diff --git a/frontend/design-system/preview/og-card.html b/frontend/design-system/preview/og-card.html
new file mode 100644
index 0000000000..7808a0b85d
--- /dev/null
+++ b/frontend/design-system/preview/og-card.html
@@ -0,0 +1,82 @@
+<!DOCTYPE html>
+<!--
+  Link-preview card (og:image + twitter:image) — the source of
+  frontend/public/og-card.png. Edit this file, then regenerate from frontend/
+  (after npm ci, so the @fontsource files below resolve):
+
+    npx playwright screenshot --viewport-size=1200,630 --wait-for-timeout=1500 \
+      "file://$PWD/design-system/preview/og-card.html" public/og-card.png
+
+  Then bump ?v=N on og:image and twitter:image in index.html and
+  scripts/generate-seo-pages.mjs so scrapers re-fetch; og-card.test.mjs
+  checks that the three URLs agree and the PNG stays 1200x630.
+
+  Signal front door (docs/design/signal-identity.md): a cobalt block, the
+  display line in Bricolage, one sentence at 86% white, one mono footer. No
+  shadow, no gradient, no green.
+-->
+<html lang="en"><head><meta charset="utf-8"><title>og-card</title>
+<style>
+  @font-face { font-family: "Bricolage Grotesque Variable"; font-weight: 200 800;
+    src: url("../../node_modules/@fontsource-variable/bricolage-grotesque/files/bricolage-grotesque-latin-wght-normal.woff2") format("woff2"); }
+  @font-face { font-family: "IBM Plex Sans"; font-weight: 400;
+    src: url("../../node_modules/@fontsource/ibm-plex-sans/files/ibm-plex-sans-latin-400-normal.woff2") format("woff2"); }
+  @font-face { font-family: "IBM Plex Mono"; font-weight: 500;
+    src: url("../../node_modules/@fontsource/ibm-plex-mono/files/ibm-plex-mono-latin-500-normal.woff2") format("woff2"); }
+
+  html, body { margin: 0; }
+  .card {
+    box-sizing: border-box;
+    width: 1200px; height: 630px;
+    padding: 64px 80px 56px;
+    display: flex; flex-direction: column;
+    background: #1d3fd1;
+    color: #ffffff;
+    -webkit-font-smoothing: antialiased;
+  }
+  .brand { display: flex; align-items: center; gap: 12px; }
+  .brand svg { width: 44px; height: 44px; color: #ffffff; }
+  .brand-name {
+    font-family: "Bricolage Grotesque Variable", sans-serif;
+    font-size: 32px; font-weight: 800; letter-spacing: -0.03em;
+  }
+  .title {
+    margin: auto 0 0;
+    max-width: 1000px;
+    font-family: "Bricolage Grotesque Variable", sans-serif;
+    font-size: 72px; line-height: 76px; font-weight: 800; letter-spacing: -0.03em;
+    text-wrap: balance;
+  }
+  .sub {
+    margin: 28px 0 0;
+    max-width: 920px;
+    font-family: "IBM Plex Sans", sans-serif;
+    font-size: 26px; line-height: 36px; font-weight: 400;
+    color: rgba(255, 255, 255, 0.86);
+    text-wrap: pretty;
+  }
+  .foot {
+    margin-top: 40px; padding-top: 20px;
+    border-top: 1px solid rgba(255, 255, 255, 0.28);
+    display: flex; justify-content: space-between;
+    font-family: "IBM Plex Mono", monospace;
+    font-size: 20px; font-weight: 500;
+    color: rgba(255, 255, 255, 0.86);
+  }
+</style></head><body>
+<div class="card">
+  <div class="brand">
+    <!-- frontend/design-system/assets/commonly-mark.svg, inlined so currentColor is white -->
+    <svg viewBox="0 0 64 64" aria-hidden="true">
+      <path d="M 50 17.7 A 22 22 0 1 0 50 46.3" fill="none" stroke="currentColor" stroke-width="9" stroke-linecap="round"></path>
+      <circle cx="25" cy="32" r="2.4" fill="currentColor"></circle>
+      <circle cx="32" cy="32" r="2.4" fill="currentColor"></circle>
+      <circle cx="39" cy="32" r="2.4" fill="currentColor"></circle>
+    </svg>
+    <span class="brand-name">Commonly</span>
+  </div>
+  <h1 class="title">One pod for your team and the agents each of you runs.</h1>
+  <p class="sub">Open source (Apache-2.0). People and their own agents share the same conversations and one task board.</p>
+  <div class="foot"><span>commonly.me</span><span>github.com/Team-Commonly/commonly</span></div>
+</div>
+</body></html>
diff --git a/frontend/index.html b/frontend/index.html
index 4a288d1192..2bad99770e 100644
--- a/frontend/index.html
+++ b/frontend/index.html
@@ -21,14 +21,14 @@
     <meta property="og:url" content="https://commonly.me/" />
     <meta property="og:title" content="Commonly — chat with your agents, ship real work" />
     <meta property="og:description" content="The open-source workspace where agents and teammates share one project memory — so nothing gets re-explained. Any runtime, your infra, no per-agent fees." />
-    <meta property="og:image" content="https://commonly.me/og-card.png?v=2" />
+    <meta property="og:image" content="https://commonly.me/og-card.png?v=3" />
     <meta property="og:image:width" content="1200" />
     <meta property="og:image:height" content="630" />
     <meta name="twitter:card" content="summary_large_image" />
     <meta name="twitter:site" content="@sam_commonly" />
     <meta name="twitter:title" content="Commonly — chat with your agents, ship real work" />
     <meta name="twitter:description" content="The open-source workspace where you and your agents share one project memory — so nothing gets re-explained. Any runtime, your infra, no per-agent fees." />
-    <meta name="twitter:image" content="https://commonly.me/og-card.png?v=2" />
+    <meta name="twitter:image" content="https://commonly.me/og-card.png?v=3" />
     <!-- SEO_METADATA_END -->
     <!-- Progressive-enhancement gate for the prerendered SEO page below.
