Created a new agent to showcase the list of components in the std catalog. Also fixed a few component bugs by dmandar · Pull Request #596 · google/A2UI

dmandar · 2026-02-04T06:24:03Z

Description

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Pre-launch Checklist

I signed the CLA.
I read the Contributors Guide.
I read the Style Guide.
I have added updates to the CHANGELOG.
I updated/added relevant documentation.
My code changes (if any) have tests.

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…ging on-the-wire a2UI JSON and actions

dmandar · 2026-02-04T06:25:12Z

gemini-code-assist

Code Review

This pull request introduces a new component gallery sample, which is a valuable addition for demonstrating A2UI capabilities. The changes include a new agent, a Lit-based client, and improvements to existing UI components, notably a much-improved MultipleChoice component. While this is a great feature, there are several areas for improvement. The new code appears to have been partially copied from another sample, resulting in confusing naming and some irrelevant files that should be cleaned up. The new agent code also has some Python style guide violations. Finally, this large addition of functionality lacks corresponding tests for the agent logic, which is something to address per the repository's contribution guidelines.

renderers/lit/src/0.8/ui/multiple-choice.ts

samples/agent/adk/component_gallery/__main__.py

samples/agent/adk/component_gallery/agent.py

samples/agent/adk/component_gallery/agent_executor.py

samples/client/lit/component_gallery/README.md

samples/client/lit/component_gallery/middleware/a2a.ts

dmandar · 2026-02-04T06:59:24Z

Will be overhauling docs for this and other changes in a followup PR

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

… into md-componentslistagent

jacobsimionato

I'm wondering if we can tweak the structure of this to try to aim for consistency and reduce the overall side of the code we are maintaining.

There are already a couple of examples of galleries:

Catalog gallery at samples/client/angular/projects/gallery, see https://github.com/google/A2UI/blob/main/samples/client/angular/projects/gallery/src/app/features/library/library.component.ts
AG-UI's composer has a gallery: #365, https://a2ui-composer.ag-ui.com/components

I do think it'd be nice to have a gallery for each renderer, so we can compare how they render. I believe the other two galleries use the React and Angular renderers, so there is value in creating a Lit sample. How about trying to follow the structure of the other apps, to aim for consistency? This might involve:

Building this as a client-only app rather than an agent + client. I'm not sure if the agent adds much value if it just outputs canned content.
Reusing the same sample content as the other gallery apps. I think AG-UI folk provided nice sample content. Maybe we can reuse that in the other galleries? Then it's easy to compare between them.

dmandar · 2026-02-05T18:11:29Z

I'm wondering if we can tweak the structure of this to try to aim for consistency and reduce the overall side of the code we are maintaining.

There are already a couple of examples of galleries:

Catalog gallery at samples/client/angular/projects/gallery, see https://github.com/google/A2UI/blob/main/samples/client/angular/projects/gallery/src/app/features/library/library.component.ts

AG-UI's composer has a gallery: Add A2UI composer #365, https://a2ui-composer.ag-ui.com/components

I do think it'd be nice to have a gallery for each renderer, so we can compare how they render. I believe the other two galleries use the React and Angular renderers, so there is value in creating a Lit sample. How about trying to follow the structure of the other apps, to aim for consistency? This might involve:

Building this as a client-only app rather than an agent + client. I'm not sure if the agent adds much value if it just outputs canned content.

Reusing the same sample content as the other gallery apps. I think AG-UI folk provided nice sample content. Maybe we can reuse that in the other galleries? Then it's easy to compare between them.

I think there is value in having the agent as it is an e2e loop that gets tests - this is how most customers would use it too. In the sample, clicking on the log value button, the action is sent up to the agent and the agent updates a second surface.
I agree it will be nice to have the same overall layout for all renderers, i can do that as a followup. This is to unblock an internal team who wants to see this list. Also, this sample has an event logger built in which adds transparency to how things work internally

gspencergoog

This is a rubber stamp, as I'm not qualified for the web code.

dmandar · 2026-02-06T18:35:04Z

I will check this in given the urgency and there are minimal renderer changes (bug fixes only). Will do any changes in followup as reqd

Chatted offline. We will have any followup request from dit addressed later.

ditman

Some small comments in general. The changes to the web renderer seem all right. The new example app is rather large, but if you like it, let's go with it.

