diff --git a/backend/app/data/registry_index.json b/backend/app/data/registry_index.json
index 623e03e7..edd65ab9 100644
--- a/backend/app/data/registry_index.json
+++ b/backend/app/data/registry_index.json
@@ -42,7 +42,8 @@
       "repo": "https://github.com/jhd3197/serverkit-crowdsec",
       "homepage": "https://github.com/jhd3197/serverkit-crowdsec",
       "featured": false,
-      "feature_score": 0
+      "feature_score": 0,
+      "logo": "assets/serverkit-crowdsec/logo.png"
     },
     {
       "slug": "serverkit-dns-server",
@@ -64,7 +65,8 @@
       "repo": "https://github.com/jhd3197/serverkit-dns-server",
       "homepage": "https://github.com/jhd3197/serverkit-dns-server",
       "featured": false,
-      "feature_score": 0
+      "feature_score": 0,
+      "logo": "assets/serverkit-dns-server/logo.png"
     },
     {
       "slug": "serverkit-gpu",
@@ -85,7 +87,8 @@
       "repo": "https://github.com/jhd3197/serverkit-gpu",
       "homepage": "https://github.com/jhd3197/serverkit-gpu",
       "featured": true,
-      "feature_score": 60
+      "feature_score": 60,
+      "logo": "assets/serverkit-gpu/logo.png"
     },
     {
       "slug": "serverkit-mail",
@@ -109,7 +112,8 @@
       "repo": "https://github.com/jhd3197/serverkit-mail",
       "homepage": "https://github.com/jhd3197/serverkit-mail",
       "featured": false,
-      "feature_score": 0
+      "feature_score": 0,
+      "logo": "assets/serverkit-mail/logo.png"
     },
     {
       "slug": "serverkit-k8s",
@@ -132,7 +136,8 @@
       "repo": "https://github.com/jhd3197/serverkit-k8s",
       "homepage": "https://github.com/jhd3197/serverkit-k8s",
       "featured": false,
-      "feature_score": 0
+      "feature_score": 0,
+      "logo": "assets/serverkit-k8s/logo.png"
     },
     {
       "slug": "serverkit-tramo",
@@ -156,7 +161,8 @@
       "repo": "https://github.com/jhd3197/serverkit-tramo",
       "homepage": "https://github.com/jhd3197/serverkit-tramo",
       "featured": true,
-      "feature_score": 90
+      "feature_score": 90,
+      "logo": "assets/serverkit-tramo/logo.png"
     },
     {
       "slug": "serverkit-analytics",
@@ -179,7 +185,8 @@
       "repo": "https://github.com/jhd3197/serverkit-analytics",
       "homepage": "https://github.com/jhd3197/serverkit-analytics",
       "featured": true,
-      "feature_score": 88
+      "feature_score": 88,
+      "logo": "assets/serverkit-analytics/logo.png"
     },
     {
       "slug": "serverkit-faro",
@@ -198,7 +205,8 @@
       "repo": "https://github.com/jhd3197/serverkit-faro",
       "homepage": "https://github.com/jhd3197/serverkit-faro",
       "featured": true,
-      "feature_score": 100
+      "feature_score": 100,
+      "logo": "assets/serverkit-faro/logo.png"
     }
   ]
 }
diff --git a/backend/app/services/registry_service.py b/backend/app/services/registry_service.py
index 68c7305c..a62de3ac 100644
--- a/backend/app/services/registry_service.py
+++ b/backend/app/services/registry_service.py
@@ -32,14 +32,12 @@ _BUNDLED_INDEX = os.path.join(
 # The curated public index (one JSON file, PR-reviewed, checksum-verified
 # installs). Panels fall back to cache → bundled copy when unreachable.
 #
-# NOTE (plan 40 task 11): once serverkit.ai/ext/index.json is deployed (Phase 4
-# endpoints), flip this default to 'https://serverkit.ai/ext/index.json' — that
-# endpoint proxies this same raw index with caching + logo URL rewriting. The
-# raw-GitHub URL below stays the documented manual fallback
-# (SERVERKIT_REGISTRY_URL). Deferred here: flipping before the domain is live
-# would break Marketplace Browse everywhere.
+# The default goes through serverkit.ai, which proxies the raw-GitHub index
+# with caching, serves logo art locally, and rewrites relative logo paths to
+# absolute serverkit.ai URLs. The raw-GitHub index stays available as a
+# manual fallback via SERVERKIT_REGISTRY_URL.
 DEFAULT_REGISTRY_URL = (
-    'https://raw.githubusercontent.com/jhd3197/serverkit-extensions/main/index.json'
+    'https://serverkit.ai/ext/index.json'
 )
 