          The #seo-page markup ships inside #root on EVERY route, so
diff --git a/frontend/package.json b/frontend/package.json
index 2bff530cd6..e65b44e22e 100644
--- a/frontend/package.json
+++ b/frontend/package.json
@@ -40,7 +40,7 @@
     "start": "vite",
     "build": "vite build && node scripts/generate-seo-pages.mjs",
     "preview": "vite preview",
-    "test": "jest --watchAll=false --forceExit && node --test scripts/generate-seo-pages.test.mjs scripts/nginx-routing.test.mjs scripts/signup-source.test.mjs scripts/ui-card-catalogue.test.mjs",
+    "test": "jest --watchAll=false --forceExit && node --test scripts/generate-seo-pages.test.mjs scripts/nginx-routing.test.mjs scripts/signup-source.test.mjs scripts/ui-card-catalogue.test.mjs scripts/og-card.test.mjs",
     "test:coverage": "jest --coverage --watchAll=false --forceExit",
     "typecheck": "tsc --noEmit",
     "lint": "eslint src --ext .js,.jsx,.ts,.tsx",
diff --git a/frontend/public/og-card.png b/frontend/public/og-card.png
index ef36ecbdf9..bcd76ea246 100644
Binary files a/frontend/public/og-card.png and b/frontend/public/og-card.png differ
diff --git a/frontend/scripts/generate-seo-pages.mjs b/frontend/scripts/generate-seo-pages.mjs
index 1d18cf28d1..6b8c563656 100644
--- a/frontend/scripts/generate-seo-pages.mjs
+++ b/frontend/scripts/generate-seo-pages.mjs
@@ -419,7 +419,7 @@ const metadata = ({ title, description, path, schema, faqSchema, ogType = 'websi
     <meta property="og:url" content="${url}" />
     <meta property="og:title" content="${escapeHtml(title)}" />
     <meta property="og:description" content="${escapeHtml(description)}" />
-    <meta property="og:image" content="${siteUrl}/og-card.png?v=2" />
+    <meta property="og:image" content="${siteUrl}/og-card.png?v=3" />
     <meta property="og:image:width" content="1200" />
     <meta property="og:image:height" content="630" />
     ${articleDates}
@@ -427,7 +427,7 @@ const metadata = ({ title, description, path, schema, faqSchema, ogType = 'websi
     <meta name="twitter:site" content="@sam_commonly" />
     <meta name="twitter:title" content="${escapeHtml(title)}" />
     <meta name="twitter:description" content="${escapeHtml(description)}" />
-    <meta name="twitter:image" content="${siteUrl}/og-card.png?v=2" />
+    <meta name="twitter:image" content="${siteUrl}/og-card.png?v=3" />
     <script type="application/ld+json">${structuredData}</script>${faqSchema ? `
     <script type="application/ld+json" id="${faqJsonLdId}">${jsonLd(faqSchema)}</script>` : ''}`;
 };
diff --git a/frontend/scripts/og-card.test.mjs b/frontend/scripts/og-card.test.mjs
new file mode 100644
index 0000000000..3c6de7f865
--- /dev/null
+++ b/frontend/scripts/og-card.test.mjs
@@ -0,0 +1,30 @@
+import test from 'node:test';
+import assert from 'node:assert/strict';
+import { readFile } from 'node:fs/promises';
+
+const read = (path) => readFile(new URL(path, import.meta.url));
+const versions = (text) => [...text.matchAll(/og-card\.png\?v=(\d+)/g)].map((m) => m[1]);
+
+// The card is regenerated from design-system/preview/og-card.html; scrapers cache
+// by URL, so every og:image and twitter:image must carry the same bumped ?v=N.
+test('index.html and the SEO generator point at the same og-card version', async () => {
+  const index = versions(String(await read('../index.html')));
+  const seo = versions(String(await read('./generate-seo-pages.mjs')));
+  assert.equal(index.length, 2, 'index.html: og:image + twitter:image');
+  assert.equal(seo.length, 2, 'generate-seo-pages.mjs: og:image + twitter:image');
+  assert.deepEqual(new Set([...index, ...seo]), new Set(['3']));
+});
+
+test('og-card.png stays 1200x630', async () => {
+  const png = await read('../public/og-card.png');
+  assert.equal(png.toString('ascii', 12, 16), 'IHDR');
+  assert.equal(png.readUInt32BE(16), 1200);
+  assert.equal(png.readUInt32BE(20), 630);
+});
+
+test('the committed card source carries the D129 copy and none of the ruled-out claims', async () => {
+  const html = String(await read('../design-system/preview/og-card.html'));
+  assert.match(html, /One pod for your team and the agents each of you runs\./);
+  assert.match(html, /Open source \(Apache-2\.0\)\. People and their own agents share the same conversations and one task board\./);
+  for (const banned of [/one thread/i, /any runtime/i, /\$\d/]) assert.doesNotMatch(html, banned);
+});