diff --git a/app/build.gradle.kts b/app/build.gradle.kts
index f5adcc9..dfb1006 100644
--- a/app/build.gradle.kts
+++ b/app/build.gradle.kts
@@ -106,6 +106,7 @@ dependencies {
 
     // Testing
     testImplementation("junit:junit:4.13.2")
+    testImplementation("io.mockk:mockk:1.13.12")
     testImplementation("org.jetbrains.kotlinx:kotlinx-coroutines-test:1.10.1")
     testImplementation("com.squareup.okhttp3:mockwebserver:4.12.0")
     testImplementation("app.cash.turbine:turbine:1.2.0")
diff --git a/app/src/main/AndroidManifest.xml b/app/src/main/AndroidManifest.xml
index de4254e..4af185e 100644
--- a/app/src/main/AndroidManifest.xml
+++ b/app/src/main/AndroidManifest.xml
@@ -5,6 +5,7 @@
     <uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
 
     <application
+        android:name=".HermesApplication"
         android:allowBackup="false"
         android:icon="@android:drawable/sym_def_app_icon"
         android:label="@string/app_name"
diff --git a/app/src/main/java/app/hermes/mobile/HermesAppContainer.kt b/app/src/main/java/app/hermes/mobile/HermesAppContainer.kt
new file mode 100644
index 0000000..1877a40
--- /dev/null
+++ b/app/src/main/java/app/hermes/mobile/HermesAppContainer.kt
@@ -0,0 +1,59 @@
+package app.hermes.mobile
+
+import android.content.Context
+import app.hermes.mobile.core.auth.PkceLoopbackAuthManager
+import app.hermes.mobile.core.network.HermesRestClient
+import app.hermes.mobile.core.repository.UnifiedSessionRepository
+import app.hermes.mobile.core.runtime.HermesConnectionManager
+import app.hermes.mobile.core.security.EncryptedTokenVault
+import app.hermes.mobile.core.storage.HermesDatabase
+import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.SupervisorJob
+
+interface AppContainer {
+    val db: HermesDatabase
+    val tokenVault: EncryptedTokenVault
+    val restClient: HermesRestClient
+    val pkceAuthManager: PkceLoopbackAuthManager
+    val connectionManager: HermesConnectionManager
+    val unifiedSessionRepo: UnifiedSessionRepository
+    val applicationScope: CoroutineScope
+}
+
+class HermesAppContainer(private val context: Context) : AppContainer {
+    override val applicationScope = CoroutineScope(SupervisorJob() + Dispatchers.Default)
+
+    override val db: HermesDatabase by lazy {
+        HermesDatabase.getInstance(context)
+    }
+
+    override val tokenVault: EncryptedTokenVault by lazy {
+        EncryptedTokenVault(context)
+    }
+
+    override val restClient: HermesRestClient by lazy {
+        HermesRestClient()
+    }
+
+    override val pkceAuthManager: PkceLoopbackAuthManager by lazy {
+        PkceLoopbackAuthManager(restClient, tokenVault)
+    }
+
+    override val connectionManager: HermesConnectionManager by lazy {
+        HermesConnectionManager(
+            hostDao = db.hostDao(),
+            tokenVault = tokenVault,
+            restClient = restClient,
+            scope = applicationScope
+        )
+    }
+
+    override val unifiedSessionRepo: UnifiedSessionRepository by lazy {
+        UnifiedSessionRepository(
+            connectionManager = connectionManager,
+            sessionDao = db.unifiedSessionDao(),
+            scope = applicationScope
+        )
+    }
+}
diff --git a/app/src/main/java/app/hermes/mobile/HermesApplication.kt b/app/src/main/java/app/hermes/mobile/HermesApplication.kt
new file mode 100644
index 0000000..77464ea
--- /dev/null
+++ b/app/src/main/java/app/hermes/mobile/HermesApplication.kt
@@ -0,0 +1,18 @@
+package app.hermes.mobile
+
+import android.app.Application
+import kotlinx.coroutines.cancel
+
+class HermesApplication : Application() {
+    lateinit var container: AppContainer
+
+    override fun onCreate() {
+        super.onCreate()
+        container = HermesAppContainer(this)
+    }
+
+    override fun onTerminate() {
+        super.onTerminate()
+        container.applicationScope.cancel()
+    }
+}
diff --git a/app/src/main/java/app/hermes/mobile/MainActivity.kt b/app/src/main/java/app/hermes/mobile/MainActivity.kt
index 6d0ae82..0a58df2 100644
--- a/app/src/main/java/app/hermes/mobile/MainActivity.kt
+++ b/app/src/main/java/app/hermes/mobile/MainActivity.kt
@@ -43,28 +43,19 @@ class MainActivity : ComponentActivity() {
         super.onCreate(savedInstanceState)
         enableEdgeToEdge()
 
