Submit changed pages to Bing with IndexNow after each production deploy

.github/workflows/indexnow.yml

@@ -0,0 +1,29 @@
+name: IndexNow
+
+on:
+  deployment_status:
+  workflow_dispatch:
+    inputs:
+      all:
+        description: Submit every URL in the sitemap, not only recently changed pages
+        type: boolean
+        default: false
+
+permissions:
+  contents: read
+
+jobs:
+  submit:
+    if: >-
+      github.event_name == 'workflow_dispatch' ||
+      (github.event.deployment_status.state == 'success' &&
+      github.event.deployment.environment == 'Production')
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.event.deployment.sha || github.ref }}
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 22
+      - run: node scripts/indexnow.mjs ${{ inputs.all && '--all' || '' }}

public/f45f7e891bc3827c5178c9ff112a900c.txt

@@ -0,0 +1 @@
+f45f7e891bc3827c5178c9ff112a900c

scripts/indexnow.mjs

@@ -0,0 +1,67 @@
+import { pathToFileURL } from "node:url";
+import { siteConfig } from "../src/lib/site.js";
+
+export const ENDPOINT = "https://api.indexnow.org/indexnow";
+const DAY = 24 * 60 * 60 * 1000;
+
+export function locsFromSitemap(xml) {
+    return [...xml.matchAll(/<url>([\s\S]*?)<\/url>/g)]
+        .map(([, block]) => ({
+            loc: /<loc>([^<]+)<\/loc>/.exec(block)?.[1].trim(),
+            lastmod: /<lastmod>([^<]+)<\/lastmod>/.exec(block)?.[1].trim() ?? null,
+        }))
+        .filter((entry) => entry.loc);
+}
+
+export function pickUrls(entries, { all = false, sinceDays = 7, now = Date.now() } = {}) {
+    if (all) return entries.map((entry) => entry.loc);
+    const cutoff = now - sinceDays * DAY;
+    return entries
+        .filter((entry) => entry.lastmod && Date.parse(entry.lastmod) >= cutoff)
+        .map((entry) => entry.loc);
+}
+
+export function payload({ base, key, urls }) {
+    const { host, origin } = new URL(base);
+    return {
+        host,
+        key,
+        keyLocation: `${origin}/${key}.txt`,
+        urlList: urls.filter((url) => new URL(url).host === host),
+    };
+}
+
+async function main(argv) {
+    const flags = new Set(argv.filter((arg) => arg.startsWith("--")));
+    const base = (argv.find((arg) => !arg.startsWith("--")) ?? siteConfig.url).replace(/\/$/, "");
+    const sitemap = await fetch(`${base}/sitemap.xml`);
+    if (!sitemap.ok) throw new Error(`${base}/sitemap.xml returned ${sitemap.status}`);
+
+    const urls = pickUrls(locsFromSitemap(await sitemap.text()), { all: flags.has("--all") });
+    const body = payload({ base: siteConfig.url, key: siteConfig.indexNowKey, urls });
+    if (body.urlList.length === 0) {
+        console.log("No recently changed pages to submit.");
+        return;
+    }
+    if (flags.has("--dry-run")) {
+        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),
+    });
+    if (response.status !== 200 && response.status !== 202) {
+        throw new Error(`IndexNow returned ${response.status}: ${await response.text()}`);
+    }
+    console.log(`IndexNow accepted ${body.urlList.length} URLs (${response.status}).`);
+}
+
+if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
+    main(process.argv.slice(2)).catch((error) => {
+        console.error(error.message);
+        process.exit(1);
+    });
+}

src/lib/site.js

@@ -21,6 +21,7 @@ export const siteConfig = {
     },
     repo: "https://github.com/salsadsid/visualizer",
     feedbackUrl: `https://github.com/salsadsid/visualizer/issues/new?${feedbackParams}`,
+    indexNowKey: "f45f7e891bc3827c5178c9ff112a900c",
     keywords: [
         "DSA visualizer",
         "array visualizer",

tests/indexnow.test.mjs

@@ -0,0 +1,61 @@
+import test from "node:test";
+import assert from "node:assert/strict";
+import { readFileSync } from "node:fs";
+import { locsFromSitemap, payload, pickUrls } from "../scripts/indexnow.mjs";
+import { siteConfig } from "../src/lib/site.js";
+
+const SITEMAP = `<?xml version="1.0" encoding="UTF-8"?>
+<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
+<url>
+<loc>https://visualizer-gold.vercel.app/</loc>
+<lastmod>2026-10-20</lastmod>
+<changefreq>weekly</changefreq>
+<priority>1</priority>
+</url>
+<url>
+<loc>https://visualizer-gold.vercel.app/roadmap</loc>
+<lastmod>2026-09-19</lastmod>
+</url>
+<url>
+<loc>https://visualizer-gold.vercel.app/algorithms</loc>
+</url>
+</urlset>`;
+
+test("reads every url and its lastmod from a sitemap", () => {
+    assert.deepEqual(locsFromSitemap(SITEMAP), [
+        { loc: "https://visualizer-gold.vercel.app/", lastmod: "2026-10-20" },
+        { loc: "https://visualizer-gold.vercel.app/roadmap", lastmod: "2026-09-19" },
+        { loc: "https://visualizer-gold.vercel.app/algorithms", lastmod: null },
+    ]);
+});
+
+test("submits only pages changed within the last seven days unless asked for all", () => {
+    const entries = locsFromSitemap(SITEMAP);
+    const edge = Date.parse("2026-10-27T00:00:00Z");
+    assert.deepEqual(pickUrls(entries, { now: edge }), ["https://visualizer-gold.vercel.app/"]);
+    assert.deepEqual(pickUrls(entries, { now: edge + 1000 }), []);
+    assert.deepEqual(
+        pickUrls(entries, { all: true, now: edge }),
+        entries.map((entry) => entry.loc)
+    );
+});
+
+test("builds a payload whose urls all sit on the key's host", () => {
+    const body = payload({
+        base: "https://visualizer-gold.vercel.app",
+        key: "abc123",
+        urls: ["https://visualizer-gold.vercel.app/", "https://elsewhere.example/page"],
+    });
+    assert.deepEqual(body, {
+        host: "visualizer-gold.vercel.app",
+        key: "abc123",
+        keyLocation: "https://visualizer-gold.vercel.app/abc123.txt",
+        urlList: ["https://visualizer-gold.vercel.app/"],
+    });
+});
+
+test("the key file in public/ holds exactly the configured key", () => {
+    assert.match(siteConfig.indexNowKey, /^[a-f0-9]{32}$/);
+    const file = new URL(`../public/${siteConfig.indexNowKey}.txt`, import.meta.url);
+    assert.equal(readFileSync(file, "utf8"), siteConfig.indexNowKey);
+});