diff --git a/flint/flint-core/src/main/scala/org/opensearch/flint/core/FlintClient.java b/flint/flint-core/src/main/scala/org/opensearch/flint/core/FlintClient.java
index 3917f2855f..0b780d0de9 100644
--- a/flint/flint-core/src/main/scala/org/opensearch/flint/core/FlintClient.java
+++ b/flint/flint-core/src/main/scala/org/opensearch/flint/core/FlintClient.java
@@ -21,6 +21,14 @@ public interface FlintClient {
    */
   void createIndex(String indexName, FlintMetadata metadata);
 
+  /**
+   * Does Flint index with the given name exist
+   *
+   * @param indexName index name
+   * @return true if the index exists, otherwise false
+   */
+  boolean exists(String indexName);
+
   /**
    * Retrieve metadata in a Flint index.
    *
diff --git a/flint/flint-core/src/main/scala/org/opensearch/flint/core/storage/FlintOpenSearchClient.java b/flint/flint-core/src/main/scala/org/opensearch/flint/core/storage/FlintOpenSearchClient.java
index 851c1bfb48..c4c53178c9 100644
--- a/flint/flint-core/src/main/scala/org/opensearch/flint/core/storage/FlintOpenSearchClient.java
+++ b/flint/flint-core/src/main/scala/org/opensearch/flint/core/storage/FlintOpenSearchClient.java
@@ -13,6 +13,7 @@
 import org.opensearch.client.RestClient;
 import org.opensearch.client.RestHighLevelClient;
 import org.opensearch.client.indices.CreateIndexRequest;
+import org.opensearch.client.indices.GetIndexRequest;
 import org.opensearch.client.indices.GetMappingsRequest;
 import org.opensearch.client.indices.GetMappingsResponse;
 import org.opensearch.cluster.metadata.MappingMetadata;
@@ -42,7 +43,18 @@ public void createIndex(String indexName, FlintMetadata metadata) {
       request.mapping(buildIndexMapping(metadata));
 
       client.indices().create(request, RequestOptions.DEFAULT);
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to create Flint index", e);
+    }
+  }
+
+  @Override
+  public boolean exists(String indexName) {
+    try (RestHighLevelClient client = createClient()) {
+      return client.indices()
+          .exists(new GetIndexRequest(indexName), RequestOptions.DEFAULT);
     } catch (IOException e) {
+      throw new IllegalStateException("Failed to check if Flint index exists", e);
     }
   }
 
@@ -50,11 +62,12 @@ public void createIndex(String indexName, FlintMetadata metadata) {
   public FlintMetadata getIndexMetadata(String indexName) {
     try (RestHighLevelClient client = createClient()) {
       GetMappingsRequest request = new GetMappingsRequest().indices(indexName);
-      GetMappingsResponse response = client.indices().getMapping(request, RequestOptions.DEFAULT);
+      GetMappingsResponse response =
+          client.indices().getMapping(request, RequestOptions.DEFAULT);
 
       return parseIndexMapping(response.mappings().get(indexName));
-    } catch (IOException e) {
-      return null;
+    } catch (Exception e) {
+      throw new IllegalStateException("Failed to get Flint index metadata", e);
     }
   }
 
@@ -64,11 +77,13 @@ private RestHighLevelClient createClient() {
   }
 
   private Map<String, Object> buildIndexMapping(FlintMetadata metadata) {
+    // Convert from {"field": "int"} to {"field": {"type": "int"}}
     Map<String, Object> fieldTypes =
         metadata.getSchema().entrySet().stream()
             .collect(Collectors.toMap(
                 Map.Entry::getKey,
                 entry -> Map.of("type", entry.getValue())));
+
     return Map.of(
         "properties", fieldTypes,
         "_meta", metadata.getMeta());
@@ -77,6 +92,8 @@ private Map<String, Object> buildIndexMapping(FlintMetadata metadata) {
   @SuppressWarnings("unchecked")
   private FlintMetadata parseIndexMapping(MappingMetadata mapping) {
     Map<String, Object> source = mapping.getSourceAsMap();
+
+    // Parse {"field": {"type": "int"}} to {"field": "int"}
     Map<String, String> schema =
         ((Map<String, Object>) source.get("properties"))
             .entrySet().stream()
@@ -84,7 +101,6 @@ private FlintMetadata parseIndexMapping(MappingMetadata mapping) {
                 Map.Entry::getKey,
                 entry -> ((Map<String, String>) entry.getValue()).get("type")));
 
-    return new FlintMetadata(schema,
-        (Map<String, Object>) source.get("_meta"));
+    return new FlintMetadata(schema, (Map<String, Object>) source.get("_meta"));
   }
 }
diff --git a/flint/integ-test/src/test/scala/org/opensearch/flint/core/FlintOpenSearchClientSuite.scala b/flint/integ-test/src/test/scala/org/opensearch/flint/core/FlintOpenSearchClientSuite.scala
index 18e4863699..fe2ca14f5c 100644
--- a/flint/integ-test/src/test/scala/org/opensearch/flint/core/FlintOpenSearchClientSuite.scala
+++ b/flint/integ-test/src/test/scala/org/opensearch/flint/core/FlintOpenSearchClientSuite.scala
@@ -9,26 +9,36 @@ import org.opensearch.flint.OpenSearchSuite
 import org.opensearch.flint.core.metadata.FlintMetadata
 import org.opensearch.flint.core.storage.FlintOpenSearchClient
 import org.scalatest.flatspec.AnyFlatSpec
-import org.scalatest.matchers.should.Matchers.convertToAnyShouldWrapper
+import org.scalatest.matchers.should.Matchers
 
 import scala.collection.JavaConverters._
 
 class FlintOpenSearchClientSuite
     extends AnyFlatSpec
-    with OpenSearchSuite {
+    with OpenSearchSuite
+    with Matchers {
 
+  /** Lazy initialize after container started. */
   lazy val flintClient = new FlintOpenSearchClient(openSearchHost, openSearchPort)
 
+  behavior of "Flint OpenSearch client"
+
   it should "create index successfully" in {
+    val indexName = "test"
     val schema = Map("age" -> "integer").asJava
     val meta =
       Map("index" ->
         Map("kind" -> "SkippingIndex").asJava.asInstanceOf[Object]
       ).asJava
-    flintClient.createIndex("test", new FlintMetadata(schema, meta))
+    flintClient.createIndex(indexName, new FlintMetadata(schema, meta))
+
+    flintClient.exists(indexName) shouldBe true
+    flintClient.getIndexMetadata(indexName) should have (
+      'schema (schema),
+      'meta (meta))
+  }
 
-    val metadata = flintClient.getIndexMetadata("test")
-    metadata.getSchema shouldBe schema
-    metadata.getMeta shouldBe meta
+  it should "return false if index not exist" in {
+    flintClient.exists("non-exist-index") shouldBe false
   }
 }