-        val db = HermesDatabase.getInstance(applicationContext)
+        val container = (applicationContext as HermesApplication).container
+        
+        val db = container.db
         val hostDao = db.hostDao()
-        val sessionDao = db.unifiedSessionDao()
-        val tokenVault = EncryptedTokenVault(applicationContext)
-        val restClient = HermesRestClient()
-        val pkceAuthManager = PkceLoopbackAuthManager(restClient, tokenVault)
-
+        
         // Migrate legacy connections from DataStore if present
         lifecycleScope.launch {
             MigrationHelper.migrateLegacyConnections(applicationContext, hostDao)
         }
-
-        val connectionManager = HermesConnectionManager(
-            hostDao = hostDao,
-            tokenVault = tokenVault,
-            restClient = restClient
-        )
-
-        val unifiedSessionRepo = UnifiedSessionRepository(
-            connectionManager = connectionManager,
-            sessionDao = sessionDao
-        )
+        val tokenVault = container.tokenVault
+        val pkceAuthManager = container.pkceAuthManager
+        val connectionManager = container.connectionManager
+        val unifiedSessionRepo = container.unifiedSessionRepo
 
         setContent {
             HermesAndroidTheme {
diff --git a/app/src/main/java/app/hermes/mobile/core/network/JsonRpcGatewayClient.kt b/app/src/main/java/app/hermes/mobile/core/network/JsonRpcGatewayClient.kt
index c48ef0d..c8c9ec4 100644
--- a/app/src/main/java/app/hermes/mobile/core/network/JsonRpcGatewayClient.kt
+++ b/app/src/main/java/app/hermes/mobile/core/network/JsonRpcGatewayClient.kt
@@ -77,7 +77,7 @@ class JsonRpcGatewayClient(
     private val _connectionState = MutableStateFlow<ConnectionState>(ConnectionState.Disconnected)
     val connectionState: StateFlow<ConnectionState> = _connectionState.asStateFlow()
 
-    private val _events = MutableSharedFlow<GatewayEvent>(replay = 1, extraBufferCapacity = 64)
+    private val _events = MutableSharedFlow<GatewayEvent>(extraBufferCapacity = 64)
     val events: SharedFlow<GatewayEvent> = _events.asSharedFlow()
 
     private fun nextId(): String = "a${reqCounter.incrementAndGet()}"
diff --git a/app/src/main/java/app/hermes/mobile/core/runtime/HermesConnectionManager.kt b/app/src/main/java/app/hermes/mobile/core/runtime/HermesConnectionManager.kt
index a139a97..b3192c9 100644
--- a/app/src/main/java/app/hermes/mobile/core/runtime/HermesConnectionManager.kt
+++ b/app/src/main/java/app/hermes/mobile/core/runtime/HermesConnectionManager.kt
@@ -26,13 +26,14 @@ class HermesConnectionManager(
     val tokenVault: TokenVault,
     val restClient: HermesRestClient = HermesRestClient(),
     val scope: CoroutineScope = CoroutineScope(SupervisorJob() + Dispatchers.Default),
-    val runtimeFactory: (HermesHost) -> HermesHostRuntime = { host ->
+    val runtimeFactory: (CoroutineScope, HermesHost) -> HermesHostRuntime = { parentScope, host ->
+        val childScope = CoroutineScope(SupervisorJob(parentScope.coroutineContext[kotlinx.coroutines.Job]) + Dispatchers.Default)
         HermesHostRuntime(
             initialHost = host,
             restClient = restClient,
-            gatewayClient = JsonRpcGatewayClient(scope = scope),
+            gatewayClient = JsonRpcGatewayClient(scope = childScope),
             tokenVault = tokenVault,
-            scope = scope
+            scope = childScope
         )
     }
 ) {
@@ -44,7 +45,7 @@ class HermesConnectionManager(
     private val _activeHostId = MutableStateFlow<HermesHostId?>(null)
     val activeHostId: StateFlow<HermesHostId?> = _activeHostId.asStateFlow()
 
