diff --git a/src/OllamaSharp/MicrosoftAi/AbstractionMapper.cs b/src/OllamaSharp/MicrosoftAi/AbstractionMapper.cs
index d6fe530..7f50246 100644
--- a/src/OllamaSharp/MicrosoftAi/AbstractionMapper.cs
+++ b/src/OllamaSharp/MicrosoftAi/AbstractionMapper.cs
@@ -31,8 +31,10 @@ internal static class AbstractionMapper
 		if (stream is null)
 			return null;
 
+		var responseId = stream.CreatedAtString ?? Guid.NewGuid().ToString("N");
 		var chatMessage = ToChatMessage(stream.Message);
 		chatMessage.CreatedAt = stream.CreatedAt;
+		chatMessage.MessageId = responseId;
 
 		return new ChatResponse(chatMessage)
 		{
@@ -41,7 +43,7 @@ internal static class AbstractionMapper
 			CreatedAt = stream.CreatedAt,
 			ModelId = usedModel ?? stream.Model,
 			RawRepresentation = stream,
-			ResponseId = stream.CreatedAtString ?? Guid.NewGuid().ToString("N"),
+			ResponseId = responseId,
 			Usage = ParseOllamaChatResponseUsage(stream)
 		};
 	}
@@ -348,6 +350,7 @@ public static ChatResponseUpdate ToChatResponseUpdate(ChatResponseStream? respon
 				AdditionalProperties = ParseOllamaChatResponseProps(done),
 				CreatedAt = done.CreatedAt,
 				FinishReason = done.DoneReason is null ? null : new ChatFinishReason(done.DoneReason),
+				MessageId = responseId,
 				RawRepresentation = response,
 				ResponseId = responseId,
 				ModelId = done.Model
@@ -359,6 +362,7 @@ public static ChatResponseUpdate ToChatResponseUpdate(ChatResponseStream? respon
 			// no need to set "Contents" as we set the text
 			CreatedAt = response?.CreatedAt,
 			FinishReason = response?.Done == true ? ChatFinishReason.Stop : null,
+			MessageId = responseId,
 			RawRepresentation = response,
 			ResponseId = responseId,
 			ModelId = response?.Model
diff --git a/test/AbstractionMapperTests.cs b/test/AbstractionMapperTests.cs
index 13dca23..02c6ae0 100644
--- a/test/AbstractionMapperTests.cs
+++ b/test/AbstractionMapperTests.cs
@@ -930,6 +930,7 @@ public void Maps_Known_Properties()
 			response.CreatedAt.ShouldBe(new DateTimeOffset(2023, 08, 04, 08, 52, 19, 385, 406, TimeSpan.FromHours(-7)));
 			response.FinishReason.ShouldBe(ChatFinishReason.Stop);
 			response.Messages[0].AuthorName.ShouldBeNull();
+			response.Messages[0].MessageId.ShouldBe(ollamaCreatedStamp);
 			response.Messages[0].RawRepresentation.ShouldBe(stream.Message);
 			response.Messages[0].Role.ShouldBe(Microsoft.Extensions.AI.ChatRole.Assistant);
 			response.Messages[0].Text.ShouldBe("Hi.");
@@ -974,6 +975,7 @@ public void Maps_Known_Properties()
 			((TextContent)streamingChatCompletion.Contents[0]).Text.ShouldBe("Hi.");
 			streamingChatCompletion.CreatedAt.ShouldBe(new DateTimeOffset(2023, 08, 04, 08, 52, 19, 385, 406, TimeSpan.FromHours(-7)));
 			streamingChatCompletion.FinishReason.ShouldBe(ChatFinishReason.Stop);
+			streamingChatCompletion.MessageId.ShouldBe("12345");
 			streamingChatCompletion.RawRepresentation.ShouldBe(stream);
 			streamingChatCompletion.ResponseId.ShouldBe("12345");
 			streamingChatCompletion.Role.ShouldBe(Microsoft.Extensions.AI.ChatRole.Assistant);
@@ -1004,6 +1006,7 @@ public void Maps_Thinking_Tokens()
 			((TextReasoningContent)streamingChatCompletion.Contents[0]).Text.ShouldBe("Beer.");
 			streamingChatCompletion.CreatedAt.ShouldBe(new DateTimeOffset(2023, 08, 04, 08, 52, 19, 385, 406, TimeSpan.FromHours(-7)));
 			streamingChatCompletion.FinishReason.ShouldBe(ChatFinishReason.Stop);
+			streamingChatCompletion.MessageId.ShouldBe("12345");
 			streamingChatCompletion.RawRepresentation.ShouldBe(stream);
 			streamingChatCompletion.ResponseId.ShouldBe("12345");
 			streamingChatCompletion.Role.ShouldBe(Microsoft.Extensions.AI.ChatRole.Assistant);
@@ -1068,6 +1071,58 @@ public void Maps_ToolCalls()
 			chatMessage.Text.ShouldBe("It seems the sun will be out all day.");
 		}
 
