How an application from one subscription can access an API from another subscription

[Raja15]

Hi Experts,

I have 2 azure subscriptions A and B. In Subscription A, I am using Azure ML service and create the Rest API for my AI model, deploy it using AKS, then use APIM which can publish, secure, transform, maintain, and monitor APIs.

If users from subscription B wants to use API (through their applications, scripts etc.) how can they use it?

Q1. Can the applications in subscription B, directly talk to APIM?

Q2. In my architecture, do I need to add any other azure service after APIM, so that applications from subscription B, will be able to use the rest APIs from subscription-A?

My architecture is as below:

[sub A :Synapse analytics-> Azure ML (create Rest API)-> AKS (deploy API) & ACR-> APIM ] <- subB

Please suggest if any other services are missing from this.

Note: I can optionally add a application load balancer after APIM which can help for faster response.

similarly azure monitor can be used for logging or monitoring etc.

[#2]

To access an API from another subscription, you can use Azure Active Directory (Azure AD) to grant access to the application in one subscription to the API in another subscription. You can do this by specifying a web API’s scopes in your client app’s registration, the client app can obtain an access token containing those scopes from the Microsoft identity platform. Within its code, the web API can then provide permission-based access to its resources based on the scopes found in the access token1
Refer the below URL https://learn.microsoft.com/en-us/azure/api-management/api-management-subscriptions

[#3]

@Chandrasekhar_AryaThanks for your reply. Could you please suggest do I need any other service in front of APIM so that subscription can be using API? Or the applications from subscription B can directly interact with APIM?

[#4]

I guess you should be able to access application directly via APIM