diff --git a/package.json b/package.json
index b4ff610d..c0aae49d 100644
--- a/package.json
+++ b/package.json
@@ -4,8 +4,8 @@
   "description": "",
   "main": "index.js",
   "scripts": {
-    "postinstall": "node scripts/patch-lightningcss.mjs && node scripts/patch-endpoint-media-scope.mjs && node scripts/patch-endpoint-media-sharp-runtime.mjs && node scripts/patch-frontend-sharp-runtime.mjs && node scripts/patch-endpoint-files-upload-route.mjs && node scripts/patch-endpoint-files-upload-locales.mjs && node scripts/patch-endpoint-activitypub-locales.mjs && node scripts/patch-endpoint-activitypub-docloader-loglevel.mjs && node scripts/patch-endpoint-homepage-locales.mjs && node scripts/patch-federation-unlisted-guards.mjs && node scripts/patch-endpoint-micropub-where-note-visibility.mjs && node scripts/patch-frontend-serviceworker-file.mjs && node scripts/patch-conversations-collection-guards.mjs && node scripts/patch-conversations-mastodon-disconnect.mjs && node scripts/patch-indiekit-routes-rate-limits.mjs && node scripts/patch-indiekit-error-production-stack.mjs && node scripts/patch-indieauth-devmode-guard.mjs && node scripts/patch-listening-endpoint-runtime-guards.mjs",
-    "serve": "export NODE_ENV=${NODE_ENV:-production} INDIEKIT_DEBUG=${INDIEKIT_DEBUG:-0} && node scripts/preflight-production-security.mjs && node scripts/preflight-mongo-connection.mjs && node scripts/preflight-activitypub-rsa-key.mjs && node scripts/preflight-activitypub-profile-urls.mjs && node scripts/patch-lightningcss.mjs && node scripts/patch-endpoint-media-scope.mjs && node scripts/patch-endpoint-media-sharp-runtime.mjs && node scripts/patch-frontend-sharp-runtime.mjs && node scripts/patch-endpoint-files-upload-route.mjs && node scripts/patch-endpoint-files-upload-locales.mjs && node scripts/patch-endpoint-activitypub-locales.mjs && node scripts/patch-endpoint-activitypub-docloader-loglevel.mjs && node scripts/patch-endpoint-homepage-locales.mjs && node scripts/patch-federation-unlisted-guards.mjs && node scripts/patch-endpoint-micropub-where-note-visibility.mjs && node scripts/patch-frontend-serviceworker-file.mjs && node scripts/patch-conversations-collection-guards.mjs && node scripts/patch-conversations-mastodon-disconnect.mjs && node scripts/patch-indiekit-routes-rate-limits.mjs && node scripts/patch-indiekit-error-production-stack.mjs && node scripts/patch-indieauth-devmode-guard.mjs && node scripts/patch-listening-endpoint-runtime-guards.mjs && node node_modules/@indiekit/indiekit/bin/cli.js serve --config indiekit.config.mjs",
+    "postinstall": "node scripts/patch-lightningcss.mjs && node scripts/patch-endpoint-media-scope.mjs && node scripts/patch-endpoint-media-sharp-runtime.mjs && node scripts/patch-frontend-sharp-runtime.mjs && node scripts/patch-endpoint-files-upload-route.mjs && node scripts/patch-endpoint-files-upload-locales.mjs && node scripts/patch-endpoint-activitypub-locales.mjs && node scripts/patch-endpoint-activitypub-docloader-loglevel.mjs && node scripts/patch-endpoint-homepage-locales.mjs && node scripts/patch-federation-unlisted-guards.mjs && node scripts/patch-endpoint-micropub-where-note-visibility.mjs && node scripts/patch-preset-eleventy-ai-frontmatter.mjs && node scripts/patch-frontend-serviceworker-file.mjs && node scripts/patch-conversations-collection-guards.mjs && node scripts/patch-conversations-mastodon-disconnect.mjs && node scripts/patch-indiekit-routes-rate-limits.mjs && node scripts/patch-indiekit-error-production-stack.mjs && node scripts/patch-indieauth-devmode-guard.mjs && node scripts/patch-listening-endpoint-runtime-guards.mjs",
