diff --git a/package.json b/package.json
index 82a61c0..ecd8e14 100644
--- a/package.json
+++ b/package.json
@@ -17,7 +17,8 @@
     "typecheck": "astro check",
     "lint": "eslint .",
     "format": "prettier --write .",
-    "format:check": "prettier --check ."
+    "format:check": "prettier --check .",
+    "indexnow": "node scripts/indexnow.mjs"
   },
   "devDependencies": {
     "@astrojs/check": "^0.9.10",
diff --git a/public/13a43bd0c536446eaca1c087990db4fa.txt b/public/13a43bd0c536446eaca1c087990db4fa.txt
new file mode 100644
index 0000000..5811843
--- /dev/null
+++ b/public/13a43bd0c536446eaca1c087990db4fa.txt
@@ -0,0 +1 @@
+13a43bd0c536446eaca1c087990db4fa
\ No newline at end of file
diff --git a/scripts/indexnow.mjs b/scripts/indexnow.mjs
new file mode 100644
index 0000000..0237013
--- /dev/null
+++ b/scripts/indexnow.mjs
@@ -0,0 +1,81 @@
+#!/usr/bin/env node
+/**
+ * Tell the IndexNow participants that these pages changed.
+ *
+ * Deliberately a command someone runs, not a step in the deploy. Three static
+ * pages that change when a version ships do not need a push protocol firing on
+ * every build, and a hook that submits unchanged pages on every commit is how a
+ * domain earns a rate limit.
+ *
+ * Run it after a release that changed the site:
+ *
+ *     node scripts/indexnow.mjs
+ *     node scripts/indexnow.mjs --dry-run
+ *
+ * Who listens: Bing, Yandex, Naver, Seznam, Yep and Amazon. Google is not a
+ * participant, so this does nothing for Google Search and nothing for AI
+ * Overviews. Search Console's URL Inspection is the equivalent there, and it is
+ * a button rather than an API.
+ *
+ * The key is not a secret. IndexNow verifies ownership by requiring the key to
+ * be readable at the domain it authorises, so it is public by design and
+ * authorises nothing anywhere else.
+ */
+
+const HOST = 'agentchaperone.dev';
+const KEY = '13a43bd0c536446eaca1c087990db4fa';
+const ENDPOINT = 'https://api.indexnow.org/indexnow';
+
+/** Everything worth announcing. The markdown twins are the same content. */
+const URLS = [`https://${HOST}/`, `https://${HOST}/results`];
+
+async function main() {
+  const dryRun = process.argv.includes('--dry-run');
+  const keyLocation = `https://${HOST}/${KEY}.txt`;
+
+  // Submitting before the key file is reachable is rejected, and the rejection
+  // does not say why. Checked first so the failure names its own cause.
+  const hosted = await fetch(keyLocation).catch(() => undefined);
+  if (hosted === undefined || !hosted.ok) {
+    console.error(`The key is not readable at ${keyLocation}, so a submission would be refused.`);
+    console.error('Deploy the site first; the file lives in public/.');
+    process.exit(1);
+  }
+  const served = (await hosted.text()).trim();
+  if (served !== KEY) {
+    console.error(`${keyLocation} does not contain the key it should.`);
+    process.exit(1);
+  }
+
+  const body = { host: HOST, key: KEY, keyLocation, urlList: URLS };
+  if (dryRun) {
+    console.log('Would submit:');
+    console.log(JSON.stringify(body, null, 2));
+    return;
+  }
+
+  const response = await fetch(ENDPOINT, {
+    method: 'POST',
+    headers: { 'content-type': 'application/json; charset=utf-8' },
+    body: JSON.stringify(body),
+  });
+
+  // 200 is accepted, 202 is accepted with the key still being validated. Both
+  // mean the submission landed.
+  if (response.status === 200 || response.status === 202) {
+    console.log(`Submitted ${URLS.length} URLs (HTTP ${response.status}).`);
+    return;
+  }
+  const why = {
+    400: 'the request was malformed',
+    403: 'the key was rejected for this host',
+    422: 'a URL did not belong to this host, or the key did not match',
+    429: 'too many submissions; wait rather than retrying',
+  };
+  console.error(
+    `IndexNow refused it: HTTP ${response.status}, ${why[response.status] ?? 'unknown'}`,
+  );
+  process.exit(1);
+}
+
+await main();