Note that there's a bunch of missing copyright notices at the top of the python code that should be there.

ditman · 2026-02-06T18:24:27Z

renderers/lit/src/0.8/ui/multiple-choice.ts

+      return Array.isArray(this.selections) ? this.selections : [];
+    }
+    if (Array.isArray(this.selections)) {


Why is the Array.isArray(this.selections) check duplicated?

ditman · 2026-02-06T18:26:58Z

renderers/lit/src/0.8/ui/checkbox.ts

+
+

Why the extra whitespace?

(PS: We probably need autoformatting rules in the repo)

ditman · 2026-02-06T18:27:44Z

samples/agent/adk/component_gallery/__main__.py

Does this file needa copyright header, like the a2ui schema?

ditman · 2026-02-06T18:28:01Z

samples/agent/adk/component_gallery/agent.py

(Same comment about the copyright header)

ditman · 2026-02-06T18:28:24Z

samples/agent/adk/component_gallery/agent_executor.py

(Missing copyright header)

ditman · 2026-02-06T18:29:18Z

samples/agent/adk/component_gallery/tools.py

Copyright header missing.

Also it might be nice to have an example of a silly tool for demonstration purposes (or remove the wiring for the empty file for clarity of the sample?)

ditman · 2026-02-06T18:48:57Z

samples/client/lit/component_gallery/README.md

+
+## Running
+
+This sample depends on the Lit renderer. Before running this sample, you need to build the renderer.


Can you also add a script(s) to run the sample in the samples/lit/package.json?

dmandar added 3 commits February 2, 2026 22:26

fix contact sample

8f347c6

Fix dropdown and make it multi-choice

c6e03b3

Add a new component_gallery sample agent and client that allows debug…

ee36b32

…ging on-the-wire a2UI JSON and actions

dmandar requested review from gspencergoog and jacobsimionato February 4, 2026 06:24

github-project-automation bot added this to A2UI Feb 4, 2026

github-project-automation bot moved this to Todo in A2UI Feb 4, 2026

dmandar changed the title ~~Created a new agent to showcase the list of components in the std catalog.~~ Created a new agent to showcase the list of components in the std catalog. Aso fixed a few component bugs Feb 4, 2026

dmandar changed the title ~~Created a new agent to showcase the list of components in the std catalog. Aso fixed a few component bugs~~ Created a new agent to showcase the list of components in the std catalog. Also fixed a few component bugs Feb 4, 2026

gemini-code-assist bot reviewed Feb 4, 2026

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Merge branch 'main' into md-componentslistagent

276582a

dmandar and others added 3 commits February 3, 2026 22:59

Update samples/client/lit/component_gallery/README.md

667e9ba

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

fix modal

828d6d9

Merge branch 'md-componentslistagent' of https://github.com/google/A2UI…

eae7f16

… into md-componentslistagent

jacobsimionato previously requested changes Feb 5, 2026

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Address review comments

af7e4d1

dmandar requested a review from jacobsimionato February 6, 2026 00:27

gspencergoog approved these changes Feb 6, 2026

View reviewed changes

jacobsimionato requested a review from ditman February 6, 2026 04:53

dmandar merged commit 401409e into main Feb 6, 2026
10 checks passed

dmandar deleted the md-componentslistagent branch February 6, 2026 18:37

github-project-automation bot moved this from Todo to Done in A2UI Feb 6, 2026

ditman reviewed Feb 6, 2026

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ditman mentioned this pull request Feb 6, 2026

Add regex support for textfield on lit renderer #605

Merged


		## Running

		This sample depends on the Lit renderer. Before running this sample, you need to build the renderer.

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dmandar commented Feb 4, 2026

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dmandar commented Feb 5, 2026 •

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