 
diff --git a/backend/tests/test_registry.py b/backend/tests/test_registry.py
index 3283bbca..e98f0ed5 100644
--- a/backend/tests/test_registry.py
+++ b/backend/tests/test_registry.py
@@ -240,11 +240,12 @@ def test_update_preserves_builtin_source_type(app, plugin_dirs, monkeypatch):
 # --------------------------------------------------------------------------- #
 
 def test_registry_url_defaults_to_public_index(monkeypatch):
-    """Unset env → the curated serverkit-extensions raw index (the go-live
-    default). conftest pins it EMPTY suite-wide, so simulate unset here."""
+    """Unset env → the curated index via serverkit.ai (the go-live default;
+    it proxies the raw serverkit-extensions index with caching + logo URL
+    rewriting). conftest pins it EMPTY suite-wide, so simulate unset here."""
     monkeypatch.delenv('SERVERKIT_REGISTRY_URL', raising=False)
     assert registry_service._registry_url() == registry_service.DEFAULT_REGISTRY_URL
-    assert 'serverkit-extensions' in registry_service.DEFAULT_REGISTRY_URL
+    assert registry_service.DEFAULT_REGISTRY_URL == 'https://serverkit.ai/ext/index.json'
 
 
 def test_registry_url_empty_disables_remote(monkeypatch):
@@ -279,13 +280,20 @@ def test_v2_entry_normalizes_logo_and_repo():
 
 def test_relative_logo_resolved_against_index_base():
     """A repo-relative logo becomes absolute against the index URL it came
-    from (raw-GitHub index → raw asset URL)."""
-    base = registry_service.DEFAULT_REGISTRY_URL  # .../main/index.json
-    e = registry_service._normalize({
+    from (serverkit.ai index → /ext/assets URL; raw-GitHub index → raw asset
+    URL when used as a manual fallback)."""
+    entry = {
         'slug': 'gui', 'display_name': 'GUI', 'version': '1.0.0',
         'source': 'https://x/gui.zip',
         'logo': 'assets/gui/logo.svg',
-    }, base_url=base)
+    }
+    e = registry_service._normalize(
+        entry, base_url=registry_service.DEFAULT_REGISTRY_URL)
+    assert e['logo'] == 'https://serverkit.ai/ext/assets/gui/logo.svg'
+
+    e = registry_service._normalize(
+        entry,
+        base_url='https://raw.githubusercontent.com/jhd3197/serverkit-extensions/main/index.json')
     assert e['logo'] == (
         'https://raw.githubusercontent.com/jhd3197/serverkit-extensions/'
         'main/assets/gui/logo.svg'
diff --git a/docs/EXTENSIONS_REGISTRY.md b/docs/EXTENSIONS_REGISTRY.md
index 3516ecd3..29c91b1d 100644
--- a/docs/EXTENSIONS_REGISTRY.md
+++ b/docs/EXTENSIONS_REGISTRY.md
@@ -12,9 +12,10 @@ This document is the format spec (task #16) and the publisher guide (task #21).
 ## How a panel consumes the registry
 
 - The panel fetches the index from `SERVERKIT_REGISTRY_URL` (env var). When unset
-  it defaults to the curated public registry
-  (`https://raw.githubusercontent.com/jhd3197/serverkit-extensions/main/index.json`);
-  set it **empty** to disable remote fetching entirely (air-gapped panels). When
+  it defaults to the curated public registry via serverkit.ai
+  (`https://serverkit.ai/ext/index.json`, which proxies and caches the raw
+  `serverkit-extensions` index and serves its logo art); set it **empty** to
+  disable remote fetching entirely (air-gapped panels). When
   the fetch fails (offline), it falls back to the **last good cache**, then to a
   **bundled copy** shipped at `backend/app/data/registry_index.json`. The
   Marketplace never blanks.