Add docs article updated dates and Atom feed

.gitignore

@@ -19,6 +19,7 @@ site/public/api-meta/
 site/public/api-catalog.json
 site/public/docs-markdown/
 site/public/sitemap.xml
+site/public/feed.xml
 
 ###############
 # OS / IDE

site/app/composables/usePageSeo.ts

@@ -12,6 +12,8 @@ type PageSeoOptions = {
   title?: MaybeRefOrGetter<string | undefined>
   description?: MaybeRefOrGetter<string | undefined>
   image?: MaybeRefOrGetter<string | undefined>
+  /** Article last-updated day as YYYY-MM-DD (adds Open Graph modified_time). */
+  modifiedTime?: MaybeRefOrGetter<string | undefined>
 }
 
 export function usePageSeo(options: PageSeoOptions = {}) {
@@ -22,23 +24,38 @@ export function usePageSeo(options: PageSeoOptions = {}) {
   const description = computed(() => toValue(options.description) ?? DEFAULT_DESCRIPTION)
   const image = computed(() => `${siteUrl}${toValue(options.image) ?? DEFAULT_OG_IMAGE}`)
   const url = computed(() => `${siteUrl}${route.path}`)
+  const modifiedTime = computed(() => {
+    const day = toValue(options.modifiedTime)
+    return day ? `${day}T00:00:00.000Z` : undefined
+  })
 
   useHead({
     title,
-    meta: computed(() => [
-      { name: 'description', content: description.value, tagPriority: seoTagPriority },
-      { property: 'og:site_name', content: 'AutoFixture', tagPriority: seoTagPriority },
-      { property: 'og:type', content: 'website', tagPriority: seoTagPriority },
-      { property: 'og:title', content: title.value, tagPriority: seoTagPriority },
-      { property: 'og:description', content: description.value, tagPriority: seoTagPriority },
-      { property: 'og:image', content: image.value, tagPriority: seoTagPriority },
-      { property: 'og:image:width', content: OG_IMAGE_WIDTH, tagPriority: seoTagPriority },
-      { property: 'og:image:height', content: OG_IMAGE_HEIGHT, tagPriority: seoTagPriority },
-      { property: 'og:url', content: url.value, tagPriority: seoTagPriority },
-      { name: 'twitter:card', content: 'summary_large_image', tagPriority: seoTagPriority },
-      { name: 'twitter:title', content: title.value, tagPriority: seoTagPriority },
-      { name: 'twitter:description', content: description.value, tagPriority: seoTagPriority },
-      { name: 'twitter:image', content: image.value, tagPriority: seoTagPriority },
-    ]),
+    meta: computed(() => {
+      const tags = [
+        { name: 'description', content: description.value, tagPriority: seoTagPriority },
+        { property: 'og:site_name', content: 'AutoFixture', tagPriority: seoTagPriority },
+        { property: 'og:type', content: 'website', tagPriority: seoTagPriority },
+        { property: 'og:title', content: title.value, tagPriority: seoTagPriority },
+        { property: 'og:description', content: description.value, tagPriority: seoTagPriority },
+        { property: 'og:image', content: image.value, tagPriority: seoTagPriority },
+        { property: 'og:image:width', content: OG_IMAGE_WIDTH, tagPriority: seoTagPriority },
+        { property: 'og:image:height', content: OG_IMAGE_HEIGHT, tagPriority: seoTagPriority },
+        { property: 'og:url', content: url.value, tagPriority: seoTagPriority },
+        { name: 'twitter:card', content: 'summary_large_image', tagPriority: seoTagPriority },
+        { name: 'twitter:title', content: title.value, tagPriority: seoTagPriority },
+        { name: 'twitter:description', content: description.value, tagPriority: seoTagPriority },
+        { name: 'twitter:image', content: image.value, tagPriority: seoTagPriority },
+      ]
+
+      if (modifiedTime.value) {
+        tags.push(
+          { property: 'article:modified_time', content: modifiedTime.value, tagPriority: seoTagPriority },
+          { property: 'og:updated_time', content: modifiedTime.value, tagPriority: seoTagPriority },
+        )
+      }
+
+      return tags
+    }),
   })
 }

site/app/pages/docs/[...slug].vue

@@ -1,4 +1,6 @@
 <script setup lang="ts">
+import { formatDocsUpdatedDate } from '~/utils/formatDocsUpdatedDate'
+
 definePageMeta({
   layout: 'docs',
 })
@@ -20,9 +22,12 @@ const { data: surround } = await useAsyncData(
   () => queryCollectionItemSurroundings('docs', docsPath.value),
 )
 