+    "serve": "export NODE_ENV=${NODE_ENV:-production} INDIEKIT_DEBUG=${INDIEKIT_DEBUG:-0} && node scripts/preflight-production-security.mjs && node scripts/preflight-mongo-connection.mjs && node scripts/preflight-activitypub-rsa-key.mjs && node scripts/preflight-activitypub-profile-urls.mjs && node scripts/patch-lightningcss.mjs && node scripts/patch-endpoint-media-scope.mjs && node scripts/patch-endpoint-media-sharp-runtime.mjs && node scripts/patch-frontend-sharp-runtime.mjs && node scripts/patch-endpoint-files-upload-route.mjs && node scripts/patch-endpoint-files-upload-locales.mjs && node scripts/patch-endpoint-activitypub-locales.mjs && node scripts/patch-endpoint-activitypub-docloader-loglevel.mjs && node scripts/patch-endpoint-homepage-locales.mjs && node scripts/patch-federation-unlisted-guards.mjs && node scripts/patch-endpoint-micropub-where-note-visibility.mjs && node scripts/patch-preset-eleventy-ai-frontmatter.mjs && node scripts/patch-frontend-serviceworker-file.mjs && node scripts/patch-conversations-collection-guards.mjs && node scripts/patch-conversations-mastodon-disconnect.mjs && node scripts/patch-indiekit-routes-rate-limits.mjs && node scripts/patch-indiekit-error-production-stack.mjs && node scripts/patch-indieauth-devmode-guard.mjs && node scripts/patch-listening-endpoint-runtime-guards.mjs && node node_modules/@indiekit/indiekit/bin/cli.js serve --config indiekit.config.mjs",
     "test": "echo \"Error: no test specified\" && exit 1"
   },
   "keywords": [],
diff --git a/scripts/patch-preset-eleventy-ai-frontmatter.mjs b/scripts/patch-preset-eleventy-ai-frontmatter.mjs
new file mode 100644
index 00000000..a3f2b443
--- /dev/null
+++ b/scripts/patch-preset-eleventy-ai-frontmatter.mjs
@@ -0,0 +1,127 @@
+import { access, readFile, writeFile } from "node:fs/promises";
+
+const candidates = [
+  "node_modules/@rmdes/indiekit-preset-eleventy/lib/post-template.js",
+  "node_modules/@indiekit/preset-eleventy/lib/post-template.js",
+  "node_modules/@indiekit/indiekit/node_modules/@rmdes/indiekit-preset-eleventy/lib/post-template.js",
+  "node_modules/@indiekit/indiekit/node_modules/@indiekit/preset-eleventy/lib/post-template.js",
+];
+
+const patchMarker = "Normalize AI disclosure metadata and default to no AI usage.";
+
+const oldBlock = [
+  "  // Convert url to Eleventy permalink so generated URL matches Indiekit's stored URL",
+  "  // Add trailing slash to generate /path/index.html instead of /path.html",
+  "  if (properties.url) {",
+  "    const url = properties.url;",
+  "    properties.permalink = url.endsWith(\"/\") ? url : `${url}/`;",
+  "  }",
+  "  delete properties.url;",
+  "",
+  "  const frontMatter = YAML.stringify(properties, { lineWidth: 0 });",
+  "  return `---\\n${frontMatter}---\\n`;",
+  "};",
+].join("\n");
+
+const newBlock = [
+  "  // Convert url to Eleventy permalink so generated URL matches Indiekit's stored URL",
