External B2C Tenant application accessing Power BI embedded via API hosted in another tenant

Hi, brian_641 

Regarding the issue you raised, my solution is as follows:

1.You might consider creating a multi-tenant application and using its service principal as an external member to authenticate against the main tenant’s API.

One limitation to be aware of is that you cannot grant access to more than 1,000 workspaces to an embedded identity.

Below is a screenshot from the relevant documentation:

Additionally, in a multi-tenant solution, each customer has their own tenant and workspace, and the application will embed Power BI content into these tenants.

Below is a screenshot from the relevant documentation:

For detailed information, please refer to:

Develop scalable multitenancy applications with Power BI embedding - Power BI | Microsoft Learn 

2.You can also try modifying cross-tenant access Settings:

Cross-tenant access settings - Notes from the field - Microsoft Community Hub

I hope my response has been helpful to you.

Of course, if you have any new ideas, you are welcome to contact us.
 

Best Regards,

Leroy Lu

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