diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7f09927..d3e7202 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ The format follows [Keep a Changelog](https://keepachangelog.com/en/1.1.0/), and
 
 ### Changed
 
+- Source Vault identity: its own favicon (the vault's `>_` prompt in a gradient frame, with a 32 px PNG and an iPhone home-screen icon), page tags (title "Source Vault · ERROR_404", description "Restricted. Access key required.") and a share image for link previews: the logo beside the Nº 404 seal and ACCESS REQUIRED, in the same frame as the main site's. The tags never mention what's inside, and the vault stays noindex and blocked from search and AI crawlers.
 - Source Vault: the STYLES stat in the header is now GENRE: HYPERPOP (was STYLES: 5 + NONE).
 - Intros: the site intro and the vault's unlock intro now carry the ACCESS REQUIRED page's soft violet glow over the rain (one shared layer, same colour, size and position), in place of their dark edge vignette, so the gate → unlock hand-off keeps the same light.
 - Source Vault: the access number is now **Nº404** everywhere (nav, phone menu, header seal, stats, end credits, unlock intro). With the stems uploaded, the "SOON" / "UPLOADING SOON" placeholders are gone: the STEMS stat counts the stems (220, each as WAV + MIDI), ALL STEMS shows its total size once the release answers, each track's stems tab shows its stem count, the intro line reads "full stems as WAV and MIDI", and a failed download now says UNAVAILABLE · TRY AGAIN instead of NOT UPLOADED YET.
diff --git a/public/vault/apple-touch-icon.png b/public/vault/apple-touch-icon.png
new file mode 100644
index 0000000..45d5d9e
Binary files /dev/null and b/public/vault/apple-touch-icon.png differ
diff --git a/public/vault/favicon-32.png b/public/vault/favicon-32.png
new file mode 100644
index 0000000..febb0fb
Binary files /dev/null and b/public/vault/favicon-32.png differ
diff --git a/public/vault/favicon.svg b/public/vault/favicon.svg
new file mode 100644
index 0000000..cfdd43d
--- /dev/null
+++ b/public/vault/favicon.svg
@@ -0,0 +1 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 64 64"><defs><linearGradient id="g" x1="0" y1="0" x2="1" y2="0"><stop offset="0" stop-color="#FF00E5"/><stop offset="1" stop-color="#00EFFF"/></linearGradient></defs><rect width="64" height="64" rx="14" fill="#030409"/><rect x="3" y="3" width="58" height="58" rx="11" fill="none" stroke="url(#g)" stroke-width="2.5"/><path d="M14 20l13 12-13 12" fill="none" stroke="url(#g)" stroke-width="6.5" stroke-linecap="square"/><rect x="31" y="41" width="20" height="6.5" fill="url(#g)"/></svg>
diff --git a/public/vault/og-vault.png b/public/vault/og-vault.png
new file mode 100644
index 0000000..b65e2ff
Binary files /dev/null and b/public/vault/og-vault.png differ
diff --git a/vault/index.html b/vault/index.html
index d502751..de9134d 100644
--- a/vault/index.html
+++ b/vault/index.html
@@ -3,14 +3,36 @@
   <head>
     <meta charset="UTF-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0, viewport-fit=cover" />
-    <meta name="theme-color" content="#000000" />
+    <meta name="theme-color" content="#030409" />
+    <!-- kept out of every search engine and AI index (also robots.txt + the X-Robots-Tag header) -->
     <meta name="robots" content="noindex, nofollow, noarchive, nosnippet, noimageindex, noai, noimageai" />
     <meta name="tdm-reservation" content="1" />
     <meta name="referrer" content="no-referrer" />
     <title>Source Vault · ERROR_404</title>
-    <link rel="icon" href="/favicon.ico" sizes="32x32" />
-    <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
-    <link rel="apple-touch-icon" sizes="180x180" href="/apple-touch-icon.png" />
+    <meta name="description" content="Restricted. Access key required." />
+    <link rel="canonical" href="https://error404.run/vault/" />
+    <link rel="icon" type="image/svg+xml" href="/vault/favicon.svg" />
+    <link rel="icon" type="image/png" sizes="32x32" href="/vault/favicon-32.png" />
+    <link rel="apple-touch-icon" sizes="180x180" href="/vault/apple-touch-icon.png" />
+    <meta name="apple-mobile-web-app-title" content="VAULT" />
+
+    <!-- link previews in chat apps: say only that it's private, never what's inside -->
+    <meta property="og:type" content="website" />
+    <meta property="og:url" content="https://error404.run/vault/" />
+    <meta property="og:site_name" content="ERROR_404" />
+    <meta property="og:title" content="Source Vault · ERROR_404" />
+    <meta property="og:description" content="Restricted. Access key required." />
+    <meta property="og:image" content="https://error404.run/vault/og-vault.png" />
+    <meta
+      property="og:image:alt"
+      content="The ERROR_404 logo beside a tilted Nº 404 Source Vault seal and the words ACCESS REQUIRED"
+    />
+    <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:title" content="Source Vault · ERROR_404" />
+    <meta name="twitter:description" content="Restricted. Access key required." />
+    <meta name="twitter:image" content="https://error404.run/vault/og-vault.png" />
     <link rel="preload" href="/fonts/bebas-neue-400.woff2" as="font" type="font/woff2" crossorigin />
     <link rel="stylesheet" href="/fonts/fonts.css" />
     <link rel="preconnect" href="https://fonts.googleapis.com" />