1. Course intro and setup
10m

Overview

Welcome! In this first course in Odyssey's Kotlin series, we'll enable an app to communicate with a by adding the library. We'll start by downloading a schema, running codegen, and writing queries and . By the end of the series, you'll be equipped to handle errors, pagination, authentication, and !

In this lesson, we will:

  • Learn about what we're building, and the technologies that help us build it
  • Set up our project environment

What is GraphQL?

Let's begin with the most important question of the course. What is GraphQL?

is the developer-friendly query language for the modern web. It transforms how apps fetch data from an API, enabling you to get exactly what you need with a single query—instead of wrangling responses from a patchwork of REST endpoints.

With a strongly typed schema at its core, helps you define relationships between data across any number of systems, empowering you to focus on what your data can do instead of where it's stored.

Throughout this course, we'll learn how to integrate with our Android app, making it easier to serve up data to our users and build faster than ever before. Get ready to roll up your sleeves, write some code, test your understanding, and build something cool!

A diagram showing GraphQL as the contact point between multiple clients and the complex architecture of a modern backend

What we're building

We're going to build an app that lets us "book a seat" on any of the rockets that have been sent into space by SpaceX. We'll connect to a that's hosted on Heroku and is powered by Apollo Server.

If you're curious about how to build your own , check out Odyssey's backend courses, available in a variety of programming languages.

Prerequisites

To follow along...

Clone the repository

In the directory of your choice with your preferred terminal, clone the app's starter repository:

git clone https://github.com/apollographql/apollo-kotlin-odyssey

We'll work out of the start directory.

Note: If you get stuck at any time during the course, feel free to check out the final directory for some help: it contains the completed app.

Task!

Project setup

Navigate to the apollo-kotlin-odyssey directory, and open up the start folder in Android Studio.

Folder structure for opening project

Android Studio will take some time to index the contents of the project. Take some time to look around. You should see three files:

  • LaunchList.kt is the first screen. You will display a list of there.
  • LaunchDetails.kt will display details about a and give you the opportunity to book a seat.
  • Login.kt will allow you to log in before booking the seat.

Now build and run the project.

You should see a list with static placeholder data:

Starting app state

Install the Apollo GraphQL plugin for Android Studio

We recommend installing the Android Studio Plugin, which has a ton of helpful features including autocomplete for files, automatic code generation, and more.

Go to Android Studio -> Settings... -> Plugins. In the "Marketplace" tab, search for "Apollo " and install the plugin.

Apollo GraphQL Marketplace Page

Now, let's add to the project.

Visit Apollo Kotlin on GitHub

You can view the Changelog for every version of on our GitHub releases page. It is also displayed at the top of the apollo-kotlin repo.

This course uses 4.1.0 because it is the latest version at the time of writing. Feel free to use a more recent version if one is available.

Apply the Apollo Gradle plugin

Add the Apollo plugin to the version catalog in gradle/libs.versions.toml. The Apollo plugin ID is com.apollographql.apollo:

gradle/libs.versions.toml
[versions]
# ...
apollo = "4.1.0"


[plugins]
# ...
apollo = { id = "com.apollographql.apollo", version.ref = "apollo" }

Then apply the Apollo plugin in app/build.gradle.kts. There are two build.gradle.kts in the project - make sure to use the one in the app directory.

Note: for simplicity, we are loading the plugin and applying it at the same time. In a real app, you may want to load the plugin in the root project to avoid classpath issues.

app/build.gradle.kts
plugins {
    alias(libs.plugins.android.application)
    // ...
    alias(libs.plugins.apollo)
}

The plugin contains the compiler that generates models from your queries when you build your project.

Configure the Apollo Gradle plugin

Configure the Apollo Gradle plugin to specify the package in which the Kotlin files will be generated. Put this at the end of app/build.gradle.kts:

app/build.gradle.kts
apollo {
  service("service") {
    packageName.set("com.example.rocketreserver")
  }
}

Add dependencies

Now add apollo-runtime to the list of dependencies. This is the part of the SDK that executes queries and parses responses.

First add the dependency to the version catalog:

gradle/libs.versions.toml
[libraries]
# ...
apollo-runtime = { module = "com.apollographql.apollo:apollo-runtime" }

Then add the dependency to the app/build.gradle.kts file:

app/build.gradle.kts
dependencies {
    // ...
  implementation(libs.apollo.runtime)
}

Android Studio will display a yellow banner, A project sync may be necessary for the IDE to work properly. Click Sync Now.

Todo list

Up next

Your project should now be ready to use the SDK. Next, we'll explore the API we'll connect to our project.

Next

Share your questions and comments about this lesson

This course is currently in

beta
. Your feedback helps us improve! If you're stuck or confused, let us know and we'll help you out. All comments are public and must follow the Apollo Code of Conduct. Note that comments that have been resolved or addressed may be removed.

You'll need a GitHub account to post below. Don't have one? Post in our Odyssey forum instead.