JSON Composition for sending:

{
    "auth" : authorization token
    ,"do" :
      [
        {
            *"action" : integer (0/inactive, 1/insert, 2/change)
            *,"sku" : product sku (no special characters)
            ,"gtin" : product EAN
            *,"description" : product description
            *,"type" : 0/simple, 1/kit, 2/virtual (no WMS control) 
            ,"measure" : unit of measure (UN, PC...)
            ,"weight" : weight in grams (no decimal, default = 0)
            ,"height" : height in millimeters (no decimal, default = 0)
            ,"width" : width in millimeters (no decimal, default = 0)
            ,"depth" : depth in millimeters (no decimal, default = 0)
            ,"batch" : batch control (1/yes, 0/no)
            ,"composition" :
              [
                {
                  "sku" : sku of the product that composes this one
                  ,"amount" : quantity of products composing the KIT
                }
              ]
        }
      ]
  }
Note: 
a. KITs cannot be changed; they must be deleted and re-inserted.
b. An SKU used in a KIT must not be used in a product and vice-versa.

Returns with:
{
    "code": 200,
    "result": [
        {
            "code": integer,
            "message": error description
        }
    ]
}

code
200: request fulfilled
402: invalid request
406: missing tags
410: "action" must be informed
411: "sku" must be informed
412: "description" must be informed
413: "type" must be informed
414: kit composition should not be informed
415: kit composition must be informed
416: non-existent SKU
417: SKU already exists
418: Product description contains characters that could not be processed
419: kit already exists
423: SKU used to compose the kit does not exist
425: kit cannot be changed
500: invalid auth
501: invalid credential
502: client blocked
503: request excess (11 per minute)