+const updated = computed(() => formatDocsUpdatedDate(page.value?.updated))
+
 usePageSeo({
   title: () => page.value?.title,
   description: () => page.value?.description,
+  modifiedTime: () => updated.value?.iso,
 })
 
 const tocLinks = computed(() => page.value?.body?.toc?.links ?? [])
@@ -33,7 +38,15 @@ const tocLinks = computed(() => page.value?.body?.toc?.links ?? [])
     <UPageHeader
       :title="page.title"
       :description="page.description"
-    />
+    >
+      <p
+        v-if="updated"
+        class="mt-3 text-sm text-muted"
+      >
+        Updated
+        <time :datetime="updated.iso">{{ updated.label }}</time>
+      </p>
+    </UPageHeader>
 
     <UPageBody>
       <ContentRenderer

site/app/utils/formatDocsUpdatedDate.ts

@@ -0,0 +1,69 @@
+/**
+ * Normalize and format docs frontmatter `updated` (YYYY-MM-DD or Date).
+ */
+
+export type DocsUpdatedDate = {
+  /** Calendar date as YYYY-MM-DD (UTC). */
+  iso: string
+  /** Human-readable label, e.g. "March 15, 2026". */
+  label: string
+}
+
+function pad2(n: number): string {
+  return String(n).padStart(2, '0')
+}
+
+/** Return YYYY-MM-DD for a valid calendar date, or undefined. */
+export function toDocsUpdatedIso(value: unknown): string | undefined {
+  if (value === undefined || value === null || value === '') {
+    return undefined
+  }
+
+  if (value instanceof Date && !Number.isNaN(value.getTime())) {
+    return `${value.getUTCFullYear()}-${pad2(value.getUTCMonth() + 1)}-${pad2(value.getUTCDate())}`
+  }
+
+  if (typeof value === 'string') {
+    const trimmed = value.trim()
+    const match = /^(\d{4})-(\d{2})-(\d{2})$/.exec(trimmed)
+    if (!match) {
+      return undefined
+    }
+    const year = Number(match[1])
+    const month = Number(match[2])
+    const day = Number(match[3])
+    const probe = new Date(Date.UTC(year, month - 1, day))
+    if (
+      probe.getUTCFullYear() !== year
+      || probe.getUTCMonth() !== month - 1
+      || probe.getUTCDate() !== day
+    ) {
+      return undefined
+    }
+    return trimmed
+  }
+
+  return undefined
+}
+
+/**
+ * Format an `updated` value for display and `<time datetime>`.
+ * Uses the en-US long date style (month day, year).
+ */
+export function formatDocsUpdatedDate(value: unknown): DocsUpdatedDate | undefined {
+  const iso = toDocsUpdatedIso(value)
+  if (!iso) {
+    return undefined
+  }
+
+  const [year, month, day] = iso.split('-').map(Number)
+  const date = new Date(Date.UTC(year!, month! - 1, day!))
+  const label = new Intl.DateTimeFormat('en-US', {
+    year: 'numeric',
+    month: 'long',
+    day: 'numeric',
+    timeZone: 'UTC',
+  }).format(date)
+
+  return { iso, label }
+}

site/content.config.ts

@@ -17,6 +17,11 @@ export default defineContentConfig({
       },
       schema: z.object({
         description: z.string().optional(),
+        /**
+         * Last meaningful content update (calendar day).
+         * Prefer `YYYY-MM-DD` in frontmatter; YAML dates are also accepted.
+         */
+        updated: z.union([z.string(), z.date()]).optional(),
         /** Sidebar badge — string shortcut (`New`, `Updated`, `Preview`) or Nuxt UI BadgeProps. */
         badge: z.union([z.string(), z.number(), badgeObjectSchema]).optional(),
       }),

