[BUG] Google Gemini fails with “Invalid URL protocol” when custom base URL is unset

[Nullsire]

Problem (one or two sentences)

When I use google gemini api, it went with error: invalid url. I didn't use custom base url setting.

Context (who is affected and when)

It happens when choose Google Gemini as API provider and do not select custom base url setting.

Reproduction steps

Choose Google Gemini as API provider and do not select custom base url setting, then fill in the api key and send queries.

Expected result

do not report error: Invalid URL protocol: the URL must start with http: or https:. sending request

Actual result

Invalid URL protocol: the URL must start with http: or https:. sending request

Variations tried (optional)

No response

App Version

v3.38.2

API Provider (optional)

Google Gemini

Model Used (optional)

gemini-3-flash-preview

Roo Code Task Links (optional)

No response

Relevant logs or errors (optional)

[roomote]

I'd like to help with this issue, but I need some clarification to ensure I implement the right solution. Could you please provide more details on the following:

1. Full error message: Could you share the complete error message including any stack trace if available? This would help pinpoint exactly where the error originates.

2. Custom Base URL checkbox: In the Gemini settings, did you previously have the "Use custom base URL" checkbox enabled? Even if currently unchecked, there might be a stored value causing the issue.

3. Settings export: If possible, could you export your Roo Code settings (with sensitive info redacted) so I can see the exact configuration state?

4. Version confirmation: You mentioned v3.38.2 - is this the VSCode extension version? Also, is this a fresh install or an upgrade from a previous version?

5. Reproducibility: Does this happen consistently every time, or only intermittently? Does it happen with other Gemini models too (like gemini-2.5-pro or gemini-2.5-flash)?

From my initial analysis, I suspect the issue may be related to:

• A residual/corrupted googleGeminiBaseUrl setting value that's non-empty but invalid (e.g., whitespace or a URL without protocol)
• OR an issue with the @google/genai SDK version (1.29.1) handling internal URL construction

Please mention @roomote in your response with the answers, and I'll be happy to investigate further and implement the fix once I have this information.

[Nullsire]

Here're two snapshots of my setting and error message.
Currently the roo code version is 3.38.3.
This error happens consistently every time and happens to other Gemini models.
I don't know how to export my settings. If you really need them, please give me instructions to export settings.

[Nullsire]

By the way, when I use custom base url, even though models can reply me, an error message constantly pop up. Here's a snapshot of the error. I'm not sure whether it's api provider's problem or the roo code's bug, but I have asked the api provider and they said their api worked fine.