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Quickstart: Kotlin (Android/JVM)

Build a real-time pub/sub app in 10 minutes.

Prerequisites​

Install​

Add to your build.gradle.kts:

dependencies {
    implementation("com.realtime:relay:1.1.0")
}

Basic Example​

import relay.Realtime
import relay.RealtimeConfig
import kotlinx.coroutines.runBlocking

fun main() = runBlocking {
    val config = RealtimeConfig().apply {
        apiKey = "your-api-key"
        secret = "your-secret"
    }

    val client = Realtime()
    client.init(config)
    await client.connect()

    // Subscribe to messages
    client.on("chat.room1") { msg ->
        println("${msg.data["user"]}: ${msg.data["text"]}")
    }

    // Publish a message
    client.publish("chat.room1", mapOf(
        "user" to "kotlin-user",
        "text" to "Hello from Kotlin!"
    ))

    println("Message sent!")
}

Android Example​

import relay.Realtime
import relay.RealtimeConfig
import kotlinx.coroutines.launch
import kotlinx.coroutines.CoroutineScope
import kotlinx.coroutines.Dispatchers

class ChatViewModel : ViewModel() {
    private val client = Realtime()

    fun connect(context: Context) {
        val config = RealtimeConfig().apply {
            apiKey = "your-api-key"
            secret = "your-secret"
            filesDir = context.filesDir
        }

        client.init(config)

        viewModelScope.launch {
            client.connect()

            client.on("chat.room1") { msg ->
                // Update UI with new message
                _messages.value += Message(
                    user = msg.data["user"] as String,
                    text = msg.data["text"] as String
                )
            }
        }
    }

    fun sendMessage(text: String) {
        viewModelScope.launch {
            client.publish("chat.room1", mapOf(
                "user" to "android-user",
                "text" to text
            ))
        }
    }
}

Run It​

  1. Add your API credentials
  2. Run the app
  3. Messages will appear in real-time