diff --git a/nextjs-app/__tests__/app/metadata.test.ts b/nextjs-app/__tests__/app/metadata.test.ts
index 800c19d..edfbddb 100644
--- a/nextjs-app/__tests__/app/metadata.test.ts
+++ b/nextjs-app/__tests__/app/metadata.test.ts
@@ -2,6 +2,7 @@ import { metadata as homeMetadata } from '@/app/(frontend)/page';
 import { metadata as rankingsMetadata } from '@/app/(frontend)/rankings/page';
 import { metadata as admissionsMetadata } from '@/app/(frontend)/admissions/page';
 import { generateMetadata as compareMetadata } from '@/app/(frontend)/compare/page';
+import { metadata as rootMetadata } from '@/app/(frontend)/layout';
 
 describe('canonical URLs', () => {
   it('the homepage canonicalises to the bare root', () => {
@@ -128,3 +129,41 @@ describe('C1 snippet copy', () => {
     }
   });
 });
+
+/**
+ * The share card must be declared, not inherited.
+ *
+ * `app/opengraph-image.tsx` is a metadata file convention, and it does attach
+ * to routes in the app root segment — `_not-found` gets an og:image from it.
+ * It does NOT attach to the site's pages, which live in the `(frontend)`
+ * route group whose own layout is a root layout. Staging served og:title,
+ * og:description, og:url, og:site_name and og:type and no og:image at all,
+ * so every link pasted into a chat rendered bare.
+ *
+ * The file stays at the app root, because /robots.txt and /icon.png depend on
+ * it being there. The site's root layout points at the route it generates.
+ */
+describe('the share card', () => {
+  it('declares an opengraph image on the site root layout', () => {
+    // No og:image means every link pasted into a chat renders bare.
+    const images = rootMetadata.openGraph?.images;
+    expect(images).toBeTruthy();
+    expect(JSON.stringify(images)).toContain('/opengraph-image');
+  });
+
+  it('declares a twitter image too', () => {
+    // twitter.card is summary_large_image. Claiming a large-image card and
+    // supplying no image is worse than claiming a summary card.
+    // Metadata['twitter'] is a union and `card` is not on every member, so
+    // this reads the serialised shape rather than narrowing the type.
+    const twitter = JSON.stringify(rootMetadata.twitter);
+    expect(twitter).toContain('summary_large_image');
+    expect(twitter).toContain('/opengraph-image');
+  });
+
+  it('resolves the card to an absolute url via metadataBase', () => {
+    // The e2e journey does `new URL(ogUrl)`, which throws on a relative path.
+    expect(rootMetadata.metadataBase?.toString())
+      .toBe('https://www.schoolcompare.co.uk/');
+  });
+});
diff --git a/nextjs-app/app/(frontend)/layout.tsx b/nextjs-app/app/(frontend)/layout.tsx
index f41880d..7507073 100644
--- a/nextjs-app/app/(frontend)/layout.tsx
+++ b/nextjs-app/app/(frontend)/layout.tsx
@@ -59,14 +59,32 @@ export const metadata: Metadata = {
   authors: [{ name: 'schoolcompare' }],
   manifest: '/manifest.json',
   // No `icons` key on purpose: setting it here would override the file
-  // conventions. app/icon.svg and app/apple-icon.tsx are the source, and
-  // app/opengraph-image.tsx supplies og:image and twitter:image.
+  // conventions. app/icon.png and app/apple-icon.png are the source.
+  //
+  // og:image and twitter:image are NOT inherited from
+  // app/opengraph-image.tsx — see the note on openGraph.images below. The
+  // icon conventions do reach these pages; the opengraph-image one does not.
   metadataBase: new URL(SITE_URL),
   openGraph: {
     type: 'website',
     title: 'Compare Schools Side by Side | schoolcompare',
     description:
       'Put five English schools on one screen — SATs, GCSE results, Ofsted grades, and how close you had to live to get a place.',
+    /*
+     * Declared, not inherited.
+     *
+     * app/opengraph-image.tsx is a metadata file convention, and it does
+     * attach to routes in the app root segment — _not-found gets an og:image
+     * from it. It does not reach the site's pages, which live in the
+     * (frontend) route group whose own layout.tsx is a root layout. Staging
+     * served og:title, og:description, og:url, og:site_name and og:type with
+     * no og:image at all, so every link pasted into a chat rendered bare.
+     *
+     * The file stays at the app root: /robots.txt and /icon.png depend on it
+     * being there, and moving it is what broke those before. This points at
+     * the route it generates instead. metadataBase makes it absolute.
+     */
+    images: ['/opengraph-image'],
     url: SITE_URL,
     siteName: 'schoolcompare',
   },
@@ -76,6 +94,9 @@ export const metadata: Metadata = {
     title: 'Compare Schools Side by Side | schoolcompare',
     description:
       'Put five English schools on one screen — SATs, GCSE results, Ofsted grades, and how close you had to live to get a place.',
+    // The card is summary_large_image; claiming that and supplying no image
+    // is worse than claiming a summary card.
+    images: ['/opengraph-image'],
   },
 };