diff --git a/metarouter-sdk/src/main/java/com/metarouter/analytics/identity/IdentityManager.kt b/metarouter-sdk/src/main/java/com/metarouter/analytics/identity/IdentityManager.kt
index 165860e..98f1027 100644
--- a/metarouter-sdk/src/main/java/com/metarouter/analytics/identity/IdentityManager.kt
+++ b/metarouter-sdk/src/main/java/com/metarouter/analytics/identity/IdentityManager.kt
@@ -83,4 +83,11 @@ class IdentityManager(
         storage.clear()
         Logger.log("Identity manager reset")
     }
+
+    /**
+     * Returns true if identity storage already has any value. Used by lifecycle-event
+     * detection to tell a true fresh install from a user upgrading from a pre-lifecycle
+     * SDK build (where the version/build keys would be missing despite prior usage).
+     */
+    fun hasAnyValue(): Boolean = storage.hasAnyValue()
 }
diff --git a/metarouter-sdk/src/main/java/com/metarouter/analytics/lifecycle/LifecycleEventNames.kt b/metarouter-sdk/src/main/java/com/metarouter/analytics/lifecycle/LifecycleEventNames.kt
new file mode 100644
index 0000000..db65a64
--- /dev/null
+++ b/metarouter-sdk/src/main/java/com/metarouter/analytics/lifecycle/LifecycleEventNames.kt
@@ -0,0 +1,28 @@
+package com.metarouter.analytics.lifecycle
+
+/**
+ * Centralized event-name constants for the four application-lifecycle events.
+ * Single source of truth shared by the tracker (emission) and any future
+ * coordinator / observer wiring.
+ */
+internal object LifecycleEventNames {
+    const val INSTALLED = "Application Installed"
+    const val UPDATED = "Application Updated"
+    const val OPENED = "Application Opened"
+    const val BACKGROUNDED = "Application Backgrounded"
+}
+
+/**
+ * Centralized property-name constants for lifecycle event payloads.
+ */
+internal object LifecycleEventProperties {
+    const val VERSION = "version"
+    const val BUILD = "build"
+    const val PREVIOUS_VERSION = "previous_version"
+    const val PREVIOUS_BUILD = "previous_build"
+    const val FROM_BACKGROUND = "from_background"
+    const val URL = "url"
+    const val REFERRING_APPLICATION = "referring_application"
+}
+
+internal const val LIFECYCLE_UNKNOWN = "unknown"
diff --git a/metarouter-sdk/src/main/java/com/metarouter/analytics/storage/IdentityStorage.kt b/metarouter-sdk/src/main/java/com/metarouter/analytics/storage/IdentityStorage.kt
index eeeb9d2..2b5a508 100644
--- a/metarouter-sdk/src/main/java/com/metarouter/analytics/storage/IdentityStorage.kt
+++ b/metarouter-sdk/src/main/java/com/metarouter/analytics/storage/IdentityStorage.kt
@@ -15,6 +15,17 @@ class IdentityStorage(context: Context) {
 
     fun get(key: String): String? = prefs.getString(key, null)
 
+    /**
+     * Returns true if any identity-related key is currently set in storage.
+     * Used to distinguish a fresh install from an upgrade that pre-dates lifecycle tracking.
+     */
+    fun hasAnyValue(): Boolean {
+        return prefs.contains(KEY_ANONYMOUS_ID) ||
+            prefs.contains(KEY_USER_ID) ||
+            prefs.contains(KEY_GROUP_ID) ||
+            prefs.contains(KEY_ADVERTISING_ID)
+    }
+
     /**
      * Store a value asynchronously (non-blocking).
      * The write is guaranteed to be ordered with other apply() calls and will persist.
diff --git a/metarouter-sdk/src/main/java/com/metarouter/analytics/storage/LifecycleStorage.kt b/metarouter-sdk/src/main/java/com/metarouter/analytics/storage/LifecycleStorage.kt
new file mode 100644
index 0000000..ced0ac1
--- /dev/null
+++ b/metarouter-sdk/src/main/java/com/metarouter/analytics/storage/LifecycleStorage.kt
@@ -0,0 +1,36 @@
+package com.metarouter.analytics.storage
+
+import android.content.Context
+
+/**
+ * Persistent storage for the last-seen app `version` and `build`.
+ *
+ * Lives in a dedicated `SharedPreferences` file so [IdentityStorage.clear]
+ * (and `MetaRouterAnalyticsClient.reset()`) cannot wipe install/update state.
+ */
+class LifecycleStorage(context: Context) {
+
+    private val prefs = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
+
+    fun getVersion(): String? = prefs.getString(KEY_VERSION, null)
+
+    fun getBuild(): String? = prefs.getString(KEY_BUILD, null)
+
+    fun setVersionBuild(version: String, build: String) {
+        prefs.edit()
+            .putString(KEY_VERSION, version)
+            .putString(KEY_BUILD, build)
+            .apply()
+    }
+
+    fun clear() {
+        prefs.edit().clear().apply()
+    }
+
+    companion object {
+        private const val PREFS_NAME = "com.metarouter.analytics.lifecycle"
+
+        const val KEY_VERSION = "metarouter:lifecycle:version"
+        const val KEY_BUILD = "metarouter:lifecycle:build"
+    }
+}
diff --git a/metarouter-sdk/src/main/java/com/metarouter/analytics/types/EventContext.kt b/metarouter-sdk/src/main/java/com/metarouter/analytics/types/EventContext.kt
index 80f83e3..32dae9b 100644
--- a/metarouter-sdk/src/main/java/com/metarouter/analytics/types/EventContext.kt
+++ b/metarouter-sdk/src/main/java/com/metarouter/analytics/types/EventContext.kt
@@ -1,5 +1,9 @@
 package com.metarouter.analytics.types
 
