Add built-in RSS feed support

docs/site/concepts/routing.md

@@ -24,13 +24,16 @@ docs/site/
 - skill homepage -> `/skill-name/` using `SKILL.md` when neither `index.md` nor `README.md` exists
 - `guides/getting-started.md` -> `/guides/getting-started.md`, `/guides/getting-started.html`, `/guides/getting-started`
 - sitemap -> `/sitemap.xml`
+- RSS feed -> `/feed.xml` when `siteUrl` is configured and RSS is not disabled
 
 If a directory has no `index.md`, the current runtime can still render a minimal fallback listing for browsing.
 
 The content tree may also include directory symlinks. `mdorigin` follows them in local preview and build-time processing, while keeping the published URL based on the visible path inside the content root.
 
 `/sitemap.xml` emits canonical HTML URLs, not `.md` source URLs. It requires `siteUrl` so the sitemap can use absolute locations.
 
+`/feed.xml` also requires `siteUrl`, because feed items use absolute canonical URLs.
+
 Rendered HTML also exposes the source markdown path with:
 
 ```html
@@ -39,6 +42,12 @@ Rendered HTML also exposes the source markdown path with:
 
 This is a lightweight interoperability hint for agents and tools that want to discover the raw markdown source from the human HTML page.
 
+When RSS is enabled, rendered HTML also exposes feed autodiscovery:
+
+```html
+<link rel="alternate" type="application/rss+xml" href="https://example.com/feed.xml">
+```
+
 ## Canonical markdown paths
 
 Directory homepages support `index.md`, `README.md`, and `SKILL.md`, but only one can act as the effective source file for a given directory.

docs/site/guides/getting-started.md

@@ -185,6 +185,31 @@ The built-in presentation is now fixed to the default atlas baseline. Configure
 }
 ```
 
+Once `siteUrl` is set, `mdorigin` also enables:
+
+- `/sitemap.xml`
+- `/feed.xml`
+
+If you want to turn RSS off or override feed metadata, add:
+
+```json
+{
+  "rss": {
+    "title": "Example Feed",
+    "description": "Latest updates from Example",
+    "maxItems": 20
+  }
+}
+```
+
+Or disable it entirely:
+
+```json
+{
+  "rss": false
+}
+```
+
 If a page contains a managed index block, the default renderer automatically presents it as a structured listing. `mdorigin` no longer exposes built-in theme/template variants as product configuration.
 
 If you want to start using code-based extensions now, switch from JSON config to `mdorigin.config.ts` and export a config object with `plugins`.

docs/site/reference/configuration.md

@@ -118,6 +118,7 @@ The design boundary is:
 
