1. Project layout & content organization

• Standard top-level folders — content/, layouts/, assets/, static/, data/, i18n/, archetypes/, themes/ (if not module-mounted), hugo.toml. Skeleton in RECIPES § Project tree.
• content/ mirrors the URL structure. Section folders (content/posts/, content/docs/) become URL prefixes; taxonomies are inferred from front matter, not folder names.
• assets/ for processed files; static/ for pass-through. Anything that needs fingerprinting, minification, transpilation, or image processing belongs in assets/ and goes through Hugo Pipes. Truly static files (robots.txt, favicon.ico, prebuilt PDFs) go in static/.
• data/ for structured site data — JSON/YAML/TOML files queryable via site.Data.<file>. Use for author lists, sponsor logos, redirect maps; do not use for content (that belongs in content/).
• archetypes/ define hugo new templates — one per content section, with sensible front-matter defaults.
• One repository per site by default. Multi-site monorepos are an exception; reach for them only when ownership and deploy targets align.

2. Front matter conventions

• TOML front matter is the default (+++ delimiters). Matches hugo.toml config syntax — one parser to learn. YAML is acceptable for theme authors who must support broader ecosystems; pick one per repo and don't mix.
• Required fields on every page — title, date, draft (default false once published). Drafts are excluded from production builds.
• Taxonomies are arrays — tags = ["x", "y"], never comma-separated strings. Taxonomies auto-generate listing pages.
• slug only when the title is unstable. Otherwise let Hugo derive from the filename — stable URLs survive title edits.
• weight for manual ordering — lower = earlier. Reserve for navigation menus and curated lists; chronological content uses date.
• Custom params under [params] — never at the top level. params is the supported namespace for site-specific extensions; top-level keys collide with future Hugo additions.

3. Template hierarchy

Hugo's lookup order resolves templates from most-specific to most-generic. Internalize the order; don't memorize it — the Hugo template lookup docs are the source of truth.

• baseof.html is the single shell template. Every other template extends it via {{ define "main" }}.
• single.html renders one page; list.html renders section/taxonomy listings; home.html is the site root.
• partials/ are reusable fragments — header, footer, SEO meta. Pass an explicit context; never rely on the global scope.
• shortcodes/ are content-callable partials — invoke from Markdown with {{< name >}}. Use for figures, callouts, embeds; do not use to inject styling.
• Type/section overrides — layouts/posts/single.html beats layouts/_default/single.html. The _default/ folder is the fallback, not the convention.

Skeletons in RECIPES § Template hierarchy.

4. Hugo Modules over git submodules

• Themes and shared layouts ship as Hugo Modules — Go-module-backed, versioned via SemVer tags. hugo mod get resolves; go.mod records.
• Why not git submodules? Submodules pin to commits with no version semantics, require git submodule update --init after every clone, and break on theme repo reorganizations. Modules give SemVer + automatic dependency resolution.
• hugo.toml [module] block declares imports, mounts, and replacements. Mount overrides let you patch a single template without forking the theme.
• Vendor for reproducibility — hugo mod vendor writes _vendor/; commit it for hermetic builds (mirrors Go's vendor/ discipline per go-architect).

Skeleton in RECIPES § Hugo Module setup.

5. Page Bundles over flat content

• Page Bundle = index.md + co-located assets in a folder. content/posts/launch-day/index.md plus cover.jpg, diagram.svg in the same folder.
• Two bundle types:
  • Leaf bundle (index.md) — a single page; resources are bundle-local.
  • Branch bundle (_index.md) — a section page; child pages are independent.
• Why bundles? Page resources (resources.Get, .Resources.GetMatch) are scoped to the bundle, image processing works on co-located files, and content + assets move together.
• Flat content/posts/foo.md is acceptable for text-only posts with no images. Reach for bundles the moment you have a cover image or inline diagram.

6. Asset pipeline (Hugo Pipes)

Hugo Pipes is the built-in asset pipeline — no Webpack, no Vite. Extended edition required for Sass/SCSS.

• Source files in assets/ — invoke via resources.Get "css/app.scss".
• Standard chain — toCSS (or js.Build) → postCSS (optional, for Tailwind/autoprefixer) → minify → fingerprint → render <link> / <script> with Permalink + Data.Integrity (SRI).
• Fingerprinting is mandatory in production — long-cache headers + immutable URLs. Build with --minify and rely on the fingerprint for cache busting.
• Image processing — .Resize, .Fit, .Fill, .Filter. Pair with srcset for responsive images. WebP/AVIF output via format conversion. Use q= for JPEG quality; don't blow the byte budget.
• PostCSS lives outside Hugo — postcss.config.js + package.json. Hugo invokes the binary; keep the toolchain pinned via repo-tooling-architect.

Skeleton in RECIPES § Asset pipeline chain.

7. Performance budget

• Build time target — under 10s for sites under 1k pages; under 60s for sites under 10k pages. Beyond that, profile (hugo --templateMetrics) and audit the slowest partial/shortcode.
• Per-page weight — under 100 KB transferred (HTML + CSS + JS + critical fonts) for content pages. Images load lazily via loading="lazy" and srcset.
• No JS by default. Add JS only where it earns its place (search, comments, interactive widgets). Hugo's strength is shipping HTML; don't undermine it.
• Tailwind via PostCSS with content globbing — production builds purge unused classes. Without purging, Tailwind ships ~3 MB CSS.
• Critical CSS inline for above-the-fold when Lighthouse flags it; fingerprinted external CSS for the rest.

8. i18n & multilingual

• [languages] block in hugo.toml — one entry per language, with weight, languageName, contentDir, languageDirection.
• Translation strategies — by filename (post.en.md + post.es.md) or by content directory (content/en/ + content/es/). Pick one per site; filename mode is simpler, directory mode scales better past three languages.
• i18n/<lang>.toml for UI strings — invoke via {{ i18n "key" }}. Don't hardcode strings in templates.
• Translation linking — Hugo auto-links translations by translationKey (front matter) when filenames diverge.
• Default language has no URL prefix unless defaultContentLanguageInSubdir = true. Decide early — changing later breaks every existing URL.

9. Render hooks & Markdown extensions

• Goldmark is the Markdown parser. Render hooks override individual element rendering — render-link.html, render-image.html, render-codeblock-<lang>.html, render-heading.html.
• Use render hooks for — aut