+import android.content.Context
+import android.content.pm.PackageManager
+import android.os.Build
+import com.metarouter.analytics.utils.Logger
 import kotlinx.serialization.Serializable
 
 /**
@@ -27,7 +31,70 @@ data class AppContext(
     val version: String,
     val build: String,
     val namespace: String
-)
+) {
+    companion object {
+        private const val UNKNOWN = "unknown"
+
+        /**
+         * Read app metadata from `PackageManager` once. Safe to cache for the
+         * process lifetime — the manifest values are immutable post-install.
+         *
+         * Both the lifecycle subsystem and `DeviceContextProvider` consume this
+         * cached snapshot so per-event enrichment does not re-read the manifest.
+         */
+        fun fromContext(context: Context): AppContext {
+            return try {
+                val packageManager = context.packageManager
+                val packageName = context.packageName
+                val packageInfo = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+                    packageManager.getPackageInfo(packageName, PackageManager.PackageInfoFlags.of(0))
+                } else {
+                    @Suppress("DEPRECATION")
+                    packageManager.getPackageInfo(packageName, 0)
+                }
+
+                val appName = try {
+                    packageInfo.applicationInfo?.let {
+                        packageManager.getApplicationLabel(it).toString()
+                    } ?: UNKNOWN
+                } catch (e: Exception) {
+                    UNKNOWN
+                }
+
+                val versionName = packageInfo.versionName ?: UNKNOWN
+                val versionCode = if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.P) {
+                    packageInfo.longVersionCode.toString()
+                } else {
+                    @Suppress("DEPRECATION")
+                    packageInfo.versionCode.toString()
+                }
+
+                AppContext(
+                    name = appName,
+                    version = versionName,
+                    build = versionCode,
+                    namespace = packageName
+                )
+            } catch (e: Exception) {
+                Logger.warn("Failed to read AppContext from PackageManager: ${e.message}")
+                // Derive a best-effort `name` from the package's last segment when the
+                // PackageManager read fails entirely. Better than literal "unknown" on
+                // ingest dashboards and matches what most launchers show when the
+                // applicationLabel resolution itself fails.
+                val packageName = context.packageName
+                val derivedName = packageName.substringAfterLast('.')
+                    .takeIf { it.isNotBlank() }
+                    ?: UNKNOWN
+                AppContext(
+                    name = derivedName,
+                    version = UNKNOWN,
+                    build = UNKNOWN,
+                    namespace = packageName
+                )
+            }
+        }
+    }
+}
 
