Updating GenUI to current version of 0.9 by sfshaza2 · Pull Request #13161 · flutter/website

sfshaza2 · 2026-03-09T22:45:31Z

The GenUI package has been updating to 0.9 (from 0.7) and includes breaking changes. This PR updates those docs/examples.

gemini-code-assist

Code Review

This pull request does a great job of updating the documentation to reflect the breaking changes in GenUI version 0.9. The renaming of components and updates to the API are consistently applied across the documents. However, several code examples in the 'get-started.md' file are incomplete, commented out, or contain confusing variable names. For a guide aimed at new users, it's crucial that these examples are clear and fully functional. I've provided specific suggestions to address these issues and improve the clarity and completeness of the documentation.

_{Note: Security Review has been skipped due to the limited scope of the PR.}

gemini-code-assist · 2026-03-09T22:47:13Z

src/content/ai/genui/get-started.md

+        _connector.stream.listen((A2uiMessage message) {
+          // Pass messages to Adapter/Controller
        });


The code example is incomplete. The comment // Pass messages to Adapter/Controller is not helpful for a user trying to follow the guide. Since the _connector.stream emits A2uiMessage objects and _surfaceController.handleMessage accepts them, the implementation should directly connect them.

Suggested change

_connector.stream.listen((A2uiMessage message) {

// Pass messages to Adapter/Controller

});

_connector.stream.listen(_surfaceController.handleMessage);

Yes, this is fine as an example.

gemini-code-assist · 2026-03-09T22:47:13Z

src/content/ai/genui/get-started.md

      void dispose() {
        _textController.dispose();
        _uiAgent.dispose();
-        _a2uiMessageProcessor.dispose();
-        _contentGenerator.dispose();
+        _surfaceController.dispose();
        super.dispose();
      }


The _connector likely holds resources like a WebSocket connection that need to be released. It should be disposed of in the dispose method, similar to how _contentGenerator was handled in the previous version. Please add _connector.dispose(); (or a similar method like close()) to prevent resource leaks.

Suggested change

void dispose() {

_textController.dispose();

_uiAgent.dispose();

_a2uiMessageProcessor.dispose();

_contentGenerator.dispose();

_surfaceController.dispose();

super.dispose();

}

void dispose() {

_textController.dispose();

_uiAgent.dispose();

_surfaceController.dispose();

_connector.dispose();

super.dispose();

}

Yes, it should dispose.

gemini-code-assist · 2026-03-09T22:47:13Z

src/content/ai/genui/get-started.md

-        _genUiConversation = GenUiConversation(
-          a2uiMessageProcessor: _a2uiMessageProcessor,
-          contentGenerator: contentGenerator,
+        // ... initialize your LLM Client of choice using promptBuilder.systemPrompt


This comment makes the example incomplete and hard to follow. It would be much more helpful to show a concrete (even if simplified) example of how to initialize an LLM client and connect it to the rest of the GenUI components. For instance, you could continue the google_generative_ai example from earlier.

No, this is vague on purpose.

gemini-code-assist · 2026-03-09T22:47:13Z

src/content/ai/genui/get-started.md

+       void _sendMessage(String text) {
+         if (text.trim().isEmpty) return;
+         // _conversation.sendMessage(text);
+         // Or pass chunk texts directly via LLM SDK stream into the transportAdapter
+       }


The example for sending a message is entirely commented out, which is not helpful for a user. Please provide a working, uncommented example of how to send a message using either _conversation.sendMessage(text) or by streaming to the transport adapter.

Suggested change

void _sendMessage(String text) {

if (text.trim().isEmpty) return;

// _conversation.sendMessage(text);

// Or pass chunk texts directly via LLM SDK stream into the transportAdapter

}

void _sendMessage(String text) {

if (text.trim().isEmpty) return;

_conversation.sendMessage(text);

}

I think just comment in this line:

// _conversation.sendMessage(text);

gemini-code-assist · 2026-03-09T22:47:13Z

src/content/ai/genui/get-started.md

+    final messageProcessor = SurfaceController(catalogs: catalogs);
+    final transportAdapter = A2uiTransportAdapter();
+    transportAdapter.messageStream.listen(messageProcessor.handleMessage);
+
+    final promptBuilder = PromptBuilder.chat(
      catalog: catalog,
-      systemInstruction: 'You are a helpful assistant.',
-      modelName: 'models/gemini-2.5-flash',
+      instructions: 'You are a helpful assistant.',
+    );
+
+    final model = GenerativeModel(
+      model: 'gemini-2.5-flash',
      apiKey: 'YOUR_API_KEY', // Or set GEMINI_API_KEY environment variable.
+      systemInstruction: Content.system(promptBuilder.systemPrompt),
    );

-    final conversation = GenUiConversation(
-      contentGenerator: contentGenerator,
-      a2uiMessageProcessor: messageProcessor,
+    final conversation = Conversation(
+      surfaceController: messageProcessor,
+      transportAdapter: transportAdapter,
    );


For better clarity and consistency with the new API, it would be best to rename the messageProcessor variable to surfaceController. The class is now SurfaceController, and using the same name for the variable makes the example easier to understand, especially for new users.

