diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 8f16da9eb8..f28ba79d88 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -230,6 +230,18 @@ jobs:
                     assert_header "http://localhost:8080/cli/llms.txt" "Content-Type" "text/markdown"
                     assert_header "http://localhost:8080/cli/llms-full.txt" "Content-Type" "text/markdown"
 
+                    echo "🧪 Checking doubled section prefix redirect..."
+                    # Regression tests for the llms-txt plugin workaround in nginx.conf.
+                    # Doubled prefixes redirect to the canonical URL and keep the query
+                    # string. Remove together with the workaround.
+                    assert_status "http://localhost:8080/sdk/js/sdk/js/docs/introduction/quick-start" "301"
+                    assert_header "http://localhost:8080/sdk/js/sdk/js/docs/introduction/quick-start" "Location" "^Location: http://[^/]*/sdk/js/docs/introduction/quick-start$"
+                    assert_header "http://localhost:8080/sdk/js/sdk/js/docs/introduction/quick-start.md?x=1" "Location" "^Location: http://[^/]*/sdk/js/docs/introduction/quick-start[.]md[?]x=1$"
+                    assert_header "http://localhost:8080/sdk/python/sdk/python/docs/changelog" "Location" "^Location: http://[^/]*/sdk/python/docs/changelog$"
+                    assert_header "http://localhost:8080/api/client/js/api/client/js/docs/changelog" "Location" "^Location: http://[^/]*/api/client/js/docs/changelog$"
+                    assert_header "http://localhost:8080/api/client/python/api/client/python/docs/changelog" "Location" "^Location: http://[^/]*/api/client/python/docs/changelog$"
+                    assert_header "http://localhost:8080/cli/cli/docs/changelog" "Location" "^Location: http://[^/]*/cli/docs/changelog$"
+
                     echo "✅ All Nginx header checks passed."
 
             -   name: Verify per-page .md navigation headers
diff --git a/nginx.conf b/nginx.conf
index 1996d680fa..857dea168f 100644
--- a/nginx.conf
+++ b/nginx.conf
@@ -63,6 +63,17 @@ server {
         rewrite ^(.+)/$ $1$is_args$args? redirect;
     }
 
+    # @signalwire/docusaurus-plugin-llms-txt 1.2.2 repeats the section prefix in the
+    # .md files and llms*.txt it generates for sites served under a sub-path, so links
+    # such as /sdk/python/sdk/python/docs/... 404. The five sub-sites still pin ^1.2.2.
+    # This redirect makes those links resolve in one hop. Keep it after the sub-sites
+    # stop generating them: the doubled URLs stay in search indexes and agent caches.
+    # It only collapses a repeated same-section prefix. The plugin also prefixes
+    # cross-section links (/sdk/js/cli/docs/...), which this cannot detect.
+    location ~ "^/(sdk/js|sdk/python|api/client/js|api/client/python|cli)/\1(/.*)?$" {
+        return 301 /$1$2$is_args$args;
+    }
+
     location / {
         set $rewrite_condition "$serve_markdown$has_no_extension";
         set $proxy_path $request_uri;
diff --git a/scripts/checkLlmsSize.mjs b/scripts/checkLlmsSize.mjs
index fad4bc3f03..1ff1c8ef97 100644
--- a/scripts/checkLlmsSize.mjs
+++ b/scripts/checkLlmsSize.mjs
@@ -27,6 +27,20 @@ if (llmsChars === null || llmsFullChars === null) {
     process.exit(1);
 }
 
+// Guards the substitution in joinLlmsFiles.mjs. The sub-sites generate links with their
+// section prefix repeated; if the substitution stops matching, the joined files silently
+// fill up with URLs that only resolve through the redirect in nginx.conf.
+const DOUBLED_SECTION_PREFIX =
+    /https:\/\/docs\.apify\.com\/(sdk\/js|sdk\/python|api\/client\/js|api\/client\/python|cli)\/\1\//g;
+
+for (const filePath of [llmsPath, llmsFullPath]) {
+    const matches = (await fs.readFile(filePath, 'utf8')).match(DOUBLED_SECTION_PREFIX);
+    if (matches) {
+        console.error(`\nERROR: ${filePath} has ${matches.length} links with a doubled section prefix`);
+        process.exitCode = 1;
+    }
+}
+
 console.log(`llms.txt:      ${llmsChars.toLocaleString()} characters`);
 console.log(`llms-full.txt: ${llmsFullChars.toLocaleString()} characters`);
 
diff --git a/scripts/joinLlmsFiles.mjs b/scripts/joinLlmsFiles.mjs
index 34130cb539..f43699c2a6 100644
--- a/scripts/joinLlmsFiles.mjs
+++ b/scripts/joinLlmsFiles.mjs
@@ -253,9 +253,18 @@ async function joinFiles() {
     console.log('Wrote llms-full.txt to build/');
 }
 
+// WORKAROUND: @signalwire/docusaurus-plugin-llms-txt 1.2.2 doubles the section prefix in
+// cross-links on sites served under a sub-path, so the SDK/client/CLI sections we fetch above
+// arrive with links such as /sdk/python/sdk/python/docs/... Fixed upstream in 2.0.0-alpha.6;
+// those sites still pin ^1.2.2. Remove once they stop generating the doubled prefix.
+const DOUBLED_SECTION_PREFIX =
+    /(https:\/\/docs\.apify\.com\/(sdk\/js|sdk\/python|api\/client\/js|api\/client\/python|cli))\/\2\//g;
+
 async function sanitizeFile(filePath) {
     const content = await fs.readFile(filePath, 'utf8');
-    const sanitizedContent = content.replace(/<[^>]*>/g, ''); // Remove HTML tags
+    const sanitizedContent = content
+        .replace(/<[^>]*>/g, '') // Remove HTML tags
+        .replace(DOUBLED_SECTION_PREFIX, '$1/');
     await fs.writeFile(filePath, sanitizedContent, 'utf8');
     console.log(`Sanitized ${filePath}`);
 }