This demo uses the Graphcool API Gateway pattern to reuse common functionality in multiple projects. It uses a common Graphcool service that provides weather information, and makes it available through schema stitching in another project that holds address information. This pattern is useful for all kinds of common features (weather, directions, mail sending etc.) that you can now easily reuse across projects.

One service holds information about users and their addresses according to this schema:

type User @model {
  id: ID! @isUnique
  name: String!
  dateOfBirth: DateTime
  address: Address @relation(name: "UserAddress")
}

type Address @model {
  id: ID! @isUnique
  city: String!
  user: User @relation(name: "UserAddress")
}

The other service just contains one resolver function:

type WeatherPayload {
  temperature: Float
}

extend type Query {
  getWeatherByCity(city: String): WeatherPayload
}

This application (the API Gateway) stitches them together, by extending the Address Type with a weather field.

The easiest way to run this example is to use the Apollo Launchpad: https://launchpad.graphql.com/9q0nxlk9r

• Create a .env file in the root of your project folder with the following keys:
  • GRAPHCOOL_ADDRESS_ENDPOINT
  • GRAPHCOOL_WEATHER_ENDPOINT

GRAPHCOOL_ADDRESS_ENDPOINT=https://api.graph.cool/simple/v1/...
GRAPHCOOL_ADDRESS_ENDPOINT=https://api.graph.cool/simple/v1/...

If you don't provide these keys, the application will use demo endpoints (read-only)

• Run yarn install or npm install

• Run yarn start or npm start

• Open http://localhost:3000/playground and execute queries