Suggested change

final messageProcessor = SurfaceController(catalogs: catalogs);

final transportAdapter = A2uiTransportAdapter();

transportAdapter.messageStream.listen(messageProcessor.handleMessage);

final promptBuilder = PromptBuilder.chat(

catalog: catalog,

systemInstruction: 'You are a helpful assistant.',

modelName: 'models/gemini-2.5-flash',

instructions: 'You are a helpful assistant.',

);

final model = GenerativeModel(

model: 'gemini-2.5-flash',

apiKey: 'YOUR_API_KEY', // Or set GEMINI_API_KEY environment variable.

systemInstruction: Content.system(promptBuilder.systemPrompt),

);

final conversation = GenUiConversation(

contentGenerator: contentGenerator,

a2uiMessageProcessor: messageProcessor,

final conversation = Conversation(

surfaceController: messageProcessor,

transportAdapter: transportAdapter,

);

final surfaceController = SurfaceController(catalogs: catalogs);

final transportAdapter = A2uiTransportAdapter();

transportAdapter.messageStream.listen(surfaceController.handleMessage);

final promptBuilder = PromptBuilder.chat(

catalog: catalog,

instructions: 'You are a helpful assistant.',

);

final model = GenerativeModel(

model: 'gemini-2.5-flash',

apiKey: 'YOUR_API_KEY', // Or set GEMINI_API_KEY environment variable.

systemInstruction: Content.system(promptBuilder.systemPrompt),

);

final conversation = Conversation(

surfaceController: surfaceController,

transportAdapter: transportAdapter,

);

Yes, do this.

gemini-code-assist · 2026-03-09T22:47:13Z

src/content/ai/genui/get-started.md

+        final responseText = await _connector.connectAndSend(
+            message,
+            clientCapabilities: A2uiClientCapabilities(supportedProtocols: ['a2ui/0.9.0'])
+        );
+
+        // Handling response depends on your app's logic


The responseText variable is unused, and the comment // Handling response depends on your app's logic is vague for an example. The response from the agent should be handled, for instance, by displaying it to the user. This would make the example more complete and useful.

Suggested change

final responseText = await _connector.connectAndSend(

message,

clientCapabilities: A2uiClientCapabilities(supportedProtocols: ['a2ui/0.9.0'])

);

// Handling response depends on your app's logic

final responseText = await _connector.connectAndSend(

message,

clientCapabilities: A2uiClientCapabilities(supportedProtocols: ['a2ui/0.9.0'])

);

if (responseText.isNotEmpty) {

setState(() {

_messages.insert(0, ChatMessage.model([TextPart(responseText)]));

});

}

I think we can ignore this for now.

gemini-code-assist · 2026-03-09T22:47:13Z

src/content/ai/genui/get-started.md

-      additionalTools: _a2uiMessageProcessor.getTools(),
    );
+
+    // Pass promptBuilder.systemPrompt to your LLM Config


This comment leaves the example incomplete. Please provide a concrete code snippet showing how to use promptBuilder.systemPrompt with an LLM configuration, similar to the GenerativeModel example earlier in the document. This would make the guide much easier to follow.

This is vague on purpose.

gspencergoog

Looks great!

flutter-website-bot · 2026-03-09T22:51:25Z

Visit the preview URL for this PR (updated for commit e92123a):

https://flutter-docs-prod--pr13161-update-genui-docs-vtyga3he.web.app

abdallahshaban557 · 2026-03-09T22:52:57Z

src/content/ai/genui/get-started.md

 [Enable the Gemini API]: https://firebase.google.com/docs/gemini-in-firebase/set-up-gemini
 [Firebase's Flutter setup guide]: https://firebase.google.com/docs/flutter/setup
-[`genui_firebase_ai`]: {{site.pub-pkg}}/genui_firebase_ai
+[`firebase_vertexai`]: {{site.pub-pkg}}/firebase_vertexai


this package is discontinued

abdallahshaban557 · 2026-03-09T22:55:14Z

src/content/ai/genui/get-started.md

    to add Firebase to your app.

- 4. Use `dart pub add` to add `genui` and [`genui_firebase_ai`][] as
+ 4. Use `dart pub add` to add `genui` and [`firebase_vertexai`][] as


this isn't the right package - I believe it should be firebase_ai_logic @sfshaza2

Updating GenUI to current version of 0.9

e92123a

sfshaza2 requested review from abdallahshaban557 and gspencergoog March 9, 2026 22:45

sfshaza2 requested a review from a team as a code owner March 9, 2026 22:45

gemini-code-assist bot reviewed Mar 9, 2026

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gspencergoog approved these changes Mar 9, 2026

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abdallahshaban557 reviewed Mar 9, 2026

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