site/content/docs/5.integrations/10.tunit.md

@@ -1,6 +1,7 @@
 ---
 title: TUnit
 description: Use AutoDataSource, AutoArguments, and parameter attributes with TUnit test projects.
+updated: 2026-09-08
 badge:
   label: Preview
   color: warning

site/nuxt.config.ts

@@ -77,6 +77,13 @@ export default defineNuxtConfig({
           type: 'image/svg+xml',
           href: '/favicon.svg?v=2',
         },
+        {
+          key: 'docs-atom-feed',
+          rel: 'alternate',
+          type: 'application/atom+xml',
+          title: 'AutoFixture documentation',
+          href: '/feed.xml',
+        },
       ],
     },
   },

site/public/llms.txt

@@ -64,7 +64,8 @@ Slugs and version segments are lowercase. Package ids match the catalog (autofix
 - https://autofixture.com/api-meta/routes.json — all API HTML routes
 - https://autofixture.com/api-meta/{packageId}/{versionSegment}/toc.json — package TOC
 - https://autofixture.com/api-meta/{packageId}/{versionSegment}/search.json — searchable API snippets
-- https://autofixture.com/sitemap.xml — HTML and markdown URLs
+- https://autofixture.com/sitemap.xml — HTML and markdown URLs (`lastmod` when guides set `updated`)
+- https://autofixture.com/feed.xml — Atom feed of recently updated guides
 
 ## Optional
 

site/readme.md

@@ -28,7 +28,8 @@ just site-generate   # runs prepare-agent-assets, then nuxt generate
 | `/api-markdown/**` | Raw API markdown (generated; not committed) |
 | `/llms.txt` | Agent discovery index |
 | `/robots.txt` | Crawler rules + sitemap pointer |
-| `/sitemap.xml` | Generated URL list (guides, docs-markdown, API) |
+| `/sitemap.xml` | Generated URL list (guides, docs-markdown, API); includes `lastmod` when set |
+| `/feed.xml` | Atom feed of guides that declare `updated` |
 
 API markdown is generated into `public/api-markdown` (not Nuxt Content). On API pages, the header shows the package and version from the API catalog.
 
@@ -37,13 +38,30 @@ API markdown is generated into `public/api-markdown` (not Nuxt Content). On API
 `scripts/prepare-agent-assets.mjs` (also `npm run prepare-agent-assets` / `pregenerate`):
 
 1. Mirrors `content/docs/**/*.md` → `public/docs-markdown/` with Nuxt-style paths (numeric prefixes stripped).
-2. Writes `public/sitemap.xml` from those guides plus `public/api-meta/routes.json` when present.
+2. Writes `public/sitemap.xml` from those guides plus `public/api-meta/routes.json` when present (`lastmod` from frontmatter `updated`).
+3. Writes `public/feed.xml` (Atom) for guides that set `updated`.
 
 Committed: `public/llms.txt`, `public/robots.txt`.
-Generated (gitignored): `public/docs-markdown/`, `public/sitemap.xml`.
+Generated (gitignored): `public/docs-markdown/`, `public/sitemap.xml`, `public/feed.xml`.
 
 Keep `llms.txt` in sync when you add major guide sections.
 
+## Article freshness (`updated`)
+
+Set `updated` in page frontmatter to a calendar day (`YYYY-MM-DD`). The docs page shows an "Updated …" line under the header, Open Graph gets `article:modified_time`, the sitemap gets `lastmod`, and the Atom feed includes the article.
+
+```yaml
+---
+title: Build DSL
+description: Use Build, With, Without, and OmitAutoProperties…
+updated: 2026-09-08
+---
+```
+
+Bump `updated` when you make a meaningful content change. Omit it when the day is unknown — the UI simply hides the line.
+
+Sidebar `badge: Updated` stays optional and explicit; it is not derived from `updated`.
+
 ## Sidebar badges
 
 Set an optional `badge` in page frontmatter to show a label next to the article in the docs sidebar (desktop and mobile). Badges are explicit — nothing is inferred from dates or git.