Artifact inlineData base64 is weird.

[cjgammon]

Describe the bug
The base64 data returned by the API is in a format that requires processing to use in any web application. It seems to be in base64URL format which requires replacing non standard characters.

To Reproduce
Call the /artifacts/${artifactName} endpoint
Try to turn it into a usable image.

Expected behavior
I don't need to manually change the data to utilize it.

Screenshots
If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: OSX 15.3.2
• Python version(python -V): 3.11.5
• ADK version(pip show google-adk): 0.1.0

Additional context

Current processing required is

base64url.replace(/-/g, '+').replace(/_/g, '/');

[cjgammon]

At the very least this should be documented somewhere more clearly.

[DeanChensj]

Hi @cjgammon , thanks for reporting this issue.

The artifact service return google.genai.types.Part see our doc https://screenshot.googleplex.com/3MpKX2QLodQyoMt.

It's a common issue that extra processing is needed, this is how we handle it in our adk-web code:
https://github.com/google/adk-web/blob/main/src/app/components/chat/chat.component.ts#L50

Reassign this to @polong-lin to see if we want to add more documentation around this processing.