diff --git a/src/routes/authenticator/sync-confirmed/+page.js b/src/routes/authenticator/sync-confirmed/+page.js
new file mode 100644
index 0000000..9560cbe
--- /dev/null
+++ b/src/routes/authenticator/sync-confirmed/+page.js
@@ -0,0 +1,9 @@
+export function load() {
+  return {
+    meta: {
+      title: 'Signed in | Authenticator',
+      description: 'Your Authenticator Cloud Sync sign-in was confirmed.',
+      type: 'authenticator-sync-confirmed'
+    }
+  };
+}
diff --git a/src/routes/authenticator/sync-confirmed/+page.svelte b/src/routes/authenticator/sync-confirmed/+page.svelte
new file mode 100644
index 0000000..2703d08
--- /dev/null
+++ b/src/routes/authenticator/sync-confirmed/+page.svelte
@@ -0,0 +1,53 @@
+<main>
+  <div class="card">
+    <div class="mark"><span class="dot"></span>Authenticator</div>
+    <h1>You're signed in</h1>
+    <p>
+      Cloud Sync sign-in was confirmed. If you're not returned to the app automatically, switch back
+      to Authenticator — you can close this tab.
+    </p>
+  </div>
+</main>
+
+<style lang="scss">
+  main {
+    @include flex(column, center, center);
+
+    height: 100%;
+    max-height: calc(100vh - $spacing-8xl);
+  }
+
+  .card {
+    width: 100%;
+    max-width: 380px;
+    text-align: center;
+  }
+
+  .mark {
+    @include flex(row, center, center);
+
+    gap: $spacing-xs;
+    font-size: $font-sm;
+    font-weight: 600;
+    color: var(--txt-2);
+    margin-bottom: $spacing-xl;
+  }
+
+  .dot {
+    width: 8px;
+    height: 8px;
+    border-radius: 999px;
+    background: var(--green);
+  }
+
+  h1 {
+    font-size: $font-xl;
+    margin: 0 0 $spacing-sm;
+  }
+
+  p {
+    margin: 0;
+    color: var(--txt-2);
+    line-height: 1.5;
+  }
+</style>
diff --git a/src/routes/unkee/sync-confirmed/+page.js b/src/routes/unkee/sync-confirmed/+page.js
new file mode 100644
index 0000000..11b9f8a
--- /dev/null
+++ b/src/routes/unkee/sync-confirmed/+page.js
@@ -0,0 +1,9 @@
+export function load() {
+  return {
+    meta: {
+      title: 'Signed in | UnKee',
+      description: 'Your UnKee Cloud Sync sign-in was confirmed.',
+      type: 'unkee-sync-confirmed'
+    }
+  };
+}
diff --git a/src/routes/unkee/sync-confirmed/+page.svelte b/src/routes/unkee/sync-confirmed/+page.svelte
new file mode 100644
index 0000000..bc273ca
--- /dev/null
+++ b/src/routes/unkee/sync-confirmed/+page.svelte
@@ -0,0 +1,53 @@
+<main>
+  <div class="card">
+    <div class="mark"><span class="dot"></span>UnKee</div>
+    <h1>You're signed in</h1>
+    <p>
+      Cloud Sync sign-in was confirmed. If you're not returned to the app automatically, switch back
+      to UnKee — you can close this tab.
+    </p>
+  </div>
+</main>
+
+<style lang="scss">
+  main {
+    @include flex(column, center, center);
+
+    height: 100%;
+    max-height: calc(100vh - $spacing-8xl);
+  }
+
+  .card {
+    width: 100%;
+    max-width: 380px;
+    text-align: center;
+  }
+
+  .mark {
+    @include flex(row, center, center);
+
+    gap: $spacing-xs;
+    font-size: $font-sm;
+    font-weight: 600;
+    color: var(--txt-2);
+    margin-bottom: $spacing-xl;
+  }
+
+  .dot {
+    width: 8px;
+    height: 8px;
+    border-radius: 999px;
+    background: var(--green);
+  }
+
+  h1 {
+    font-size: $font-xl;
+    margin: 0 0 $spacing-sm;
+  }
+
+  p {
+    margin: 0;
+    color: var(--txt-2);
+    line-height: 1.5;
+  }
+</style>
diff --git a/static/.well-known/apple-app-site-association b/static/.well-known/apple-app-site-association
index 51c0e74..107b660 100644
--- a/static/.well-known/apple-app-site-association
+++ b/static/.well-known/apple-app-site-association
@@ -10,11 +10,20 @@
           { "/": "/unkee/autofill/*", "comment": "AutoFill unlock-stub hands off after Face ID" },
           { "/": "/unkee/open", "comment": "Spotlight tap / Siri intent / App Shortcut" },
           { "/": "/unkee/open/*", "comment": "Spotlight tap / Siri intent / App Shortcut" },
+          { "/": "/unkee/sync-confirmed", "comment": "Cloud Sync magic-link confirm hands back to the app" },
+          { "/": "/unkee/sync-confirmed/*", "comment": "Cloud Sync magic-link confirm hands back to the app" },
           { "/": "/unkee/passkey-create", "comment": "Passkey registration ceremony" },
           { "/": "/unkee/passkey-create/*", "comment": "Passkey registration ceremony" },
           { "/": "/unkee/passkey-get", "comment": "Passkey assertion ceremony" },
           { "/": "/unkee/passkey-get/*", "comment": "Passkey assertion ceremony" }
         ]
+      },
+      {
+        "appIDs": ["293M4MWUJC.dev.techquests.unkeeauth"],
+        "components": [
+          { "/": "/authenticator/sync-confirmed", "comment": "Cloud Sync magic-link confirm hands back to the app" },
+          { "/": "/authenticator/sync-confirmed/*", "comment": "Cloud Sync magic-link confirm hands back to the app" }
+        ]
       }
     ]
   },