diff --git a/src/IO.Milvus/ApiSchema/DescribeCollectionResponse.cs b/src/IO.Milvus/ApiSchema/DescribeCollectionResponse.cs
index 1b2115f..0669c03 100644
--- a/src/IO.Milvus/ApiSchema/DescribeCollectionResponse.cs
+++ b/src/IO.Milvus/ApiSchema/DescribeCollectionResponse.cs
@@ -1,4 +1,5 @@
-using IO.Milvus.Utils;
+using System;
+using IO.Milvus.Utils;
 using System.Collections.Generic;
 using System.Text.Json.Serialization;
 
@@ -75,14 +76,13 @@ internal sealed class DescribeCollectionResponse
     public DetailedMilvusCollection ToDetailedMilvusCollection()
     {
         return new DetailedMilvusCollection(
-            Aliases,
+            (IReadOnlyList<string>)Aliases ?? Array.Empty<string>(),
             CollectionName,
             CollectionId,
             ConsistencyLevel,
             TimestampUtils.GetTimeFromTimstamp(CreatedUTCTimestamp),
             Schema,
             ShardsNum,
-            StartPositions
-            );
+            StartPositions);
     }
 }
diff --git a/src/IO.MilvusTests/Client/AliasTests.cs b/src/IO.MilvusTests/Client/AliasTests.cs
new file mode 100644
index 0000000..c6f5747
--- /dev/null
+++ b/src/IO.MilvusTests/Client/AliasTests.cs
@@ -0,0 +1,85 @@
+using IO.Milvus;
+using IO.Milvus.Client;
+using IO.Milvus.Client.gRPC;
+using Xunit;
+
+namespace IO.MilvusTests.Client;
+
+public class AliasTests : IAsyncLifetime
+{
+    [Theory]
+    [ClassData(typeof(TestClients))]
+    public async Task Create(IMilvusClient client)
+    {
+        await client.DropAliasAsync("a");
+        await client.DropAliasAsync("b");
+
+        await client.CreateAliasAsync(CollectionName, "a");
+        await client.CreateAliasAsync(CollectionName, "b");
+
+        var description = await client.DescribeCollectionAsync(CollectionName);
+        Assert.Collection(description.Aliases.Order(),
+            alias => Assert.Equal("a", alias),
+            alias => Assert.Equal("b", alias));
+    }
+
+    [Theory]
+    [ClassData(typeof(TestClients))]
+    public async Task Alter(IMilvusClient client)
+    {
+        await client.DropAliasAsync("a");
+        await client.CreateAliasAsync(CollectionName, "a");
+
+        await client.DropCollectionAsync("AnotherCollection");
+        await client.CreateCollectionAsync(
+            "AnotherCollection",
+            new[] { FieldType.Create<long>("id", isPrimaryKey: true) });
+
+        await client.AlterAliasAsync("AnotherCollection", "a");
+
+        var description1 = await client.DescribeCollectionAsync(CollectionName);
+        Assert.DoesNotContain(description1.Aliases, alias => alias == "a");
+
+        var description2 = await client.DescribeCollectionAsync("AnotherCollection");
+        Assert.Collection(description2.Aliases, alias => Assert.Equal("a", alias));
+    }
+
+    [Theory]
+    [ClassData(typeof(TestClients))]
+    public async Task Drop(IMilvusClient client)
+    {
+        await client.DropAliasAsync("a");
+        await client.CreateAliasAsync(CollectionName, "a");
+
+        await client.DropAliasAsync("a");
+
+        var description = await client.DescribeCollectionAsync(CollectionName);
+        Assert.DoesNotContain(description.Aliases, alias => alias == "a");
+    }
+
+    public string CollectionName => nameof(AliasTests);
+
+    public async Task InitializeAsync()
+    {
+        var config = MilvusConfig.Load().FirstOrDefault();
+        if (config is null)
+        {
+            throw new InvalidOperationException("No client configs");
+        }
+
+        var client = config.CreateClient();
+
+        await client.DropCollectionAsync(CollectionName);
+        await client.CreateCollectionAsync(
+            CollectionName,
+            new[]
+            {
+                FieldType.Create<long>("id", isPrimaryKey: true),
+                FieldType.CreateVarchar("varchar", 256),
+                FieldType.CreateFloatVector("float_vector", 2)
+            });
+    }
+
+    public Task DisposeAsync()
+        => Task.CompletedTask;
+}
diff --git a/src/IO.MilvusTests/Client/QueryTests.cs b/src/IO.MilvusTests/Client/QueryTests.cs
index 6a6c542..fbad25a 100644
--- a/src/IO.MilvusTests/Client/QueryTests.cs
+++ b/src/IO.MilvusTests/Client/QueryTests.cs
@@ -4,7 +4,7 @@
 
 namespace IO.MilvusTests.Client;
 
-public class QueryTests : IClassFixture<QueryCollectionFixture>
+public class QueryTests : IClassFixture<QueryTests.QueryCollectionFixture>
 {
     private string QueryCollectionName { get; }
 