 - `siteUrl` sets the canonical site origin and is used for canonical links in rendered HTML.
 - `siteUrl` also enables `/sitemap.xml`, which emits absolute canonical URLs.
+- `siteUrl` also enables `/feed.xml` by default unless RSS is explicitly disabled.
 - `favicon` adds a standard favicon link tag.
 - `socialImage` emits absolute `og:image` and `twitter:image` metadata when `siteUrl` is set.
 - `logo` renders a small site logo in the header.
@@ -136,6 +137,37 @@ Example:
 }
 ```
 
+## RSS
+
+`mdorigin` can emit a built-in RSS feed at `/feed.xml`.
+
+Rules:
+
+- if `siteUrl` is set, RSS is enabled by default
+- set `"rss": false` to disable the feed
+- the feed emits dated post content, not every page in the tree
+- rendered HTML adds an RSS autodiscovery `<link rel="alternate" ...>` when the feed is enabled
+
+Optional overrides:
+
+```json
+{
+  "rss": {
+    "title": "Example Feed",
+    "description": "Latest updates from Example",
+    "author": "editor@example.com",
+    "maxItems": 20
+  }
+}
+```
+
+Supported fields:
+
+- `rss.title`
+- `rss.description`
+- `rss.author`
+- `rss.maxItems`
+
 ## Footer
 
 `mdorigin` supports a small set of explicit footer settings:

skills/mdorigin/SKILL.md

@@ -29,6 +29,7 @@ npm install --save-dev mdorigin
 - Cloudflare Worker bundle output with `mdorigin build cloudflare`
 - external binary deployment flow for Cloudflare Assets + R2
 - markdown and HTML route behavior, including `Accept: text/markdown`
+- built-in `/sitemap.xml` and `/feed.xml` when `siteUrl` is configured
 
 ## Quick commands
 

src/core/request-handler.test.ts

@@ -446,6 +446,113 @@ test('handleSiteRequest returns an error for sitemap.xml when siteUrl is missing
   assert.match(String(response.body), /siteUrl/);
 });
 
+test('handleSiteRequest renders feed.xml for dated posts and adds autodiscovery link', async () => {
+  const store = new MemoryContentStore([
+    {
+      path: 'README.md',
+      kind: 'text',
+      mediaType: 'text/markdown; charset=utf-8',
+      text: ['---', 'title: Home', 'summary: Site summary', '---', '', '# Home'].join('\n'),
+    },
+    {
+      path: 'posts/new.md',
+      kind: 'text',
+      mediaType: 'text/markdown; charset=utf-8',
+      text: [
+        '---',
+        'title: New Post',
+        'date: 2026-03-22',
+        'summary: Fresh summary',
+        '---',
+        '',
+        '# New Post',
+      ].join('\n'),
+    },
+    {
+      path: 'posts/old.md',
+      kind: 'text',
+      mediaType: 'text/markdown; charset=utf-8',
+      text: [
+        '---',
+        'title: Old Post',
+        'date: 2026-03-20',
+        '---',
+        '',
+        'First paragraph excerpt.',
+      ].join('\n'),
+    },
+    {
+      path: 'guides/page.md',
+      kind: 'text',
+      mediaType: 'text/markdown; charset=utf-8',
+      text: ['---', 'title: Guide', 'date: 2026-03-21', 'type: page', '---', '', '# Guide'].join('\n'),
+    },
+    {
+      path: 'draft.md',
+      kind: 'text',
+      mediaType: 'text/markdown; charset=utf-8',
+      text: ['---', 'title: Draft', 'date: 2026-03-23', 'draft: true', '---', '', '# Draft'].join('\n'),
+    },
+  ]);
+
+  const siteConfig = {
+    ...TEST_SITE_CONFIG,
+    siteUrl: 'https://example.com',
+    siteDescription: 'Configured site description',
+  };
+
+  const feedResponse = await handleSiteRequest(store, '/feed.xml', {
+    draftMode: 'exclude',
+    siteConfig,
+  });
+
+  assert.equal(feedResponse.status, 200);
+  assert.equal(feedResponse.headers['content-type'], 'application/rss+xml; charset=utf-8');
+  const feedBody = String(feedResponse.body);
+  assert.match(feedBody, /<title>Test Site<\/title>/);
+  assert.match(feedBody, /<link>https:\/\/example\.com<\/link>/);
+  assert.match(feedBody, /<atom:link href="https:\/\/example\.com\/feed\.xml"/);
+  assert.match(feedBody, /<title>New Post<\/title>[\s\S]*<title>Old Post<\/title>/);
+  assert.match(feedBody, /<guid isPermaLink="true">https:\/\/example\.com\/posts\/new<\/guid>/);
+  assert.match(feedBody, /<description>Fresh summary<\/description>/);
+  assert.match(feedBody, /<description>First paragraph excerpt\.<\/description>/);
+  assert.doesNotMatch(feedBody, /Guide/);
+  assert.doesNotMatch(feedBody, /Draft/);
+
+  const htmlResponse = await handleSiteRequest(store, '/posts/new.html', {
+    draftMode: 'exclude',
+    siteConfig,
+  });
+  assert.equal(htmlResponse.status, 200);
+  assert.match(
+    String(htmlResponse.body),
+    /<link rel="alternate" type="application\/rss\+xml" title="Test Site" href="https:\/\/example\.com\/feed\.xml">/,
+  );
+});
+
+test('handleSiteRequest returns 404 for feed.xml when siteUrl is missing or rss is disabled', async () => {
+  const store = new MemoryContentStore([]);
+
+  const missingSiteUrl = await handleSiteRequest(store, '/feed.xml', {
+    draftMode: 'exclude',
+    siteConfig: TEST_SITE_CONFIG,
+  });
+  assert.equal(missingSiteUrl.status, 404);
+
+  const disabledRss = await handleSiteRequest(store, '/feed.xml', {
+    draftMode: 'exclude',
+    siteConfig: {
+      ...TEST_SITE_CONFIG,
+      siteUrl: 'https://example.com',
+      rss: {
+        enabled: false,
+        maxItems: 20,
+      },
+    },
+  });
+  assert.equal(disabledRss.status, 404);
+});
+
 test('handleSiteRequest serves OpenAPI schema for search', async () => {
   const response = await handleSiteRequest(
     new MemoryContentStore([]),