Prisma

how would i calculate a variable during a mutation?   is this even possible:

mutation CreateNewQuote(
  $customerId: ID,
  $preparedByEmployeeId: ID, 
  $preparedForCustomerContactId: ID,
) {
  createQuote(
    customerId: $customerId,
    quoteNumber: “NEED TO CALCULATE WITH A MUTATION CALLBACK”,
    employeeId: $preparedByEmployeeId,
    customerContactId: $preparedForCustomerContactId
  ) {
    id,
    quoteNumber
  }
}

i suppose i could create with quoteNumber: “TBD” or something, then mutation callback lambda could calculate, then front-end subscribes to updates on this quote and picks up the calculated value later.   

nested mutation of some sort?