add option to disable .md output

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to the rt_llms_txt extension will be documented in this file
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Added
+
+- New site setting `llmsTxt.enableMarkdown` (default: enabled) to turn off the `.md` Markdown variant per site. When disabled, `.md` URLs are left untouched by `UrlSuffixMiddleware` (so they 404 normally instead of being rewritten), `ContentFormatMiddleware` refuses to render Markdown as a safety net, and `llms.txt` no longer advertises the Markdown format or lists per-page Markdown links.
+
 ## [1.0.12] - 2026-04-25
 
 ### Fixed

Classes/Middleware/ContentFormatMiddleware.php

@@ -16,6 +16,7 @@
 use TYPO3\CMS\Core\Database\ConnectionPool;
 use TYPO3\CMS\Core\Database\Query\Restriction\DeletedRestriction;
 use TYPO3\CMS\Core\Http\Response;
+use TYPO3\CMS\Core\Site\Entity\Site;
 use TYPO3\CMS\Core\Site\Entity\SiteLanguage;
 
 /**
@@ -49,6 +50,14 @@ public function process(ServerRequestInterface $request, RequestHandlerInterface
             return $handler->handle($request);
         }
 
+        // Safety net: never render Markdown for a site that has it disabled,
+        // regardless of how a request reached this point (defense in depth
+        // alongside UrlSuffixMiddleware, which normally prevents this).
+        $site = $request->getAttribute('site');
+        if ($site instanceof Site && !(bool)$site->getSettings()->get('llmsTxt.enableMarkdown', true)) {
+            return $handler->handle($request);
+        }
+
         // Check API key protection (via ApiKeyAuthenticationTrait)
         $authResponse = $this->checkApiKeyAuth($request);
         if ($authResponse instanceof ResponseInterface) {

Classes/Middleware/UrlSuffixMiddleware.php

@@ -8,6 +8,8 @@
 use Psr\Http\Message\ServerRequestInterface;
 use Psr\Http\Server\MiddlewareInterface;
 use Psr\Http\Server\RequestHandlerInterface;
+use TYPO3\CMS\Core\Routing\SiteMatcher;
+use TYPO3\CMS\Core\Routing\SiteRouteResult;
 
 /**
  * Middleware that detects .md suffix in URLs and rewrites them for routing.
@@ -17,25 +19,46 @@
  * 2. Strip the suffix and set a request attribute for format detection
  * 3. Allow normal TYPO3 routing to find the actual page
  *
+ * If the target site has Markdown output disabled (llmsTxt.enableMarkdown),
+ * the .md suffix is left untouched so normal TYPO3 routing 404s it instead
+ * of exposing any Markdown/content-format handling further down the stack.
+ *
  * Spec-compliant with https://llmstxt.org/
  */
-final class UrlSuffixMiddleware implements MiddlewareInterface
+final readonly class UrlSuffixMiddleware implements MiddlewareInterface
 {
     public const REQUEST_ATTRIBUTE = 'llms_txt_format';
     private const MARKDOWN_SUFFIX = '.md';
     private const INDEX_SUFFIX = '/index.html.md';
 
+    public function __construct(
+        private SiteMatcher $siteMatcher,
+    ) {}
+
     public function process(ServerRequestInterface $request, RequestHandlerInterface $handler): ResponseInterface
     {
         $uri = $request->getUri();
         $path = $uri->getPath();
 
-        // Check for .md suffix
-        if (str_ends_with($path, self::INDEX_SUFFIX)) {
+        $isIndexSuffix = str_ends_with($path, self::INDEX_SUFFIX);
+        $isMarkdownSuffix = !$isIndexSuffix && str_ends_with($path, self::MARKDOWN_SUFFIX);
+
+        if (!$isIndexSuffix && !$isMarkdownSuffix) {
+            return $handler->handle($request);
+        }
+
+        // Site isn't resolved yet at this point in the middleware stack (this
+        // middleware runs before the site resolver on purpose), so the site
+        // has to be matched independently to read its Markdown setting.
+        if (!$this->isMarkdownEnabledForRequest($request)) {
+            return $handler->handle($request);
+        }
+
+        if ($isIndexSuffix) {
             // /page/index.html.md -> /page/
             $newPath = substr($path, 0, -\strlen(self::INDEX_SUFFIX) + 1);
             $request = $this->rewriteRequest($request, $newPath);
-        } elseif (str_ends_with($path, self::MARKDOWN_SUFFIX)) {
+        } else {
             // /page.md -> /page or /page/.md -> /page/
             $newPath = substr($path, 0, -\strlen(self::MARKDOWN_SUFFIX));
             // Handle /page/.md edge case
@@ -52,6 +75,22 @@ public function process(ServerRequestInterface $request, RequestHandlerInterface
         return $handler->handle($request);
     }
 
+    /**
+     * Whether Markdown output is enabled for the site matching this request.
+     *
+     * Defaults to true (enabled) if no site can be matched yet, matching the
+     * setting's own default and preserving prior behaviour for edge cases.
+     */
+    private function isMarkdownEnabledForRequest(ServerRequestInterface $request): bool
+    {
+        $routeResult = $this->siteMatcher->matchRequest($request);
+        if (!$routeResult instanceof SiteRouteResult) {
+            return true;
+        }
+
+        return (bool)$routeResult->getSite()->getSettings()->get('llmsTxt.enableMarkdown', true);
+    }
+
     /**
      * Rewrite the request with new path and set format attribute.
      */

