Inserting GraphQL record from JSON payload

Question

I’m working on building an SMS platform, so part of this is for the SMS gateway to forward the SMS to a public URL with a JSON Payload (which I have no control of the format) so I need to have it accepted by a lambda in Slash GraphQL and then from there insert it as a record in the Graph database for later processing.

The SMS gateway will send an HTTP POST with JSON payload to the lambda function.

I have deployed this type:

type InboundSMS  {
  id: String! @id
  dateTime: String!
  destinationAddress: String!
  messageId: String!
  message: String!
  resourceURL: String!
  senderAddress: String!
}

As the schema for the incoming SMS with JSON format:

HTTP POST

{
  "inboundSMSMessageList":{
      "inboundSMSMessage":[
         {
            "dateTime":"Fri Nov 22 2013 12:12:13 GMT+0000 (UTC)",
            "destinationAddress":"tel:21581234",
            "messageId":null,
            "message":"Hello",
            "resourceURL":null,
            "senderAddress":"tel:+639171234567"
         }
       ],
       "numberOfMessagesInThisBatch":1,
       "resourceURL":null,
       "totalNumberOfPendingMessages":null
   }
}