diff --git a/.github/workflows/run-tests.yml b/.github/workflows/run-tests.yml
index 6333ab2..15ffbaa 100644
--- a/.github/workflows/run-tests.yml
+++ b/.github/workflows/run-tests.yml
@@ -16,6 +16,8 @@ env:
   DENSE_EMBEDDING_UPSTASH_VECTOR_REST_TOKEN: ${{ secrets.DENSE_EMBEDDING_UPSTASH_VECTOR_REST_TOKEN }}
   SPARSE_UPSTASH_VECTOR_REST_URL: ${{ secrets.SPARSE_UPSTASH_VECTOR_REST_URL }}
   SPARSE_UPSTASH_VECTOR_REST_TOKEN: ${{ secrets.SPARSE_UPSTASH_VECTOR_REST_TOKEN }}
+  HYBRID_UPSTASH_VECTOR_REST_URL: ${{ secrets.HYBRID_UPSTASH_VECTOR_REST_URL }}
+  HYBRID_UPSTASH_VECTOR_REST_TOKEN: ${{ secrets.HYBRID_UPSTASH_VECTOR_REST_TOKEN }}
 
 jobs:
   test:
diff --git a/phpunit.xml.dist b/phpunit.xml.dist
index a81ea2a..92e9f88 100644
--- a/phpunit.xml.dist
+++ b/phpunit.xml.dist
@@ -52,5 +52,8 @@
         <!-- For testing sparse index -->
         <env name="SPARSE_UPSTASH_VECTOR_REST_URL" value="https://vector.upstash.com" />
         <env name="SPARSE_UPSTASH_VECTOR_REST_TOKEN" value="test-token" />
+        <!-- For testing hybrid index -->
+        <env name="HYBRID_UPSTASH_VECTOR_REST_URL" value="https://vector.upstash.com" />
+        <env name="HYBRID_UPSTASH_VECTOR_REST_TOKEN" value="test-token" />
     </php>
 </phpunit>
diff --git a/tests/Concerns/GeneratesVectors.php b/tests/Concerns/GeneratesVectors.php
index edaaebd..30651c6 100644
--- a/tests/Concerns/GeneratesVectors.php
+++ b/tests/Concerns/GeneratesVectors.php
@@ -2,4 +2,16 @@
 
 namespace Upstash\Vector\Tests\Concerns;
 
