BI engine with REST API to retrieve data

Question

I explain my use case. We are developing a web application to show an analytics dashboard for our customers. The information show has to do with KPIs and metrics extracted through an ETL process from their databases.

Due to an architectural decission we want our web application to access the backend only through web services, so there is a clear separation between front-end and back-end. Thus we need a REST API that returns the desired data when we send a request.

For example, suppose our fact table is about employee salaries and we want to show a graph with the average employee salaries year on year aggregated by employee category. We would send a request like GET to http://api.example.com/salaries?group-by=year&group-by=employee-category&operation=average. It should return the requested data in XML or JSON format, something like the example below.

We have thought about using Qlik or Power BI, but it seems their APIs are Javascript APIs that must be executed on the client side, and the only REST APIs they have are for management.

Do you know a BI software engine that offers this kind of REST API out of the box?

Example response:

[
   {
      "year":2012,
      "salaries":[
         {
            "category":"rookie",
            "salary":30000
         },
         {
            "category":"senior",
            "salary":45000
         }
      ]
   }, 
   {
      "year":2013,
      "salaries":[
         {
            "category":"rookie",
            "salary":35000
         },
         {
            "category":"senior",
            "salary":47000
         }
      ]
   }
]

Answer 1

Logi Analytics provides a rest API for data. It can also render a full fledged visualization that way, but you can get the data and put your own visualization in front of it as well.

Specifically you are looking for their Discovery module and it's DataView concept