Cognito User Pool API - Get user by sub / user ID / UUID

Question

Hi, we want to integrate our service with Cognito user pools, where our data store uses the user ID as the primary key. However, I've learned that Cognito's AdminGetUser method retrieves users by their username. The only way that I'm able to query Cognito to retrieve a user's information by their user ID, is to use ListUsers with a filter for the specific user ID.

Is there really no way to retrieve a user's information by the user ID? If not, then our data store would need to store PII, or we would need to find some other workaround. We're looking to avoid these outcomes.

Trevor Schiavone · Answer

Hello, can you describe what you're looking to achieve in a little more detail?  It sounds like you want to store only the the `sub` attribute for a user, and then be able to query their full details using that identifier. The `sub` attribute is the unique identifier for each user. 
This should be achievable using the `ListUsers` API together with the `sub` as a filter.

You describe this in your question, is there a reason this approach isn't sufficient?

Giovanni Lauria · Answer

AWS Cognito doesn't have a direct method to retrieve user information using the user ID. The workarounds include using the ListUsers method with a filter for the specific user ID, or the GetUser method with an Access Token.

https://docs.aws.amazon.com/cognito/latest/developerguide/how-to-manage-user-accounts.html

Cognito User Pool API - Get user by sub / user ID / UUID

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