diff --git a/src/vs/workbench/contrib/chat/test/common/__snapshots__/ChatService_can_deserialize_with_response.0.snap b/src/vs/workbench/contrib/chat/test/common/__snapshots__/ChatService_can_deserialize_with_response.0.snap
new file mode 100644
index 00000000000..08839ed2bf7
--- /dev/null
+++ b/src/vs/workbench/contrib/chat/test/common/__snapshots__/ChatService_can_deserialize_with_response.0.snap
@@ -0,0 +1,84 @@
+{
+  requesterUsername: "test",
+  requesterAvatarIconUri: undefined,
+  responderUsername: "",
+  responderAvatarIconUri: undefined,
+  initialLocation: "panel",
+  requests: [
+    {
+      message: {
+        text: "@ChatProviderWithUsedContext test request",
+        parts: [
+          {
+            range: {
+              start: 0,
+              endExclusive: 28
+            },
+            editorRange: {
+              startLineNumber: 1,
+              startColumn: 1,
+              endLineNumber: 1,
+              endColumn: 29
+            },
+            agent: {
+              name: "ChatProviderWithUsedContext",
+              id: "ChatProviderWithUsedContext",
+              extensionId: {
+                value: "nullExtensionDescription",
+                _lower: "nullextensiondescription"
+              },
+              extensionPublisherId: "",
+              publisherDisplayName: "",
+              extensionDisplayName: "",
+              locations: [ "panel" ],
+              metadata: {  },
+              slashCommands: [  ],
+              disambiguation: [  ]
+            },
+            kind: "agent"
+          },
+          {
+            range: {
+              start: 28,
+              endExclusive: 41
+            },
+            editorRange: {
+              startLineNumber: 1,
+              startColumn: 29,
+              endLineNumber: 1,
+              endColumn: 42
+            },
+            text: " test request",
+            kind: "text"
+          }
+        ]
+      },
+      variableData: { variables: [  ] },
+      response: [  ],
+      result: { errorDetails: { message: "No activated agent with id \"ChatProviderWithUsedContext\"" } },
+      followups: undefined,
+      isCanceled: false,
+      vote: undefined,
+      voteDownReason: undefined,
+      agent: {
+        name: "ChatProviderWithUsedContext",
+        id: "ChatProviderWithUsedContext",
+        extensionId: {
+          value: "nullExtensionDescription",
+          _lower: "nullextensiondescription"
+        },
+        extensionPublisherId: "",
+        publisherDisplayName: "",
+        extensionDisplayName: "",
+        locations: [ "panel" ],
+        metadata: {  },
+        slashCommands: [  ],
+        disambiguation: [  ]
+      },
+      slashCommand: undefined,
+      usedContext: undefined,
+      contentReferences: [  ],
+      codeCitations: [  ]
+    }
+  ]
+}
\ No newline at end of file
diff --git a/src/vs/workbench/contrib/chat/test/common/chatService.test.ts b/src/vs/workbench/contrib/chat/test/common/chatService.test.ts
index d4960113662..393c3813b83 100644
--- a/src/vs/workbench/contrib/chat/test/common/chatService.test.ts
+++ b/src/vs/workbench/contrib/chat/test/common/chatService.test.ts
@@ -33,6 +33,7 @@ import { NullWorkbenchAssignmentService } from '../../../../services/assignment/
 import { IExtensionService, nullExtensionDescription } from '../../../../services/extensions/common/extensions.js';
 import { IViewsService } from '../../../../services/views/common/viewsService.js';
 import { TestContextService, TestExtensionService, TestStorageService } from '../../../../test/common/workbenchTestServices.js';
+import { MarkdownString } from '../../../../../base/common/htmlContent.js';
 
 const chatAgentWithUsedContextId = 'ChatProviderWithUsedContext';
 const chatAgentWithUsedContext: IChatAgent = {
@@ -67,6 +68,27 @@ const chatAgentWithUsedContext: IChatAgent = {
 	},
 };
 
+const chatAgentWithMarkdownId = 'ChatProviderWithMarkdown';
+const chatAgentWithMarkdown: IChatAgent = {
+	id: chatAgentWithMarkdownId,
+	name: chatAgentWithMarkdownId,
+	extensionId: nullExtensionDescription.identifier,
+	publisherDisplayName: '',
+	extensionPublisherId: '',
+	extensionDisplayName: '',
+	locations: [ChatAgentLocation.Panel],
+	metadata: {},
+	slashCommands: [],
+	disambiguation: [],
+	async invoke(request, progress, history, token) {
+		progress({ kind: 'markdownContent', content: new MarkdownString('test') });
+		return { metadata: { metadataKey: 'value' } };
+	},
+	async provideFollowups(sessionId, token) {
+		return [];
+	},
+};
+
 function getAgentData(id: string) {
 	return {
 		name: id,
@@ -116,6 +138,7 @@ suite('ChatService', () => {
 		};
 		testDisposables.add(chatAgentService.registerAgent('testAgent', { ...getAgentData('testAgent'), isDefault: true }));
 		testDisposables.add(chatAgentService.registerAgent(chatAgentWithUsedContextId, getAgentData(chatAgentWithUsedContextId)));
+		testDisposables.add(chatAgentService.registerAgent(chatAgentWithMarkdownId, getAgentData(chatAgentWithMarkdownId)));
 		testDisposables.add(chatAgentService.registerAgentImplementation('testAgent', agent));
 		chatAgentService.updateAgent('testAgent', { requester: { name: 'test' } });
 	});
@@ -253,4 +276,32 @@ suite('ChatService', () => {
 
 		await assertSnapshot(chatModel2.toExport());
 	});
+
+	test('can deserialize with response', async () => {
+		let serializedChatData: ISerializableChatData;
+		testDisposables.add(chatAgentService.registerAgentImplementation(chatAgentWithMarkdownId, chatAgentWithMarkdown));
+
+		{
+			const testService = testDisposables.add(instantiationService.createInstance(ChatService));
+
+			const chatModel1 = testDisposables.add(testService.startSession(ChatAgentLocation.Panel, CancellationToken.None));
+			assert.strictEqual(chatModel1.getRequests().length, 0);
+
+			const response = await testService.sendRequest(chatModel1.sessionId, `@${chatAgentWithUsedContextId} test request`);
+			assert(response);
+
+			await response.responseCompletePromise;
+
+			serializedChatData = JSON.parse(JSON.stringify(chatModel1));
+		}
+
+		// try deserializing the state into a new service
+
+		const testService2 = testDisposables.add(instantiationService.createInstance(ChatService));
+
+		const chatModel2 = testService2.loadSessionFromContent(serializedChatData);
+		assert(chatModel2);
+
+		await assertSnapshot(chatModel2.toExport());
+	});
 });