+		/// <summary>
+		/// Verifies that MEAI keeps updates from separate provider calls in separate messages.
+		/// </summary>
+		[Test]
+		public void Separates_Updates_With_Different_MessageIds()
+		{
+			var updates = new[]
+			{
+				AbstractionMapper.ToChatResponseUpdate(new ChatResponseStream
+				{
+					Message = new Message { Role = OllamaSharp.Models.Chat.ChatRole.Assistant, Content = "First" }
+				}, "response-1"),
+				AbstractionMapper.ToChatResponseUpdate(new ChatResponseStream
+				{
+					Message = new Message { Role = OllamaSharp.Models.Chat.ChatRole.Assistant, Content = "Second" }
+				}, "response-2")
+			};
+
+			var response = updates.ToChatResponse();
+
+			response.Messages.Count.ShouldBe(2);
+			response.Messages[0].MessageId.ShouldBe("response-1");
+			response.Messages[0].Text.ShouldBe("First");
+			response.Messages[1].MessageId.ShouldBe("response-2");
+			response.Messages[1].Text.ShouldBe("Second");
+		}
+
+		/// <summary>
+		/// Verifies that MEAI combines chunks that belong to the same logical message.
+		/// </summary>
+		[Test]
+		public void Combines_Updates_With_The_Same_MessageId()
+		{
+			var updates = new[]
+			{
+				AbstractionMapper.ToChatResponseUpdate(new ChatResponseStream
+				{
+					Message = new Message { Role = OllamaSharp.Models.Chat.ChatRole.Assistant, Content = "Hel" }
+				}, "response-1"),
+				AbstractionMapper.ToChatResponseUpdate(new ChatResponseStream
+				{
+					Message = new Message { Role = OllamaSharp.Models.Chat.ChatRole.Assistant, Content = "lo" }
+				}, "response-1")
+			};
+
+			var response = updates.ToChatResponse();
+
+			response.Messages.Count.ShouldBe(1);
+			response.Messages[0].MessageId.ShouldBe("response-1");
+			response.Messages[0].Text.ShouldBe("Hello");
+		}
+
 		/// <summary>
 		/// Verifies that performance metrics from ChatDoneResponseStream (LoadDuration, TotalDuration, etc.) 
 		/// are correctly mapped to the AdditionalProperties dictionary.
@@ -1107,6 +1162,7 @@ public void Maps_Performance_Metrics_To_AdditionalProperties()
 			// Assert - AdditionalProperties contains performance metrics
 			const double NANOSECONDS_PER_MILLISECOND = 1_000_000;
 
+			streamingChatCompletion.MessageId.ShouldBe(responseId);
 			streamingChatCompletion.AdditionalProperties.ShouldNotBeNull();
 			streamingChatCompletion.AdditionalProperties.ShouldContainKey(Application.LoadDuration);
 			streamingChatCompletion.AdditionalProperties[Application.LoadDuration].ShouldBe(TimeSpan.FromMilliseconds(123_456_789 / NANOSECONDS_PER_MILLISECOND));
@@ -1127,6 +1183,13 @@ public void Maps_Performance_Metrics_To_AdditionalProperties()
 			usageContent.Details.InputTokenCount.ShouldBe(42);
 			usageContent.Details.OutputTokenCount.ShouldBe(15);
 			usageContent.Details.TotalTokenCount.ShouldBe(42 + 15);
+
+			var combinedResponse = new[] { streamingChatCompletion }.ToChatResponse();
+			combinedResponse.Messages.Single().AdditionalProperties.ShouldNotBeNull();
+			combinedResponse.Messages.Single().AdditionalProperties.ShouldContainKey(Application.TotalDuration);
+			combinedResponse.Usage.ShouldNotBeNull();
+			combinedResponse.Usage.InputTokenCount.ShouldBe(42);
+			combinedResponse.Usage.OutputTokenCount.ShouldBe(15);
 		}
 	}
 }
@@ -1273,4 +1336,4 @@ public void Maps_Response()
 }
 
 #pragma warning restore CS8602 // Dereference of a possibly null reference.
-#pragma warning restore CS8604 // Possible null reference argument.
\ No newline at end of file
+#pragma warning restore CS8604 // Possible null reference argument.