diff --git a/src/VCS/Adapter/Git/GitLab.php b/src/VCS/Adapter/Git/GitLab.php
index 0cadaeeb..0a133d79 100644
--- a/src/VCS/Adapter/Git/GitLab.php
+++ b/src/VCS/Adapter/Git/GitLab.php
@@ -255,6 +255,45 @@ public function getInstallationRepository(string $repositoryName): array
         throw new Exception("getInstallationRepository is not applicable for this adapter");
     }
 
+    /**
+     * List namespaces the current user can browse: their personal namespace
+     * plus every group they belong to. GitLab's own /namespaces endpoint
+     * already combines both with correct pagination, so this is a thin
+     * passthrough rather than a hand-rolled merge of /user + /groups.
+     *
+     * @return array{items: array<array{id: string, name: string, path: string, kind: string, avatarUrl: string}>, total: int}
+     */
+    public function listNamespaces(int $page, int $per_page, string $search = ''): array
+    {
+        $url = "/namespaces?page={$page}&per_page={$per_page}";
+        if (!empty($search)) {
+            $url .= '&search=' . urlencode($search);
+        }
+
+        $response = $this->call(self::METHOD_GET, $url, ['Authorization' => 'Bearer ' . $this->accessToken]);
+        $responseHeaders = $response['headers'] ?? [];
+        $statusCode = $responseHeaders['status-code'] ?? 0;
+        if ($statusCode >= 400) {
+            throw new Exception("Failed to list namespaces: HTTP {$statusCode}", $statusCode);
+        }
+
+        $items = $response['body'] ?? [];
+        $items = is_array($items) ? $items : [];
+
+        $namespaces = array_map(fn (array $namespace) => [
+            'id' => (string) ($namespace['id'] ?? ''),
+            'name' => $namespace['name'] ?? ($namespace['path'] ?? ''),
+            'path' => $namespace['full_path'] ?? ($namespace['path'] ?? ''),
+            'kind' => $namespace['kind'] ?? 'group',
+            'avatarUrl' => $namespace['avatar_url'] ?? '',
+        ], $items);
+
+        return [
+            'items' => $namespaces,
+            'total' => (int) ($responseHeaders['x-total'] ?? \count($namespaces)),
+        ];
+    }
+
     public function searchRepositories(string $owner, int $page, int $per_page, string $search = ''): array
     {
         $ownerPath = $this->getOwnerPath($owner);
diff --git a/tests/VCS/Adapter/GitLabTest.php b/tests/VCS/Adapter/GitLabTest.php
index 3eba2ad5..f9504765 100644
--- a/tests/VCS/Adapter/GitLabTest.php
+++ b/tests/VCS/Adapter/GitLabTest.php
@@ -208,6 +208,44 @@ public function testGetOwnerNameWithRepositoryId(): void
         }
     }
 
+    public function testListNamespaces(): void
+    {
+        /** @var GitLab $adapter */
+        $adapter = $this->vcsAdapter;
+
+        $result = $adapter->listNamespaces(1, 20);
+
+        $this->assertIsArray($result);
+        $this->assertArrayHasKey('items', $result);
+        $this->assertArrayHasKey('total', $result);
+        $this->assertNotEmpty($result['items']);
+
+        $kinds = array_column($result['items'], 'kind');
+        $this->assertContains('user', $kinds);
+        $this->assertContains('group', $kinds);
+
+        foreach ($result['items'] as $namespace) {
+            $this->assertArrayHasKey('id', $namespace);
+            $this->assertArrayHasKey('name', $namespace);
+            $this->assertArrayHasKey('path', $namespace);
+            $this->assertArrayHasKey('kind', $namespace);
+            $this->assertNotEmpty($namespace['path']);
+        }
+    }
+
+    public function testListNamespacesWithSearch(): void
+    {
+        /** @var GitLab $adapter */
+        $adapter = $this->vcsAdapter;
+        $ownerPath = explode(':', static::$owner)[1] ?? static::$owner;
+
+        $result = $adapter->listNamespaces(1, 20, $ownerPath);
+
+        $this->assertNotEmpty($result['items']);
+        $paths = array_column($result['items'], 'path');
+        $this->assertContains($ownerPath, $paths);
+    }
+
     public function testSearchRepositories(): void
     {
         $repositoryName = 'test-search-repositories-' . \uniqid();