Question posted in 
Any recommendation for Authenticating one account to access multiple data from three different servers? I have three servers with (Shopify, WordPress, Laravel) as back-end. All are in different domain/subdomains. Using one account only the user should be able to be authenticated from those three servers in order to get the the data.
Current setup
- WordPress – gmail/fb/ auth (users are currently using this)
I want that user to be authenticated as well in
- Laravel – JWT Auth(another server)
- Shopify(Optional)
2
Answers
In order to make a request to Shopify you need an Access Token or if you are using a Private App – an API Key and Password.
If you are using Access Token you can save it in a shared Database that you can access from what ever language you like as long as you have access to that database.
But I don’t know what you are referring to as “authentication” in this case. If you are creating custom REST API end-points that will request data from Shopify those need to be Authenticated on your side not on the Shopify side.
In addition Shopify in a sense is not a back-end language. You can create a custom App for it, which will be once again hosted on a 3rd party server, but you don’t have access to the Shopify back-end code. So when you are saying Shopify(Optional) it sounds more that you are referring to the Front-end instead of the back-end.
If you plan to make an App in Shopify that other servers will need to request data from the actual authentication has nothing to do with Shopify once again. The authentication is done only if you are inside a Shopify App and you make requests from it, since it passes hmac and other attributes that you need to verify before proceeding with the request.
So to put it simply your question is really difficult to understand in it’s current state.
You cannot do multipass auth with Shopify unless you are on the Plus plan. Anything less and you’re out of luck.