-trait GeneratesVectors {}
+trait GeneratesVectors
+{
+    protected function generateVector(int $dimensions): array
+    {
+        $vector = [];
+
+        for ($i = 0; $i < $dimensions; $i++) {
+            $vector[] = random_int(0, 100) / 100;
+        }
+
+        return $vector;
+    }
+}
diff --git a/tests/Concerns/UsesHybridIndex.php b/tests/Concerns/UsesHybridIndex.php
new file mode 100644
index 0000000..2cae894
--- /dev/null
+++ b/tests/Concerns/UsesHybridIndex.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 UsesHybridIndex
+{
+    protected IndexInterface $index;
+
+    protected IndexNamespaceInterface $namespace;
+
+    public function setUp(): void
+    {
+        parent::setUp();
+
+        $this->index = new Index(
+            url: getenv('HYBRID_UPSTASH_VECTOR_REST_URL'),
+            token: getenv('HYBRID_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/Hybrid/Operations/QueryDataTest.php b/tests/Hybrid/Operations/QueryDataTest.php
new file mode 100644
index 0000000..a940e21
--- /dev/null
+++ b/tests/Hybrid/Operations/QueryDataTest.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace Upstash\Vector\Tests\Hybrid\Operations;
+
+use PHPUnit\Framework\TestCase;
+use Upstash\Vector\DataQuery;
+use Upstash\Vector\DataUpsert;
+use Upstash\Vector\Tests\Concerns\UsesHybridIndex;
+use Upstash\Vector\Tests\Concerns\WaitsForIndex;
+
+class QueryDataTest extends TestCase
+{
+    use UsesHybridIndex;
+    use WaitsForIndex;
+
+    public function test_query_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);
+
+        $results = $this->namespace->queryData(new DataQuery(
+            data: 'capital of France',
+            topK: 1,
+        ));
+
+        $this->assertCount(1, $results);
+        $this->assertEquals('2', $results[0]->id);
+    }
+}
diff --git a/tests/Hybrid/Operations/QueryVectorsTest.php b/tests/Hybrid/Operations/QueryVectorsTest.php
new file mode 100644
index 0000000..b1f74d6
--- /dev/null
+++ b/tests/Hybrid/Operations/QueryVectorsTest.php
@@ -0,0 +1,95 @@
+<?php
+
+namespace Upstash\Vector\Tests\Hybrid\Operations;
+
+use PHPUnit\Framework\TestCase;
+use Upstash\Vector\SparseVector;
+use Upstash\Vector\Tests\Concerns\GeneratesVectors;
+use Upstash\Vector\Tests\Concerns\UsesHybridIndex;
+use Upstash\Vector\Tests\Concerns\WaitsForIndex;
+use Upstash\Vector\VectorQuery;
+use Upstash\Vector\VectorUpsert;
+
+class QueryVectorsTest extends TestCase
+{
+    use GeneratesVectors;
+    use UsesHybridIndex;
+    use WaitsForIndex;
+
+    public function test_query_vectors(): void
+    {
+        $vector = $this->generateVector(384);
+
+        $this->namespace->upsert(new VectorUpsert(
+            id: '1',
+            vector: $vector,
+            sparseVector: new SparseVector(
+                indices: [1, 2, 3],
+                values: [5, 6, 7],
+            ),
+        ));
+
+        $this->waitForIndex($this->namespace);
+
+        $vectors = $this->namespace->query(new VectorQuery(
+            vector: $vector,
+            sparseVector: new SparseVector(
+                indices: [1, 2, 3],
+                values: [5, 6, 7],
+            ),
+            topK: 1,
+        ));
+
+        $this->assertCount(1, $vectors);
+        $this->assertSame('1', $vectors[0]->id);
+    }
+
+    public function test_query_with_no_vectors(): void
+    {
+        $this->namespace->upsert(new VectorUpsert(
+            id: '1',
+            vector: $this->generateVector(384),
+            sparseVector: new SparseVector(
+                indices: [1, 2, 3],
+                values: [5, 6, 7],
+            ),
+        ));
+
+        $this->waitForIndex($this->namespace);
+
+        $vectors = $this->namespace->query(new VectorQuery(
+            sparseVector: new SparseVector(
+                indices: [1, 2, 3],
+                values: [5, 6, 7],
+            ),
+            topK: 1,
+        ));
+
+        $this->assertCount(1, $vectors);
+        $this->assertSame('1', $vectors[0]->id);
+    }
+
+    public function test_query_with_no_sparse_vectors(): void
+    {
+        $vector = $this->generateVector(384);
+
+        $this->namespace->upsert(new VectorUpsert(
+            id: '1',
+            vector: $vector,
+            sparseVector: new SparseVector(
+                indices: [1, 2, 3],
+                values: [5, 6, 7],
+            ),
+        ));
+
+        $this->waitForIndex($this->namespace);
+
+        $vectors = $this->namespace->query(new VectorQuery(
+            vector: $vector,
+            topK: 1,
+        ));
+
+        $this->assertCount(1, $vectors);
+        $this->assertSame('1', $vectors[0]->id);
+    }
+}
diff --git a/tests/Hybrid/Operations/UpsertDataTest.php b/tests/Hybrid/Operations/UpsertDataTest.php
new file mode 100644
index 0000000..cac2708
--- /dev/null
+++ b/tests/Hybrid/Operations/UpsertDataTest.php
@@ -0,0 +1,43 @@
+<?php
+
+namespace Upstash\Vector\Tests\Hybrid\Operations;
+
+use PHPUnit\Framework\TestCase;
+use Upstash\Vector\DataUpsert;
+use Upstash\Vector\Tests\Concerns\UsesHybridIndex;
+use Upstash\Vector\Tests\Concerns\WaitsForIndex;
+
+class UpsertDataTest extends TestCase
+{
+    use UsesHybridIndex;
+    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);
+    }
+}
diff --git a/tests/Hybrid/Operations/UpsertVectorTest.php b/tests/Hybrid/Operations/UpsertVectorTest.php
new file mode 100644
index 0000000..3914475
--- /dev/null
+++ b/tests/Hybrid/Operations/UpsertVectorTest.php
@@ -0,0 +1,89 @@
+<?php
+
+namespace Upstash\Vector\Tests\Hybrid\Operations;
+
+use PHPUnit\Framework\TestCase;
+use Upstash\Vector\Exceptions\OperationFailedException;
+use Upstash\Vector\SparseVector;
+use Upstash\Vector\Tests\Concerns\GeneratesVectors;
+use Upstash\Vector\Tests\Concerns\UsesHybridIndex;
+use Upstash\Vector\Tests\Concerns\WaitsForIndex;
+use Upstash\Vector\VectorUpsert;
+
+class UpsertVectorTest extends TestCase
+{
+    use GeneratesVectors;
+    use UsesHybridIndex;
+    use WaitsForIndex;
+
+    public function test_upsert_vector(): void
+    {
+        $this->namespace->upsert(new VectorUpsert(
+            id: '1',
+            vector: $this->generateVector(384),
+            sparseVector: new SparseVector(
+                indices: [1, 2, 3],
+                values: [5, 6, 7],
+            ),
+        ));
+
+        $this->waitForIndex($this->namespace);
+
+        $info = $this->namespace->getNamespaceInfo();
+
+        $this->assertSame(1, $info->vectorCount);
+    }
+
+    public function test_upsert_without_sparse_vector_throws_exception(): void
+    {
+        $this->expectException(OperationFailedException::class);
+        $this->expectExceptionMessage('This index requires sparse vectors');
+
+        $this->namespace->upsert(new VectorUpsert(
+            id: '1',
+            vector: $this->generateVector(384),
+        ));
+    }
+
+    public function test_upsert_without_vector_throws_exception(): void
+    {
+        $this->expectException(OperationFailedException::class);
+        $this->expectExceptionMessage('This index requires dense vectors');
+
+        $this->namespace->upsert(new VectorUpsert(
+            id: '1',
+            sparseVector: new SparseVector(
+                indices: [1, 2, 3],
+                values: [5, 6, 7],
+            ),
+        ));
+    }
+
+    public function test_upsert_many_vectors(): void
+    {
+        $this->namespace->upsertMany([
+            new VectorUpsert(
+                id: '1',
+                vector: $this->generateVector(384),
+                sparseVector: new SparseVector(
+                    indices: [1, 2, 3],
+                    values: [5, 6, 7],
+                ),
+            ),
+            new VectorUpsert(
+                id: '2',
+                vector: $this->generateVector(384),
+                sparseVector: new SparseVector(
+                    indices: [4, 5, 6],
+                    values: [8, 9, 10],
+                ),
+            ),
+        ]);
+
+        $this->waitForIndex($this->namespace);
+
+        $info = $this->namespace->getNamespaceInfo();
+
+        $this->assertSame(2, $info->vectorCount);
+    }
+}