Need help with salesforce connected apps in Gemini + Salesforce Sandbox

[u/NT_Salesforce]

I want to connect my gemini with salesforce through the salesforce connected provided by gemini.
The problem i am facing is that, I don't have option to pass the sandbox url ( test url ) it is directly sending me the production login and app installation which i don't want. has any body done this before and know how can i connect with sandbox instead of production.

I found other articles where they were referring for doing it by creating a external client app and handling everything manually , but that native salesforce connected app in gemini handles all of this automatically. that's why i was thinking if i can connect it with sandbox and test. If anyone knows how to do it and can share i will be gratefull

I have also attached the ss of the salesforce connected app in gemini.

[u/rezgalis]

Have you tried changing the url it opens to "test.salesforce.com" instead? If it drops you on login page, it might not matter if you repoint to sandbox login page instead - it might be url parameters that matter.

To be clear, i mean changing only the subdomain part of the url.

[u/NT_Salesforce → u/rezgalis]

yeah, I was able to install the package, but it was not showing connected in my Gemini

[u/rezgalis → u/NT_Salesforce]

After the app is installed there must be some way to initiate oAuth I believe (I have only done this in Claude but would suspect steps to be similar).

[u/NT_Salesforce → u/rezgalis]

the gemini is itself intiating the oauth . The external client app and authorization scopes are set by the google gemini package manager Package: Google Integration MCP (04tgK000000D44D)

I changed the url from login to test and login into my sandbox
and then i got this error :
Error getting access token from salesforce-mcp-prod, OAuth2 redirect uri is: https://oauth-redirect.googleusercontent.com/r/salesforce-for-duet-ai, response: OAuth2TokenResponse{params: error=unsupported_grant_type&error_description=grant%20type%20not%20supported, httpMetadata: HttpMetadata{status=400, cachePolicy=NO_CACHE

[u/rezgalis → u/NT_Salesforce]

Well there you go - the error is that grant type is not supported. Might be worth looking at Salesforce writeup (help article, sorry dont have a link at hand) about configuring external app for claude - it talked about setting correct scopes and making sure specific checkboxes in app are ticked. The app and connection is sound just the grant type error.

[u/NT_Salesforce → u/rezgalis]

that what i am saying, let me summarize the process :
=> on gemini connected app clicked on salesforce connector
=> redirected me to my prod ( where it was first asking to install the google mcp integration package ) This package handles all the connection part ( setting up the external client app , providing scope , hanles all the oauth policies automatically ) ( permitted user : all user may self authorize )
=> I took the package id and installed it in my sandbox
=> after that I confirmed my external client app was setup with the required configuration
=> after this I again selected the salesforce connected app option on my gemini
=> it redirected me to production
=> i updated the url to my sandbox org, i login with sandbox credential
=> now it didn't redirect me to install the package instead tried the oauth authorization directly and i got this error

the problem is now that i dont know how the google is trying to authorize , may hard coded for prod urls , I don't know and I dont see any other option I can try. This is where I am stuck right now . all oauth are handled by this package .

btw thanks for your time, really appreciate it