Given this datamodel:

type PortalCart {
  id: ID! @unique
  owner: PortalUser! @relation(name: "UserCart")
  items: [CartItem!]! @relation(name: "ItemsInCart", onDelete: CASCADE)
  createdAt: DateTime!
  updatedAt: DateTime!
}

type CartItem {
  id: ID! @unique
  cart: PortalCart! @relation(name: "ItemsInCart")
  quantity: Int! @default(value: 1)
  productId: ID!
  createdAt: DateTime!
  updatedAt: DateTime!
}

type PortalUser {
  id: ID! @unique
  createdAt: DateTime!
  updatedAt: DateTime!
  cart: PortalCart @relation(name: "UserCart", onDelete: CASCADE)
  OTTAuthorizations: [OTTAuthorization!]!
  isGuest: Boolean! @default(value: "true")
}

type OTTAuthorization {
  id: ID! @unique
  createdAt: DateTime!
  updatedAt: DateTime!
  videoId: String!
  authorizationCode: String!
  expires: DateTime!
}

I always get this error on prisma generate:

Generating schema... 25ms
Syntax Error: Expected Name, found }

GraphQL request (512:1)
511:
512: }
     ^

There is of course not a line 512 of anything I have been able to view, so I am assuming something about the datamodel is generating an AST that prisma doesnt like.

It's a known issue: https://github.com/prisma/prisma/issues/3452

I feel like all of those types do have scalar fields though, even without the dummy field, am I misunderstanding what a scalar field is?

PortalCart

has no scalar field excluding the system fields (id, createdAt and updatedAt). Try adding

dummy: String

field to that type. No need for required, I think.