 /**
  * Device information including manufacturer, model, device name, and type.
diff --git a/metarouter-sdk/src/test/java/com/metarouter/analytics/storage/LifecycleStorageTest.kt b/metarouter-sdk/src/test/java/com/metarouter/analytics/storage/LifecycleStorageTest.kt
new file mode 100644
index 0000000..45e35a7
--- /dev/null
+++ b/metarouter-sdk/src/test/java/com/metarouter/analytics/storage/LifecycleStorageTest.kt
@@ -0,0 +1,113 @@
+package com.metarouter.analytics.storage
+
+import android.content.Context
+import androidx.test.core.app.ApplicationProvider
+import org.junit.After
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertNull
+import org.junit.Before
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+
+@RunWith(RobolectricTestRunner::class)
+class LifecycleStorageTest {
+
+    private lateinit var context: Context
+    private lateinit var storage: LifecycleStorage
+    private lateinit var identityStorage: IdentityStorage
+
+    @Before
+    fun setup() {
+        context = ApplicationProvider.getApplicationContext()
+        storage = LifecycleStorage(context)
+        identityStorage = IdentityStorage(context)
+        storage.clear()
+        identityStorage.clear()
+    }
+
+    @After
+    fun tearDown() {
+        storage.clear()
+        identityStorage.clear()
+    }
+
+    @Test
+    fun `get returns null when not set`() {
+        assertNull(storage.getVersion())
+        assertNull(storage.getBuild())
+    }
+
+    @Test
+    fun `setVersionBuild persists both fields`() {
+        storage.setVersionBuild("1.4.0", "42")
+
+        assertEquals("1.4.0", storage.getVersion())
+        assertEquals("42", storage.getBuild())
+    }
+
+    @Test
+    fun `setVersionBuild overwrites previous values`() {
+        storage.setVersionBuild("1.0.0", "1")
+        storage.setVersionBuild("2.0.0", "2")
+
+        assertEquals("2.0.0", storage.getVersion())
+        assertEquals("2", storage.getBuild())
+    }
+
+    @Test
+    fun `data persists across instances`() {
+        storage.setVersionBuild("1.4.0", "42")
+
+        val storage2 = LifecycleStorage(context)
+        assertEquals("1.4.0", storage2.getVersion())
+        assertEquals("42", storage2.getBuild())
+    }
+
+    @Test
+    fun `lifecycle storage is independent of identity storage clear`() {
+        storage.setVersionBuild("1.4.0", "42")
+        identityStorage.set(IdentityStorage.KEY_ANONYMOUS_ID, "anon-id")
+        identityStorage.set(IdentityStorage.KEY_USER_ID, "user-id")
+
+        // Clearing identity storage must NOT touch lifecycle storage
+        identityStorage.clear()
+
+        assertNull(identityStorage.get(IdentityStorage.KEY_ANONYMOUS_ID))
+        assertNull(identityStorage.get(IdentityStorage.KEY_USER_ID))
+        assertEquals("1.4.0", storage.getVersion())
+        assertEquals("42", storage.getBuild())
+    }
+
+    @Test
+    fun `keys match cross-platform contract`() {
+        assertEquals("metarouter:lifecycle:version", LifecycleStorage.KEY_VERSION)
+        assertEquals("metarouter:lifecycle:build", LifecycleStorage.KEY_BUILD)
+    }
+
+    @Test
+    fun `clear removes both fields`() {
+        storage.setVersionBuild("1.4.0", "42")
+
+        storage.clear()
+
+        assertNull(storage.getVersion())
+        assertNull(storage.getBuild())
+    }
+
+    @Test
+    fun `identityStorage hasAnyValue reflects whether keys exist`() {
+        // Empty initially
+        assertEquals(false, identityStorage.hasAnyValue())
+
+        identityStorage.set(IdentityStorage.KEY_ANONYMOUS_ID, "anon")
+        assertEquals(true, identityStorage.hasAnyValue())
+
+        identityStorage.clear()
+        assertEquals(false, identityStorage.hasAnyValue())
+
+        identityStorage.set(IdentityStorage.KEY_USER_ID, "user")
+        assertEquals(true, identityStorage.hasAnyValue())
+    }
+}
diff --git a/metarouter-sdk/src/test/java/com/metarouter/analytics/types/AppContextTest.kt b/metarouter-sdk/src/test/java/com/metarouter/analytics/types/AppContextTest.kt
new file mode 100644
index 0000000..a1e6b3b
--- /dev/null
+++ b/metarouter-sdk/src/test/java/com/metarouter/analytics/types/AppContextTest.kt
@@ -0,0 +1,57 @@
+package com.metarouter.analytics.types
+
+import android.content.Context
+import androidx.test.core.app.ApplicationProvider
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+import org.junit.runner.RunWith
+import org.robolectric.RobolectricTestRunner
+
+/**
+ * Smoke coverage for the `AppContext.fromContext` factory. The full `DeviceContextProvider`
+ * test exercises this transitively, but this slice introduces the factory standalone and
+ * deserves direct coverage.
+ */
+@RunWith(RobolectricTestRunner::class)
+class AppContextTest {
+
+    @Test
+    fun `fromContext populates namespace from package`() {
+        val ctx: Context = ApplicationProvider.getApplicationContext()
+        val app = AppContext.fromContext(ctx)
+
+        assertEquals(ctx.packageName, app.namespace)
+    }
+
+    @Test
+    fun `fromContext returns non-blank fields`() {
+        val ctx: Context = ApplicationProvider.getApplicationContext()
+        val app = AppContext.fromContext(ctx)
+
+        assertTrue("name should not be blank", app.name.isNotBlank())
+        assertTrue("version should not be blank", app.version.isNotBlank())
+        assertTrue("build should not be blank", app.build.isNotBlank())
+        assertTrue("namespace should not be blank", app.namespace.isNotBlank())
+    }
+
+    @Test
+    fun `fromContext is stable across calls`() {
+        val ctx: Context = ApplicationProvider.getApplicationContext()
+        val first = AppContext.fromContext(ctx)
+        val second = AppContext.fromContext(ctx)
+
+        assertEquals(first, second)
+    }
+
+    @Test
+    fun `equality is structural`() {
+        val a = AppContext("App", "1.0", "100", "com.example")
+        val b = AppContext("App", "1.0", "100", "com.example")
+        val c = AppContext("App", "1.1", "100", "com.example")
+
+        assertEquals(a, b)
+        assertNotEquals(a, c)
+    }
+}