graphql-kotlin.md

name	description	github
graphql-kotlin	A set of libraries for running GraphQL client and server in Kotlin.	ExpediaGroup/graphql-kotlin

GraphQL Kotlin follows a code first approach for generating your GraphQL schemas. Given the similarities between Kotlin and GraphQL, such as the ability to define nullable/non-nullable types, a schema can be generated from Kotlin code without any separate schema specification. To create a reactive GraphQL web server add following dependency to your Gradle build file:

// build.gradle.kts
implementation("com.expediagroup", "graphql-kotlin-spring-server", latestVersion)

We also need to provide a list of supported packages that can be scanned for exposing your schema objects through reflections. Add following configuration to your application.yml file:

graphql:
  packages:
    - "com.your.package"

With the above configuration we can now create our schema. In order to expose your queries, mutations and/or subscriptions in the GraphQL schema you simply need to implement corresponding marker interface and they will be automatically picked up by graphql-kotlin-spring-server auto-configuration library.

@Component
class HelloWorldQuery : Query {
  fun helloWorld() = "Hello World!!!"
}

This will result in a reactive GraphQL web application with following schema:

type Query {
  helloWorld: String!
}

See graphql-kotlin docs for additial details.