diff --git a/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/CoreModule.kt b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/CoreModule.kt
index afac786ad6..efc06d54a4 100644
--- a/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/CoreModule.kt
+++ b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/CoreModule.kt
@@ -13,7 +13,9 @@ import com.onesignal.core.internal.config.impl.ConfigModelStoreListener
 import com.onesignal.core.internal.database.IDatabaseProvider
 import com.onesignal.core.internal.database.impl.DatabaseProvider
 import com.onesignal.core.internal.device.IDeviceService
+import com.onesignal.core.internal.device.IInstallIdService
 import com.onesignal.core.internal.device.impl.DeviceService
+import com.onesignal.core.internal.device.impl.InstallIdService
 import com.onesignal.core.internal.http.IHttpClient
 import com.onesignal.core.internal.http.impl.HttpClient
 import com.onesignal.core.internal.http.impl.HttpConnectionFactory
@@ -53,6 +55,7 @@ internal class CoreModule : IModule {
         builder.register<Time>().provides<ITime>()
         builder.register<DatabaseProvider>().provides<IDatabaseProvider>()
         builder.register<StartupService>().provides<StartupService>()
+        builder.register<InstallIdService>().provides<IInstallIdService>()
 
         // Params (Config)
         builder.register<ConfigModelStore>().provides<ConfigModelStore>()
diff --git a/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/device/IInstallIdService.kt b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/device/IInstallIdService.kt
new file mode 100644
index 0000000000..ed49d4200c
--- /dev/null
+++ b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/device/IInstallIdService.kt
@@ -0,0 +1,11 @@
+package com.onesignal.core.internal.device
+
+import java.util.UUID
+
+interface IInstallIdService {
+    /**
+     * WARNING: This may do disk I/O on the first call, so never call this from
+     * the main thread.
+     */
+    suspend fun getId(): UUID
+}
diff --git a/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/device/impl/InstallIdService.kt b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/device/impl/InstallIdService.kt
new file mode 100644
index 0000000000..bf58c52c43
--- /dev/null
+++ b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/device/impl/InstallIdService.kt
@@ -0,0 +1,35 @@
+package com.onesignal.core.internal.device.impl
+
+import com.onesignal.core.internal.device.IInstallIdService
+import com.onesignal.core.internal.preferences.IPreferencesService
+import com.onesignal.core.internal.preferences.PreferenceOneSignalKeys
+import com.onesignal.core.internal.preferences.PreferenceStores
+import java.util.UUID
+
+/**
+ * Manages a persistent UUIDv4, generated once when app is first opened.
+ * Value is for a HTTP header, OneSignal-Install-Id, added on all calls made
+ * to OneSignal's backend. This allows the OneSignal's backend know where
+ * traffic is coming from, no matter if the SubscriptionId or OneSignalId
+ * changes or isn't available yet.
+ */
+internal class InstallIdService(
+    private val _prefs: IPreferencesService,
+) : IInstallIdService {
+    private val currentId: UUID by lazy {
+        val idFromPrefs = _prefs.getString(PreferenceStores.ONESIGNAL, PreferenceOneSignalKeys.PREFS_OS_INSTALL_ID)
+        if (idFromPrefs != null) {
+            UUID.fromString(idFromPrefs)
+        } else {
+            val newId = UUID.randomUUID()
+            _prefs.saveString(PreferenceStores.ONESIGNAL, PreferenceOneSignalKeys.PREFS_OS_INSTALL_ID, newId.toString())
+            newId
+        }
+    }
+
+    /**
+     * WARNING: This may do disk I/O on the first call, so never call this from
+     * the main thread. Disk I/O is done inside of "currentId by lazy".
+     */
+    override suspend fun getId() = currentId
+}
diff --git a/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/http/impl/HttpClient.kt b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/http/impl/HttpClient.kt
index 5fbbbbc78a..a3827cb19b 100644
--- a/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/http/impl/HttpClient.kt
+++ b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/http/impl/HttpClient.kt
@@ -6,6 +6,7 @@ import com.onesignal.common.JSONUtils
 import com.onesignal.common.OneSignalUtils
 import com.onesignal.common.OneSignalWrapper
 import com.onesignal.core.internal.config.ConfigModelStore
+import com.onesignal.core.internal.device.IInstallIdService
 import com.onesignal.core.internal.http.HttpResponse
 import com.onesignal.core.internal.http.IHttpClient
 import com.onesignal.core.internal.preferences.IPreferencesService
@@ -23,6 +24,7 @@ import kotlinx.coroutines.withTimeout
 import org.json.JSONObject
 import java.net.ConnectException
 import java.net.HttpURLConnection
+import java.net.URL
 import java.net.UnknownHostException
 import java.util.Scanner
 import javax.net.ssl.HttpsURLConnection
@@ -32,6 +34,7 @@ internal class HttpClient(
     private val _prefs: IPreferencesService,
     private val _configModelStore: ConfigModelStore,
     private val _time: ITime,
+    private val _installIdService: IInstallIdService,
 ) : IHttpClient {
     /**
      * Delay making network requests until we reach this time.
@@ -149,6 +152,8 @@ internal class HttpClient(
                         con.setRequestProperty("OneSignal-Subscription-Id", subscriptionId)
                     }
 