+  "  // Add trailing slash to generate /path/index.html instead of /path.html",
+  "  if (properties.url) {",
+  "    const url = properties.url;",
+  "    properties.permalink = url.endsWith(\"/\") ? url : `${url}/`;",
+  "  }",
+  "  delete properties.url;",
+  "",
+  "  // Normalize AI disclosure metadata and default to no AI usage.",
+  "  const aiSource =",
+  "    properties.ai && typeof properties.ai === \"object\" && !Array.isArray(properties.ai)",
+  "      ? properties.ai",
+  "      : {};",
+  "",
+  "  const aiTextLevel = String(",
+  "    aiSource.textLevel ?? aiSource.aiTextLevel ?? properties.aiTextLevel ?? \"0\",",
+  "  );",
+  "",
+  "  const aiCodeLevel = String(",
+  "    aiSource.codeLevel ?? aiSource.aiCodeLevel ?? properties.aiCodeLevel ?? \"0\",",
+  "  );",
+  "",
+  "  const aiTools = aiSource.aiTools ?? aiSource.tools ?? properties.aiTools;",
+  "",
+  "  const aiDescription =",
+  "    aiSource.aiDescription ?? aiSource.description ?? properties.aiDescription;",
+  "",
+  "  delete properties.ai;",
+  "  delete properties.aiTextLevel;",
+  "  delete properties.aiCodeLevel;",
+  "  delete properties.aiTools;",
+  "  delete properties.aiDescription;",
+  "",
+  "  const frontMatter = YAML.stringify(properties, { lineWidth: 0 });",
+  "",
+  "  let aiFrontMatter = `ai:\\n  textLevel: \\\"${aiTextLevel}\\\"\\n  codeLevel: \\\"${aiCodeLevel}\\\"\\n  # aiTools: \\\"Claude, ChatGPT, Copilot\\\"\\n  # aiDescription: \\\"Optional disclosure about how AI was used\\\"\\n`;",
+  "",
+  "  if (aiTools !== undefined && aiTools !== null && aiTools !== \"\") {",
+  "    aiFrontMatter = aiFrontMatter.replace(",
+  "      '  # aiTools: \\\"Claude, ChatGPT, Copilot\\\"\\n',",
+  "      `  aiTools: ${JSON.stringify(String(aiTools))}\\n`,",
+  "    );",
+  "  }",
+  "",
+  "  if (aiDescription !== undefined && aiDescription !== null && aiDescription !== \"\") {",
+  "    aiFrontMatter = aiFrontMatter.replace(",
+  "      '  # aiDescription: \\\"Optional disclosure about how AI was used\\\"\\n',",
+  "      `  aiDescription: ${JSON.stringify(String(aiDescription))}\\n`,",
+  "    );",
+  "  }",
+  "",
+  "  return `---\\n${frontMatter}${aiFrontMatter}---\\n`;",
+  "};",
+].join("\n");
+
+async function exists(filePath) {
+  try {
+    await access(filePath);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+let checked = 0;
+let patched = 0;
+
+for (const filePath of candidates) {
+  if (!(await exists(filePath))) {
+    continue;
+  }
+
+  checked += 1;
+
+  const source = await readFile(filePath, "utf8");
+
+  if (source.includes(patchMarker)) {
+    continue;
+  }
+
+  if (!source.includes(oldBlock)) {
+    console.warn(
+      `[postinstall] Skipping preset-eleventy AI frontmatter patch for ${filePath}: upstream format changed`,
+    );
+    continue;
+  }
+
+  const updated = source.replace(oldBlock, newBlock);
+  await writeFile(filePath, updated, "utf8");
+  patched += 1;
+}
+
+if (checked === 0) {
+  console.log("[postinstall] No preset-eleventy post-template files found");
+} else if (patched === 0) {
+  console.log("[postinstall] preset-eleventy AI frontmatter patch already applied");
+} else {
+  console.log(
+    `[postinstall] Patched preset-eleventy AI frontmatter in ${patched} file(s)`,
+  );
+}