Workload communication

This article describes how the communication between a Microsoft Fabric frontend and backend works. It covers key considerations for admins and users.

Frontend-to-backend communication

Authentication between your frontend and the backend happens over a secure and authenticated channel. To have a token available in your backend for communication with other services, you can use the Fabric frontend to pass the communication to the backend.

Error handling

To propagate any errors that occur in the workload backend to the workload frontend when you work with control plane APIs (CRUD operations and jobs, except for GetItemJobInstanceStateAsync), the workload backend should return an error status code. The response body content should be a serialized JSON file of the class ErrorResponse that is a part of the contracts in the workload backend.

Here's an example:

C#

    var errorResponse = new ErrorResponse
    {
        ErrorCode = ErrorCode,
        Message = ErrorMessage,
        MessageParameters = _messageParameters.Any() ? _messageParameters : null,
        Source = ErrorSource,
        IsPermanent = IsPermanent,
        MoreDetails = Details,
    };
    
    
    return new ContentResult
    {
        StatusCode = (int)HttpStatusCode,
        Content = JsonSerializer.Serialize(errorResponse),
        ContentType = MediaTypeNames.Application.Json,
    };