diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index 5cfb9e8..2581f43 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -12,6 +12,8 @@ on:
 env:
   DENSE_UPSTASH_VECTOR_REST_URL: ${{ secrets.DENSE_UPSTASH_VECTOR_REST_URL }}
   DENSE_UPSTASH_VECTOR_REST_TOKEN: ${{ secrets.DENSE_UPSTASH_VECTOR_REST_TOKEN }}
+  DENSE_EMBEDDING_UPSTASH_VECTOR_REST_URL: ${{ secrets.DENSE_EMBEDDING_UPSTASH_VECTOR_REST_URL }}
+  DENSE_EMBEDDING_UPSTASH_VECTOR_REST_TOKEN: ${{ secrets.DENSE_EMBEDDING_UPSTASH_VECTOR_REST_TOKEN }}
 
 jobs:
   test:
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index e6af434..3fd68a8 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -43,7 +43,11 @@
         </include>
     </source>
     <php>
+        <!-- For testing dense index -->
         <env name="DENSE_UPSTASH_VECTOR_REST_URL" value="https://vector.upstash.com" />
         <env name="DENSE_UPSTASH_VECTOR_REST_TOKEN" value="test-token" />
+        <!-- For testing dense index with embedding -->
+        <env name="DENSE_EMBEDDING_UPSTASH_VECTOR_REST_URL" value="https://vector.upstash.com" />
+        <env name="DENSE_EMBEDDING_UPSTASH_VECTOR_REST_TOKEN" value="test-token" />
     </php>
 </phpunit>
diff --git a/tests/Concerns/UsesDenseIndexWithEmbedding.php b/tests/Concerns/UsesDenseIndexWithEmbedding.php
new file mode 100644
index 0000000..dc00022
--- /dev/null
+++ b/tests/Concerns/UsesDenseIndexWithEmbedding.php
@@ -0,0 +1,33 @@
+<?php
+
+namespace Upstash\Vector\Tests\Concerns;
+
+use Upstash\Vector\Contracts\IndexInterface;
+use Upstash\Vector\Contracts\IndexNamespaceInterface;
+use Upstash\Vector\Index;
+
+trait UsesDenseIndexWithEmbedding
+{
+    protected IndexInterface $index;
+
+    protected IndexNamespaceInterface $namespace;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        $this->index = new Index(
+            url: getenv('DENSE_EMBEDDING_UPSTASH_VECTOR_REST_URL'),
+            token: getenv('DENSE_EMBEDDING_UPSTASH_VECTOR_REST_TOKEN'),
+        );
+
+        $this->namespace = $this->index->namespace(bin2hex(random_bytes(32)));
+    }
+
+    public function tearDown(): void
+    {
+        $this->namespace->delete();
+
+        parent::tearDown();
+    }
+}
diff --git a/tests/Dense/Operations/UpsertDataTest.php b/tests/Dense/Operations/UpsertDataTest.php
new file mode 100644
index 0000000..b04b7f5
--- /dev/null
+++ b/tests/Dense/Operations/UpsertDataTest.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace Upstash\Vector\Tests\Dense\Operations;
+
+use PHPUnit\Framework\TestCase;
+use Upstash\Vector\DataUpsert;
+use Upstash\Vector\Tests\Concerns\UsesDenseIndexWithEmbedding;
+use Upstash\Vector\Tests\Concerns\WaitsForIndex;
+
+class UpsertDataTest extends TestCase
+{
+    use UsesDenseIndexWithEmbedding;
+    use WaitsForIndex;
+
+    public function test_upsert_data(): void
+    {
+        $this->namespace->upsertData(new DataUpsert(
+            id: '1',
+            data: 'The capital of Japan is Tokyo',
+        ));
+
+        $this->waitForIndex($this->namespace);
+
+        $info = $this->namespace->getNamespaceInfo();
+
+        $this->assertSame(1, $info->vectorCount);
+    }
+
+    public function test_upsert_many_data(): void
+    {
+        $this->namespace->upsertDataMany([
+            new DataUpsert(id: '1', data: 'The capital of Japan is Tokyo'),
+            new DataUpsert(id: '2', data: 'The capital of France is Paris'),
+            new DataUpsert(id: '3', data: 'The capital of Germany is Berlin'),
+        ]);
+
+        $this->waitForIndex($this->namespace);
+
+        $info = $this->namespace->getNamespaceInfo();
+
+        $this->assertSame(3, $info->vectorCount);
+    }
+}