Field arguments

Any field can accept a named, unordered list of arguments. Arguments can be scalars, enums, or input objects. An argument can be non-null to indicate it is required. Optional arguments can have a default value, like width below.

type User {
  # no arguments
  name

  # an optional scalar argument with a default value
  profilePic(width: Int = 100): Url
}

type Mutation {
  # a non-null enum argument
  pokemonGo(direction: Direction!): Boolean

  # three non-null scalar arguments
  createPost(authorId: ID!, title: String!, body: String!): Post
}

Input objects

Input objects are objects that are only used as arguments. An input object is often the sole argument to mutations (see Chapter 11: Schema design > Mutations > Arguments).

An input object is a list of input fields—scalars, enums, and other input objects.

type Mutation {
  createPost(input: CreatePostInput!): Post
}

input CreatePostInput {
  authorId: ID!
  title: String = "Untitled"
  body: String!
}

Note that:

• Input object fields can have default values.
• The declaration keyword is input, not the type keyword that is used for output objects.