-    private val _allEvents = MutableSharedFlow<HostGatewayEvent>(replay = 1, extraBufferCapacity = 128)
+    private val _allEvents = MutableSharedFlow<HostGatewayEvent>(extraBufferCapacity = 128)
     val allEvents: SharedFlow<HostGatewayEvent> = _allEvents.asSharedFlow()
 
     init {
@@ -89,7 +90,7 @@ class HermesConnectionManager(
 
     fun getOrCreateRuntime(host: HermesHost): HermesHostRuntime {
         return runtimes.computeIfAbsent(host.id) {
-            val rt = runtimeFactory(host)
+            val rt = runtimeFactory(scope, host)
             // Forward events
             scope.launch {
                 rt.events.collect { event ->
diff --git a/app/src/test/java/app/hermes/mobile/core/network/EventStreamReplayTest.kt b/app/src/test/java/app/hermes/mobile/core/network/EventStreamReplayTest.kt
new file mode 100644
index 0000000..88c2e82
--- /dev/null
+++ b/app/src/test/java/app/hermes/mobile/core/network/EventStreamReplayTest.kt
@@ -0,0 +1,44 @@
+package app.hermes.mobile.core.network
+
+import app.hermes.mobile.core.model.GatewayEvent
+import app.hermes.mobile.core.model.GatewayEvent.MessageDeltaEvent
+import kotlinx.coroutines.flow.firstOrNull
+import kotlinx.coroutines.flow.toList
+import kotlinx.coroutines.launch
+import kotlinx.coroutines.test.UnconfinedTestDispatcher
+import kotlinx.coroutines.test.runTest
+import kotlinx.coroutines.test.runCurrent
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+class EventStreamReplayTest {
+
+    @Test
+    fun testNoReplay() = runTest {
+        val client = JsonRpcGatewayClient(scope = this)
+        
+        // Emit first event BEFORE subscribing
+        client.handleIncomingMessage("{\"jsonrpc\":\"2.0\",\"method\":\"event\",\"params\":{\"type\":\"message.delta\",\"session_id\":\"s1\",\"payload\":{\"message_id\":\"m1\",\"delta\":\"Hello\"}}}")
+        runCurrent()
+        
+        val events = mutableListOf<GatewayEvent>()
+        val job = launch {
+            client.events.collect { events.add(it) }
+        }
+        runCurrent()
+        
+        // Should not have received the first event
+        assertTrue("Events should be empty since we subscribed after the first emission", events.isEmpty())
+        
+        // Emit second event AFTER subscribing
+        client.handleIncomingMessage("{\"jsonrpc\":\"2.0\",\"method\":\"event\",\"params\":{\"type\":\"message.delta\",\"session_id\":\"s1\",\"payload\":{\"message_id\":\"m1\",\"delta\":\" World\"}}}")
+        runCurrent()
+        
+        assertEquals("Should have exactly 1 event", 1, events.size)
+        val event = events[0] as GatewayEvent.MessageDeltaEvent
+        assertEquals(" World", event.delta)
+        
+        job.cancel()
+    }
+}
diff --git a/app/src/test/java/app/hermes/mobile/core/network/JsonRpcGatewayClientTest.kt b/app/src/test/java/app/hermes/mobile/core/network/JsonRpcGatewayClientTest.kt
index 6bd99a5..b81066c 100644
--- a/app/src/test/java/app/hermes/mobile/core/network/JsonRpcGatewayClientTest.kt
+++ b/app/src/test/java/app/hermes/mobile/core/network/JsonRpcGatewayClientTest.kt
@@ -6,6 +6,9 @@ import app.hermes.mobile.core.model.RuntimeSessionId
 import kotlinx.coroutines.flow.first
 import kotlinx.coroutines.runBlocking
 import kotlinx.coroutines.withTimeout
+import kotlinx.coroutines.async
+import kotlinx.coroutines.CoroutineStart
+import kotlinx.coroutines.async
 import okhttp3.Response
 import okhttp3.WebSocket
 import okhttp3.WebSocketListener
@@ -123,12 +126,18 @@ class JsonRpcGatewayClientTest {
         )
 
         val wsUrl = "ws://${server.hostName}:${server.port}/api/ws"
+        
+        // Start subscription BEFORE connecting, so we don't miss the event
+        val eventDeferred = async(start = CoroutineStart.UNDISPATCHED) {
+            withTimeout(5000) {
+                client.events.first { it is GatewayEvent.MessageDeltaEvent }
+            }
+        }
+        
         client.connect(wsUrl, allowCleartext = true)
         client.awaitGatewayReady(5000)
 