Classes/Service/LlmsTxtGeneratorService.php

@@ -38,6 +38,7 @@ public function getContentForSite(Site $site): string
         $excludePages = $this->parseExcludePages($settings['excludePages'] ?? '');
         $includeHidden = (bool)($settings['includeHidden'] ?? false);
         $intro = trim((string)($settings['intro'] ?? ''));
+        $enableMarkdown = (bool)($settings['enableMarkdown'] ?? true);
 
         $pages = $this->pageTreeService->getPages($site, $defaultLanguage, $excludePages, $includeHidden);
 
@@ -58,7 +59,7 @@ public function getContentForSite(Site $site): string
 
         $apiKey = trim((string)($settings['apiKey'] ?? ''));
 
-        return $this->buildContent($site, $defaultLanguage, $pages, $baseUrl, $intro, $apiKey);
+        return $this->buildContent($site, $defaultLanguage, $pages, $baseUrl, $intro, $apiKey, $enableMarkdown);
     }
 
     /**
@@ -90,6 +91,7 @@ private function buildContent(
         string $baseUrl,
         string $intro,
         string $apiKey,
+        bool $enableMarkdown,
     ): string {
         $lines = [];
 
@@ -115,18 +117,21 @@ private function buildContent(
         $lines[] = '**Generated:** ' . date('Y-m-d H:i:s');
         $lines[] = '';
 
-        // Find an example page (first non-root page for realistic examples)
-        $examplePageUrl = $this->findExamplePageUrl($site, $sortedPages, $language);
-
         // LLM-optimized content access section (spec-compliant with llmstxt.org)
-        $lines[] = '## LLM-Optimized Content Access';
-        $lines[] = '';
-        $lines[] = 'This site provides LLM-friendly Markdown output for all pages:';
-        $lines[] = '';
-        $lines[] = '### Markdown Format';
-        $lines[] = 'Append `.md` to any page URL to get plain Markdown with YAML frontmatter.';
-        $lines[] = '- **Example:** `' . $this->buildMarkdownUrl($examplePageUrl) . '`';
-        $lines[] = '';
+        // Omitted entirely when Markdown output is disabled for this site.
+        if ($enableMarkdown) {
+            // Find an example page (first non-root page for realistic examples)
+            $examplePageUrl = $this->findExamplePageUrl($site, $sortedPages, $language);
+
+            $lines[] = '## LLM-Optimized Content Access';
+            $lines[] = '';
+            $lines[] = 'This site provides LLM-friendly Markdown output for all pages:';
+            $lines[] = '';
+            $lines[] = '### Markdown Format';
+            $lines[] = 'Append `.md` to any page URL to get plain Markdown with YAML frontmatter.';
+            $lines[] = '- **Example:** `' . $this->buildMarkdownUrl($examplePageUrl) . '`';
+            $lines[] = '';
+        }
 
         // Add authentication section if API key is configured
         if ($apiKey !== '') {
@@ -140,7 +145,9 @@ private function buildContent(
             $lines[] = '';
             $lines[] = '**Query Parameter:**';
             $lines[] = '```';
-            $lines[] = $baseUrl . '/page.md?api_key=<your-api-key>';
+            $lines[] = $enableMarkdown
+                ? $baseUrl . '/page.md?api_key=<your-api-key>'
+                : $baseUrl . '/llms.txt?api_key=<your-api-key>';
             $lines[] = '```';
             $lines[] = '';
         }
@@ -178,9 +185,11 @@ private function buildContent(
                 $lines[] = str_repeat('  ', $indent) . '  > ' . str_replace("\n", ' ', $summary);
             }
 
-            // Add format access hints (spec-compliant .md suffix)
-            $mdUrl = $this->buildMarkdownUrl($pageUrl);
-            $lines[] = str_repeat('  ', $indent) . '  [Markdown](' . $mdUrl . ')';
+            // Add format access hints (spec-compliant .md suffix), unless disabled
+            if ($enableMarkdown) {
+                $mdUrl = $this->buildMarkdownUrl($pageUrl);
+                $lines[] = str_repeat('  ', $indent) . '  [Markdown](' . $mdUrl . ')';
+            }
             $lines[] = '';
         }
 

Configuration/Sets/LlmsTxt/settings.definitions.yaml

@@ -27,6 +27,12 @@ settings:
     label: 'Include Hidden Pages'
     description: 'Include hidden pages in llms.txt generation'
     category: llmstxt
+  llmsTxt.enableMarkdown:
+    type: bool
+    default: true
+    label: 'Enable Markdown output'
+    description: 'Serve the .md Markdown variant for pages and reference it from llms.txt. If disabled, .md URLs are left untouched (404) and no Markdown links are listed in llms.txt.'
+    category: llmstxt
   llmsTxt.apiKey:
     type: string
     default: ''

Documentation/Configuration.rst

@@ -71,6 +71,18 @@ you can configure the extension in **Site Management > Settings**.
    If enabled, hidden pages are also included in the llms.txt generation.
    This can be useful for staging environments or preview purposes.
 
+.. _confval-enableMarkdown:
+
+.. confval:: llmsTxt.enableMarkdown
+
+   :type: boolean
+   :Default: true
+
+   If disabled, the ``.md`` Markdown variant is no longer served for any
+   page on this site: ``.md`` URLs are left untouched and resolve as a
+   normal 404 instead of being rewritten, and llms.txt no longer lists a
+   "Markdown Format" section or per-page Markdown links.
+
 .. _confval-apiKey:
 
 .. confval:: llmsTxt.apiKey