graphene/docs/pages/guide/interface.md

Interfaces

An Interface contains the essential fields that will be shared among multiple ObjectTypes.

The basics:

• Each Interface is a Python class that inherits from graphene.Interface.
• Each attribute of the Interface represents a GraphQL field.

Quick example

This example model defines a Character, which has a name. Human and Droid inherit from it.

import graphene

# Character is an Interface
class Character(graphene.Interface):
	name = graphene.String()

# Human is an ObjectType, as inherits an interface
class Human(Character):
	born_in = graphene.String()

# Droid is an ObjectType, as inherits an interface
class Droid(Character):
	function = graphene.String()

name is a field in the Character interface that will be in both Human and Droid ObjectTypes (as those inherit from Character). Each ObjectType also define extra fields at the same time.

The above types would have the following representation in a schema:

interface Character {
  name: String
}

type Droid implements Character {
  name: String
  function: String
}

type Human implements Character {
  name: String
  bornIn: String
}