-        val event = withTimeout(5000) {
-            client.events.first { it is GatewayEvent.MessageDeltaEvent }
-        }
+        val event = eventDeferred.await()
 
         assertTrue(event is GatewayEvent.MessageDeltaEvent)
         val deltaEvent = event as GatewayEvent.MessageDeltaEvent
diff --git a/app/src/test/java/app/hermes/mobile/core/repository/ApprovalRoutingTest.kt b/app/src/test/java/app/hermes/mobile/core/repository/ApprovalRoutingTest.kt
index 28c92d4..8f22b2b 100644
--- a/app/src/test/java/app/hermes/mobile/core/repository/ApprovalRoutingTest.kt
+++ b/app/src/test/java/app/hermes/mobile/core/repository/ApprovalRoutingTest.kt
@@ -59,7 +59,17 @@ class ApprovalRoutingTest {
         connectionManager = HermesConnectionManager(
             hostDao = hostDao,
             tokenVault = tokenVault,
-            scope = CoroutineScope(testDispatcher)
+            scope = CoroutineScope(testDispatcher),
+            runtimeFactory = { parentScope, host ->
+                val childScope = CoroutineScope(kotlinx.coroutines.SupervisorJob(parentScope.coroutineContext[kotlinx.coroutines.Job]) + testDispatcher)
+                HermesHostRuntime(
+                    initialHost = host,
+                    restClient = app.hermes.mobile.core.network.HermesRestClient(),
+                    gatewayClient = JsonRpcGatewayClient(scope = childScope),
+                    tokenVault = tokenVault,
+                    scope = childScope
+                )
+            }
         )
 
         sessionRepo = UnifiedSessionRepository(
diff --git a/app/src/test/java/app/hermes/mobile/core/repository/MultiHostConcurrencyExecutionTest.kt b/app/src/test/java/app/hermes/mobile/core/repository/MultiHostConcurrencyExecutionTest.kt
index 5e68732..6fbfda9 100644
--- a/app/src/test/java/app/hermes/mobile/core/repository/MultiHostConcurrencyExecutionTest.kt
+++ b/app/src/test/java/app/hermes/mobile/core/repository/MultiHostConcurrencyExecutionTest.kt
@@ -3,6 +3,7 @@ package app.hermes.mobile.core.repository
 import app.hermes.mobile.core.model.*
 import app.hermes.mobile.core.network.ConnectionState
 import app.hermes.mobile.core.network.JsonRpcGatewayClient
+import app.hermes.mobile.core.network.HermesRestClient
 import app.hermes.mobile.core.runtime.HermesConnectionManager
 import app.hermes.mobile.core.runtime.HermesHostRuntime
 import app.hermes.mobile.core.security.InMemoryTokenVault
@@ -53,7 +54,17 @@ class MultiHostConcurrencyExecutionTest {
         connectionManager = HermesConnectionManager(
             hostDao = hostDao,
             tokenVault = tokenVault,
-            scope = CoroutineScope(testDispatcher)
+            scope = CoroutineScope(testDispatcher),
+            runtimeFactory = { parentScope, host ->
+                val childScope = CoroutineScope(kotlinx.coroutines.SupervisorJob(parentScope.coroutineContext[kotlinx.coroutines.Job]) + testDispatcher)
+                app.hermes.mobile.core.runtime.HermesHostRuntime(
+                    initialHost = host,
+                    restClient = app.hermes.mobile.core.network.HermesRestClient(),
+                    gatewayClient = app.hermes.mobile.core.network.JsonRpcGatewayClient(scope = childScope),
+                    tokenVault = tokenVault,
+                    scope = childScope
+                )
+            }
         )
 
         sessionRepo = UnifiedSessionRepository(
@@ -664,8 +675,10 @@ class MultiHostConcurrencyExecutionTest {
             scope = CoroutineScope(Dispatchers.Default)
         )
 
-        val session = testRepo.createUnifiedSession(title = "Reconnect Test", initialHostId = host1Id)
-        val runtime = testConnectionManager.getRuntime(host1Id)!!
+        val host1 = HermesHost(id = HermesHostId("host-windows"), displayName = "Server", baseUrl = wsUrl, allowCleartext = true, lastKnownStatus = HostStatus.ONLINE)
+        testConnectionManager.addHost(host1)
+        val session = testRepo.createUnifiedSession(title = "Reconnect Test", initialHostId = HermesHostId("host-windows"))
+        val runtime = testConnectionManager.getRuntime(HermesHostId("host-windows"))!!
 