@@ -41,6 +41,21 @@ public async Task Query(IMilvusClient client)
             v => Assert.Equal(new List<float> { 5f, 6f }, v));
     }
 
+    [Theory(Skip = "Fails")]
+    [ClassData(typeof(TestClients))]
+    public async Task Query_with_offset(IMilvusClient client)
+    {
+        var queryResult = await client.QueryAsync(
+            QueryCollectionName,
+            "id in [2, 3]",
+            outputFields: new[] { "float_vector" },
+            offset: 1);
+
+        var idData = (Field<long>)Assert.Single(queryResult.FieldsData, d => d.FieldName == "id");
+        Assert.Equal(1, idData.RowCount);
+        Assert.Collection(idData.Data, id => Assert.Equal(3, id));
+    }
+
     [Theory]
     [ClassData(typeof(TestClients))]
     public async Task Query_with_limit(IMilvusClient client)
@@ -55,59 +70,59 @@ public async Task Query_with_limit(IMilvusClient client)
         Assert.Equal(1, idData.RowCount);
         Assert.Collection(idData.Data, id => Assert.Equal(2, id));
     }
-}
-
-public class QueryCollectionFixture : IAsyncLifetime
-{
-    public string CollectionName => "QueryCollection";
 
-    public async Task InitializeAsync()
+    public class QueryCollectionFixture : IAsyncLifetime
     {
-        var config = MilvusConfig.Load().FirstOrDefault();
-        if (config is null)
-        {
-            throw new InvalidOperationException("No client configs");
-        }
+        public string CollectionName => "QueryCollection";
 
-        var client = config.CreateClient();
-
-        await client.DropCollectionAsync(CollectionName);
-        await client.CreateCollectionAsync(
-            CollectionName,
-            new[]
-            {
-                FieldType.Create<long>("id", isPrimaryKey: true),
-                FieldType.CreateVarchar("varchar", 256),
-                FieldType.CreateFloatVector("float_vector", 2)
-            });
-
-        var ids = new long[] { 1, 2, 3, 4, 5 };
-        var strings = new[] { "one", "two", "three", "four", "five" };
-        var floatVectors = new[]
+        public async Task InitializeAsync()
         {
-            new List<float> { 1f, 2f },
-            new List<float> { 3.5f, 4.5f },
-            new List<float> { 5f, 6f },
-            new List<float> { 7.7f, 8.8f },
-            new List<float> { 9f, 10f }
-        };
-
-        await client.CreateIndexAsync(
-            CollectionName, "float_vector", "float_vector_idx", MilvusIndexType.FLAT, MilvusMetricType.L2);
-
-        await client.InsertAsync(
-            CollectionName,
-            new Field[]
+            var config = MilvusConfig.Load().FirstOrDefault();
+            if (config is null)
+            {
+                throw new InvalidOperationException("No client configs");
+            }
+
+            var client = config.CreateClient();
+
+            await client.DropCollectionAsync(CollectionName);
+            await client.CreateCollectionAsync(
+                CollectionName,
+                new[]
+                {
+                    FieldType.Create<long>("id", isPrimaryKey: true),
+                    FieldType.CreateVarchar("varchar", 256),
+                    FieldType.CreateFloatVector("float_vector", 2)
+                });
+
+            await client.CreateIndexAsync(
+                CollectionName, "float_vector", "float_vector_idx", MilvusIndexType.FLAT, MilvusMetricType.L2);
+
+            var ids = new long[] { 1, 2, 3, 4, 5 };
+            var strings = new[] { "one", "two", "three", "four", "five" };
+            var floatVectors = new[]
             {
-                Field.Create("id", ids),
-                Field.Create("varchar", strings),
-                Field.CreateFloatVector("float_vector", floatVectors)
-            });
+                new List<float> { 1f, 2f },
+                new List<float> { 3.5f, 4.5f },
+                new List<float> { 5f, 6f },
+                new List<float> { 7.7f, 8.8f },
+                new List<float> { 9f, 10f }
+            };
+
+            await client.InsertAsync(
+                CollectionName,
+                new Field[]
+                {
+                    Field.Create("id", ids),
+                    Field.Create("varchar", strings),
+                    Field.CreateFloatVector("float_vector", floatVectors)
+                });
+
+            await client.LoadCollectionAsync(CollectionName);
+            await client.WaitForLoadingProgressCollectionAsync(CollectionName, Array.Empty<string>(), TimeSpan.FromMilliseconds(100), TimeSpan.FromMinutes(1));
+        }
 
-        await client.LoadCollectionAsync(CollectionName);
-        await client.WaitForLoadingProgressCollectionAsync(CollectionName, Array.Empty<string>(), TimeSpan.FromMilliseconds(100), TimeSpan.FromMinutes(1));
+        public Task DisposeAsync()
+            => Task.CompletedTask;
     }
-
-    public Task DisposeAsync()
-        => Task.CompletedTask;
 }