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.

Create a Supabase project

Go to database.new and create a new Supabase project.

Alternatively, you can create a project using the Management API:

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# First, get your access token from https://supabase.com/dashboard/account/tokens
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export SUPABASE_ACCESS_TOKEN="your-access-token"
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# List your organizations to get the organization ID
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curl -H "Authorization: Bearer $SUPABASE_ACCESS_TOKEN" \
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  https://api.supabase.com/v1/organizations
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# Create a new project (replace <org-id> with your organization ID)
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curl -X POST https://api.supabase.com/v1/projects \
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  -H "Authorization: Bearer $SUPABASE_ACCESS_TOKEN" \
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  -H "Content-Type: application/json" \
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  -d '{
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    "organization_id": "<org-id>",
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    "name": "My Project",
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    "region": "us-east-1",
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    "db_pass": "<your-secure-password>"
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  }'

When your project is up and running, go to the Table Editor, create a new table and insert some data.

Alternatively, you can run the following snippet in your project's SQL Editor. This will create a instruments table with some sample data.

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-- Create the table
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create table instruments (
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  id bigint primary key generated always as identity,
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  name text not null
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);
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-- Insert some sample data into the table
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insert into instruments (name)
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values
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  ('violin'),
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  ('viola'),
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  ('cello');
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alter table instruments enable row level security;

Make the data in your table publicly readable by adding an RLS policy:

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create policy "public can read instruments"
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on public.instruments
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for select to anon
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using (true);

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.

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

Add internet access permission

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

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

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

Publishable key

Anon key

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

You can also get the Project URL and key from the project's Connect dialog.

Changes to API keys

Supabase is changing the way keys work to improve project security and developer experience. You can read the full announcement, but in the transition period, you can use both the current anon and service_role keys and the new publishable key with the form sb_publishable_xxx which will replace the older keys.

In most cases, you can get the correct key from the Project's Connect dialog, but if you want a specific key, you can find all keys in the API Keys section of a Project's Settings page:

For legacy keys, copy the anon key for client-side operations and the service_role key for server-side operations from the Legacy API Keys tab.
For new keys, open the API Keys tab, if you don't have a publishable key already, click Create new API Keys, and copy the value from the Publishable key section.

Read the API keys docs for a full explanation of all key types and their uses.

Create a data model for instruments

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

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

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

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.

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class MainActivity : ComponentActivity() {
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    override fun onCreate(savedInstanceState: Bundle?) {
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        super.onCreate(savedInstanceState)
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        setContent {
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            SupabaseTutorialTheme {
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                // A surface container using the 'background' color from the theme
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                Surface(
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                    modifier = Modifier.fillMaxSize(),
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                    color = MaterialTheme.colorScheme.background
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                ) {
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                    InstrumentsList()
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                }
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            }
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        }
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    }
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}
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@Composable
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fun InstrumentsList() {
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    var instruments by remember { mutableStateOf<List<Instrument>>(listOf()) }
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    LaunchedEffect(Unit) {
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        withContext(Dispatchers.IO) {
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            instruments = supabase.from("instruments")
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                              .select().decodeList<Instrument>()
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        }
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    }
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    LazyColumn {
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        items(
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            instruments,
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            key = { instrument -> instrument.id },
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        ) { instrument ->
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            Text(
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                instrument.name,
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                modifier = Modifier.padding(8.dp),
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            )
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        }
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    }
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}

Start the app

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