docs(sdk): reference CORS setup

[PetrBulanek]

Summary

This PR clarifies CORS setup requirements for browser-based custom UIs in the Client SDK docs.

• Added CORS guidance in:
  • getting-started.mdx
  • a2a-client.mdx
  • platform-api-client.mdx
• Linked mentions to the existing deployment guide section ../deploy-agent-stack/deployment-guide#cross-origin-resource-sharing-configuration
• Included a brief fallback note that a same-origin frontend proxy can be used if origin allowlisting is not possible.

Linked Issues

Closes: #2062

Documentation

• No Docs Needed:

If this PR adds new feature or changes existing. Make sure documentation is adjusted accordingly. If the docs is not needed, please explain why.

[gemini-code-assist]

Summary of Changes

Hello @PetrBulanek, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request enhances the Client SDK documentation by providing clearer guidance on Cross-Origin Resource Sharing (CORS) setup for custom user interfaces running in a browser. The changes aim to prevent common integration issues by explicitly stating CORS requirements and offering alternative solutions like frontend proxies, thereby improving the developer experience for those building browser-based applications with the Agent Stack SDK.

Highlights

• CORS Guidance Added: New documentation has been added to getting-started.mdx, a2a-client.mdx, and platform-api-client.mdx to clarify CORS setup requirements for browser-based custom UIs.
• Cross-Origin Resource Sharing Configuration Link: Mentions of CORS now include links to the existing deployment guide section on 'Cross-Origin Resource Sharing Configuration' for detailed setup instructions.
• Frontend Proxy Fallback: A brief note has been included suggesting the use of a same-origin frontend proxy as a fallback if direct origin allowlisting for CORS is not feasible.

🧠 New Feature in Public Preview: You can now enable Memory to help Gemini Code Assist learn from your team's feedback. This makes future code reviews more consistent and personalized to your project's style. Click here to enable Memory in your admin console.

Changelog

• docs/development/custom-ui/a2a-client.mdx
  • Added a new bullet point under 'Requirements' to explicitly state the need for CORS to be enabled on the server for frontend origins when running in a browser, including a link to the deployment guide.
• docs/development/custom-ui/getting-started.mdx
  • Inserted a 'Note' block explaining that browser clients require CORS, detailing the need to enable it on the server for the frontend origin, linking to the deployment guide, and suggesting a same-origin frontend proxy as an alternative.
• docs/development/custom-ui/platform-api-client.mdx
  • Added a 'Note' block to inform users that browser clients require CORS, advising to enable server-side CORS for the frontend origin, linking to the deployment guide, and providing a fallback option of using a same-origin frontend proxy.

Activity

• No human activity (comments, reviews) has been recorded on this pull request yet.

Using Gemini Code Assist

The full guide for Gemini Code Assist can be found on our documentation page, here are some quick tips.

Invoking Gemini

You can request assistance from Gemini at any point by creating a comment using either /gemini <command> or @gemini-code-assist <command>. Below is a summary of the supported commands on the current page.

Feature	Command	Description
Code Review	/gemini review	Performs a code review for the current pull request in its current state.
Pull Request Summary	/gemini summary	Provides a summary of the current pull request in its current state.
Comment	@gemini-code-assist	Responds in comments when explicitly tagged, both in pull request comments and review comments.
Help	/gemini help	Displays a list of available commands.

Customization

To customize Gemini Code Assist for GitHub experience, repository maintainers can create a configuration file and/or provide a custom code review style guide (such as PEP-8 for Python) by creating and adding files to a .gemini/ folder in the base of the repository. Detailed instructions can be found here.

Limitations & Feedback

Gemini Code Assist may make mistakes. Please leave feedback on any instances where its feedback is incorrect or counter productive. You can react with 👍 and 👎 on @gemini-code-assist comments. If you're interested in giving your feedback about your experience with Gemini Code Assist for Github and other Google products, sign up here.

You can also get AI-powered code generation, chat, as well as code reviews directly in the IDE at no cost with the Gemini Code Assist IDE Extension.

Footnotes

1. Review the Privacy Notices, Generative AI Prohibited Use Policy, Terms of Service, and learn how to configure Gemini Code Assist in GitHub here. Gemini can make mistakes, so double check it and use code with caution. ↩

[gemini-code-assist]

Code Review

This pull request adds important documentation about CORS setup requirements for browser-based custom UIs. The changes are clear and added to three relevant files: getting-started.mdx, a2a-client.mdx, and platform-api-client.mdx. The new documentation includes links to a more detailed guide and mentions a fallback solution using a proxy. My feedback includes a suggestion to improve consistency in one of the files to ensure important information is not missed by the reader.