So my setup is very unorthodox. I'm creating a service that uses dynomo for storing authentication tokens for a user. My actual auth is happening through a lambda that calls a shopify API. I then use a custom lambda auth handler to accept or decline specific API requests base on if the user has a valid session or not. Additionally I use an apiKey auth method for unauthenticated routes like login, and now I'm using custom mutations using lambda functions that should have more permissions than I want to give a customer. So I'm wondering how I can setup an IAM auth for that, so I can give read and write permissions to my custom lambdas that need to make mutations but my users can only read using the custom lambda auth.
And is it even possible to have all 3 auth mods at the same time? And if not what's a potential workaround. I have no intention of using Cognito because we already manage our users with Shopify, so that would be duplicative.