Apollo Kotlin
Apollo Kotlin (formerly known as Apollo Android) is a GraphQL client that generates Kotlin and Java models from GraphQL queries.
Apollo Kotlin executes queries and mutations against a GraphQL server and returns results as query-specific Kotlin types. This means you don't have to deal with parsing JSON, or passing around Map
s and making clients cast values to the right type manually. You also don't have to write model types yourself, because these are generated from the GraphQL definitions your UI uses.
Because generated types are query-specific, you can only access data that you actually specify as part of a query. If you don't ask for a particular field in a query, you can't access the corresponding property on the returned data structure.
This library is designed primarily with Android in mind, but you can use it in any Java/Kotlin app, including multiplatform.
Features
- Java and Kotlin Multiplatform code generation
- Queries, Mutations and Subscriptions
- Reflection-free parsing
- Normalized cache
- Custom scalar types
- HTTP cache
- Auto Persisted Queries
- Query batching
- File uploads
- Espresso IdlingResource
- Fake models for tests
- AppSync and graphql-ws websockets
- GraphQL AST parser
Multiplatform
Apollo Kotlin is a Kotlin Multiplatform project.
Here's the current matrix of supported features per platform:
jvm |
Apple¹ | js |
linuxX64 |
|
---|---|---|---|---|
apollo-api (models) |
|
|
|
|
apollo-runtime (network, query batching, apq, ...) |
|
|
|
|
apollo-normalized-cache |
|
|
|
|
apollo-adapters |
|
|
|
|
apollo-normalized-cache-sqlite |
|
|
|
|
apollo-http-cache |
|
|
|
|
¹: Apple currently includes:
macosX64
macosArm64
iosArm64
iosX64
iosSimulatorArm64
watchosArm64
watchosSimulatorArm64
tvosArm64
tvosX64
tvosSimulatorArm64
²: WebSockets are currently not supported on js
Documentation
Check the project website for in depth documentation.
Getting started
If you are new to GraphQL, check out the tutorial that will guide you through building an Android app using Apollo, Kotlin and coroutines.
If you'd like to add Apollo Kotlin to an existing project, follow these steps:
Add the plugin to your build.gradle.kts
:
plugins {
id("com.apollographql.apollo3").version("x.y.z")
}
Add the runtime dependency:
dependencies {
implementation("com.apollographql.apollo3:apollo-runtime:x.y.z")
}
Set the package name to use for the generated models:
apollo {
packageName.set("com.example")
}
Apollo Kotlin supports three types of files:
.graphqls
schema files: describes the types in your backend using the GraphQL syntax..json
schema files: describes the types in your backend using the Json syntax..graphql
executable files: describes your queries and operations in the GraphQL syntax.
By default, Apollo Kotlin requires a schema in your module's src/main/graphql
directory. You can download a schema using introspection with the ./gradlew downloadApolloSchema
task. Sometimes introspection is disabled and you will have to ask your backend team to provide a schema. Copy this schema to your module:
cp ${schema} ${module}/src/main/graphql/
Write a query in a ${module}/src/main/graphql/GetRepository.graphql
file:
query HeroQuery($id: String!) {
hero(id: $id) {
id
name
appearsIn
}
}
Build your project, this will generate a HeroQuery
class that you can use with an instance of ApolloClient
:
// Create a client
val apolloClient = ApolloClient.Builder()
.serverUrl("https://example.com/graphql")
.build()
// Execute your query. This will suspend until the response is received.
val response = apolloClient.query(HeroQuery(id = "1")).execute()
println("Hero.name=${response.data?.hero?.name}")
To learn more about other Apollo Kotlin APIs:
- Execute your first mutation
- Handle custom scalar types
- Factor common patterns using fragments
IntelliJ Plugin
The JS Graphql IntelliJ Plugin provides auto-completion, error highlighting, and go-to-definition functionality for your .graphql
files. You can create a .graphqlconfig
file to use GraphQL scratch files to work with your schema outside product code (such as to write temporary queries to test resolvers).
Releases
Check the changelog for the release history.
Releases are hosted on Maven Central. The plugin is additionally hosted on the Gradle Plugin Portal
plugins {
id("com.apollographql.apollo3").version("x.y.z")
}
repositories {
mavenCentral()
}
dependencies {
implementation("com.apollographql.apollo3:apollo-runtime:x.y.z")
// optional: if you want to use the normalized cache
implementation("com.apollographql.apollo3:apollo-normalized-cache-sqlite:x.y.z")
// optional: if you just want the generated models and parsers and write your own HTTP code/cache code, you can remove apollo-runtime
// and use apollo-api instead
implementation("com.apollographql.apollo3:apollo-api:x.y.z")
}
Snapshots
Latest development changes are available in Sonatype's snapshots repository:
repositories {
maven {
url = uri("https://s01.oss.sonatype.org/content/repositories/snapshots/")
}
}
Requirements
Some platforms have specific requirements:
- Android API level 21+
- JDK 8+
- iOS 13+
For building, it requires:
- Gradle 5.6
- Kotlin 1.4+
Contributing
If you'd like to contribute, please see Contributing.md.
Additional resources
- MortyComposeKMM: A Kotlin Multiplatform Github template using Apollo Kotlin, SwiftUI and Jetpack Compose.
- A journey to Kotlin multiplatform: how the project was moved to Kotlin multiplatform, talk given at Kotliners in June 2020.
- #125, Fragmented Podcast: Why's and How's about Apollo Kotlin and the entire journey.
- GraphQL.org for an introduction and reference to GraphQL itself.
- apollographql.com to learn about Apollo open-source and commercial tools.
- The Apollo blog for long-form articles about GraphQL, feature announcements for Apollo, and guest articles from the community.
- The Apollo Twitter account for in-the-moment news.
Who is Apollo?
Apollo builds open-source software and a graph platform to unify GraphQL across your apps and services. We help you ship faster with:
- Apollo Studio – A free, end-to-end platform for managing your GraphQL lifecycle. Track your GraphQL schemas in a hosted registry to create a source of truth for everything in your graph. Studio provides an IDE (Apollo Explorer) so you can explore data, collaborate on queries, observe usage, and safely make schema changes.
- Apollo Federation – The industry-standard open architecture for building a distributed graph. Use Apollo’s gateway to compose a unified graph from multiple subgraphs, determine a query plan, and route requests across your services.
- Apollo Client – The most popular GraphQL client for the web. Apollo also builds and maintains Apollo iOS and Apollo Kotlin.
- Apollo Server – A production-ready JavaScript GraphQL server that connects to any microservice, API, or database. Compatible with all popular JavaScript frameworks and deployable in serverless environments.
Learn how to build with Apollo
Check out the Odyssey learning platform, the perfect place to start your GraphQL journey with videos and interactive code challenges. Join the Apollo Community to interact with and get technical help from the GraphQL community.