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.

1. Create a Supabase project#

Before you can use Supabase, you need a Supabase project. You can create a project visually in the Dashboard or programmatically using the Management API.

Create a new Supabase project from the Dashboard of any organization you belong to.

You can also use database.new to create a new Supabase project.

2. Install agent skills (optional)#

Agent Skills are curated instruction sets that give your AI agent procedural knowledge about working with Supabase.

Install them in your project with:

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npx skills add supabase/agent-skills

3. Set up your database#

When your Supabase project is up and running, create an instruments table with some sample data. Then set only the privileges each Postgres role needs, add Row Level Security (RLS) for enhanced security for database data by default, and create an RLS policy to make the data in the table publicly readable.

Save some steps by clicking here to prefill the SQL in the SQL Editor, and then clicking Run.

Or do this manually in your project's SQL Editor, by pasting the SQL below, and clicking Run.

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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 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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-- Grant the privileges the role needs, which is read access
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grant select on public.instruments to anon;
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-- Enable row level security for the table
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alter table instruments enable row level security;
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-- Create a policy to allow the anon role to read from the instruments table
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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);

If you disabled the Data API during project setup, enable it in the Integrations > Data API section of the Dashboard and expose the specific tables or functions you want to access. To automatically grant access for new tables and functions in public, enable Automatically expose new tables.

4. Create an Android app with Android Studio#

Select the Android Studio > New > New Android Project menu item.

5. Install dependencies#

Open build.gradle.kts (app) file and add the serialization plugin, 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.

You can find the latest supabase-kt version on GitHub and Ktor in the Ktor documentation.

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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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}

6. 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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...

Get API details#

To interact with data in database tables, you use the client libraries that wrap the auto-generated Data API endpoints, authenticating using the Project URL and key from the project Connect dialog.

Project URL

Publishable key

Read the API keys docs for a full explanation of all key types, their uses, and where to find them.

7. Initialize the Supabase client#

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

For a quick example, create a client at the top of the MainActivity.kt file below the imports.

Replace the supabaseUrl and supabaseKey with your own, which you can get from the helper above, or from the project Connect panel:

Open Connect panel

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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_publishable_key"
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  ) {
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    install(Postgrest)
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}
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...

8. 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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)

9. 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.

This example application makes a network request from the UI code. In production, you should 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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}

10. Start the app#

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