         // Initial connect
         runtime.connect()
diff --git a/app/src/test/java/app/hermes/mobile/core/repository/UnifiedSessionRepositoryTest.kt b/app/src/test/java/app/hermes/mobile/core/repository/UnifiedSessionRepositoryTest.kt
index ea4b7ff..fe3b1df 100644
--- a/app/src/test/java/app/hermes/mobile/core/repository/UnifiedSessionRepositoryTest.kt
+++ b/app/src/test/java/app/hermes/mobile/core/repository/UnifiedSessionRepositoryTest.kt
@@ -5,6 +5,7 @@ import app.hermes.mobile.core.network.ConnectionState
 import app.hermes.mobile.core.network.HermesRestClient
 import app.hermes.mobile.core.network.JsonRpcGatewayClient
 import app.hermes.mobile.core.runtime.HermesConnectionManager
+import app.hermes.mobile.core.runtime.HermesHostRuntime
 import app.hermes.mobile.core.security.InMemoryTokenVault
 import app.hermes.mobile.core.storage.FakeHostDao
 import app.hermes.mobile.core.storage.FakeUnifiedSessionDao
@@ -49,7 +50,17 @@ class UnifiedSessionRepositoryTest {
         connectionManager = HermesConnectionManager(
             hostDao = hostDao,
             tokenVault = tokenVault,
-            scope = CoroutineScope(testDispatcher)
+            scope = CoroutineScope(testDispatcher),
+            runtimeFactory = { parentScope, host ->
+                val childScope = CoroutineScope(kotlinx.coroutines.SupervisorJob(parentScope.coroutineContext[kotlinx.coroutines.Job]) + testDispatcher)
+                app.hermes.mobile.core.runtime.HermesHostRuntime(
+                    initialHost = host,
+                    restClient = app.hermes.mobile.core.network.HermesRestClient(),
+                    gatewayClient = app.hermes.mobile.core.network.JsonRpcGatewayClient(scope = childScope),
+                    tokenVault = tokenVault,
+                    scope = childScope
+                )
+            }
         )
 
         repository = UnifiedSessionRepository(
diff --git a/app/src/test/java/app/hermes/mobile/core/runtime/AppLifecycleTest.kt b/app/src/test/java/app/hermes/mobile/core/runtime/AppLifecycleTest.kt
new file mode 100644
index 0000000..3d47f62
--- /dev/null
+++ b/app/src/test/java/app/hermes/mobile/core/runtime/AppLifecycleTest.kt
@@ -0,0 +1,55 @@
+package app.hermes.mobile.core.runtime
+
+import app.hermes.mobile.core.model.HermesHost
+import app.hermes.mobile.core.model.HermesHostId
+import app.hermes.mobile.core.model.HostStatus
+import app.hermes.mobile.core.network.HermesRestClient
+import app.hermes.mobile.core.security.InMemoryTokenVault
+import app.hermes.mobile.core.storage.FakeHostDao
+import kotlinx.coroutines.test.runTest
+import org.junit.Assert.assertSame
+import org.junit.Test
+
+class AppLifecycleTest {
+
+    @Test
+    fun testSingleHostIdCorrespondsToAtMostOneLiveRuntime() = runTest {
+        val hostDao = FakeHostDao()
+        val tokenVault = InMemoryTokenVault()
+        val restClient = HermesRestClient()
+        
+        val connectionManager = HermesConnectionManager(
+            hostDao = hostDao,
+            tokenVault = tokenVault,
+            restClient = restClient,
+            scope = backgroundScope,
+            runtimeFactory = { parentScope, host ->
+                val childScope = kotlinx.coroutines.CoroutineScope(kotlinx.coroutines.SupervisorJob(parentScope.coroutineContext[kotlinx.coroutines.Job]) + kotlinx.coroutines.test.StandardTestDispatcher(testScheduler))
+                app.hermes.mobile.core.runtime.HermesHostRuntime(
+                    initialHost = host,
+                    restClient = restClient,
+                    gatewayClient = app.hermes.mobile.core.network.JsonRpcGatewayClient(scope = childScope),
+                    tokenVault = tokenVault,
+                    scope = childScope
+                )
+            }
+        )
+        
+        val host = HermesHost(
+            id = HermesHostId("h1"),
+            displayName = "Host 1",
+            baseUrl = "http://host1.com",
+            allowCleartext = true,
+            enabled = true,
+            lastSeenAt = 0L,
+            lastKnownStatus = HostStatus.OFFLINE
+        )
+        
+        val runtime1 = connectionManager.getOrCreateRuntime(host)
+        val runtime2 = connectionManager.getOrCreateRuntime(host)
+        val runtime3 = connectionManager.getRuntime(host.id)
+        
+        assertSame(runtime1, runtime2)
+        assertSame(runtime1, runtime3)
+    }
+}