Use Supabase with Android Kotlin

Learn how to create a Supabase project, add some sample data to your database, and query the data from an Android Kotlin app.

Set up a Supabase project

Create a new project in the Supabase Dashboard.

After your project is ready, create a table in your Supabase database using the SQL Editor in the Dashboard. Use the following SQL statement to create all tables.

SQL_EDITOR

-- Create the table
CREATE TABLE countries (
  id SERIAL PRIMARY KEY,
  name VARCHAR(255) NOT NULL
);
-- Insert some sample data into the table
INSERT INTO countries (name) VALUES ('United States');
INSERT INTO countries (name) VALUES ('Canada');
INSERT INTO countries (name) VALUES ('Mexico');

Create an Android app with Android Studio

Open Android Studio > New > New Android Project.

Install the Dependencies

Open build.gradle.kts (app) file and add the serialization plug, Ktor client, and Supabase client.

Replace the version placeholders $kotlin_version with the Kotlin version of the project, and $supabase_version and $ktor_version with the respective latest versions.

The latest supabase-kt version can be found here and Ktor version can be found here.

plugins {
  ...
  kotlin("plugin.serialization") version "$kotlin_version"
}
...
dependencies {
  ...
  implementation(platform("io.github.jan-tennert.supabase:bom:$supabase_version"))
  implementation("io.github.jan-tennert.supabase:postgrest-kt")
  implementation("io.ktor:ktor-client-android:$ktor_version")
}

Add internet access permission

Add the following line to the AndroidManifest.xml file under the manifest tag and outside the application tag.

...
<uses-permission android:name="android.permission.INTERNET" />
...

Initialize the Supabase client

You can create a Supabase client whenever you need to perform an API call.

For the sake of simplicity, we will create a client in the MainActivity.kt file at the top just below the imports.

Replace the supabaseUrl and supabaseKey with your own:

Project URL

Anon key

import ...

val supabase = createSupabaseClient(
    supabaseUrl = "https://xyzcompany.supabase.co",
    supabaseKey = "your_public_anon_key"
  ) {
    install(Postgrest)
}
...

Create a data model for countries

Create a serializable data class to represent the data from the database.

Add the following below the createSupabaseClient function in the MainActivity.kt file.

@Serializable
data class Country(
    val id: Int,
    val name: String,
)

Query data from the app

Use LaunchedEffect to fetch data from the database and display it in a LazyColumn.

Replace the default MainActivity class with the following code.

Note that we are making a network request from our UI code. In production, you should probably use a ViewModel to separate the UI and data fetching logic.

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            SupabaseTutorialTheme {
                // A surface container using the 'background' color from the theme
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    CountriesList()
                }
            }
        }
    }
}

@Composable
fun CountriesList() {
    var countries by remember { mutableStateOf<List<Country>>(listOf()) }
    LaunchedEffect(Unit) {
        withContext(Dispatchers.IO) {
            countries = supabase.from("countries")
                              .select().decodeList<Country>()
        }
    }
    LazyColumn {
        items(
            countries,
            key = { country -> country.id },
        ) { country ->
            Text(
                country.name,
                modifier = Modifier.padding(8.dp),
            )
        }
    }
}

Start the app

Run the app on an emulator or a physical device by clicking the Run app button in Android Studio.