+                    con.setRequestProperty("OneSignal-Install-Id", _installIdService.getId().toString())
+
                     if (jsonBody != null) {
                         con.doInput = true
                     }
@@ -159,16 +164,14 @@ internal class HttpClient(
                         con.doOutput = true
                     }
 
+                    logHTTPSent(con.requestMethod, con.url, jsonBody, con.requestProperties)
+
                     if (jsonBody != null) {
                         val strJsonBody = JSONUtils.toUnescapedEUIDString(jsonBody)
-                        Logging.debug("HttpClient: ${method ?: "GET"} $url - $strJsonBody")
-
                         val sendBytes = strJsonBody.toByteArray(charset("UTF-8"))
                         con.setFixedLengthStreamingMode(sendBytes.size)
                         val outputStream = con.outputStream
                         outputStream.write(sendBytes)
-                    } else {
-                        Logging.debug("HttpClient: ${method ?: "GET"} $url")
                     }
 
                     if (cacheKey != null) {
@@ -194,7 +197,7 @@ internal class HttpClient(
                                     PreferenceStores.ONESIGNAL,
                                     PreferenceOneSignalKeys.PREFS_OS_HTTP_CACHE_PREFIX + cacheKey,
                                 )
-                            Logging.debug("HttpClient: ${method ?: "GET"} $url - Using Cached response due to 304: " + cachedResponse)
+                            Logging.debug("HttpClient: Got Response = ${method ?: "GET"} ${con.url} - Using Cached response due to 304: " + cachedResponse)
 
                             // TODO: SHOULD RETURN OK INSTEAD OF NOT_MODIFIED TO MAKE TRANSPARENT?
                             retVal = HttpResponse(httpResponse, cachedResponse, retryAfterSeconds = retryAfter)
@@ -204,12 +207,12 @@ internal class HttpClient(
                             val scanner = Scanner(inputStream, "UTF-8")
                             val json = if (scanner.useDelimiter("\\A").hasNext()) scanner.next() else ""
                             scanner.close()
-                            Logging.debug("HttpClient: ${method ?: "GET"} $url - STATUS: $httpResponse JSON: " + json)
+                            Logging.debug("HttpClient: Got Response = ${method ?: "GET"} ${con.url} - STATUS: $httpResponse - Body: " + json)
 
                             if (cacheKey != null) {
                                 val eTag = con.getHeaderField("etag")
                                 if (eTag != null) {
-                                    Logging.debug("HttpClient: Response has etag of $eTag so caching the response.")
+                                    Logging.debug("HttpClient: Got Response = Response has etag of $eTag so caching the response.")
 
                                     _prefs.saveString(
                                         PreferenceStores.ONESIGNAL,
@@ -227,7 +230,7 @@ internal class HttpClient(
                             retVal = HttpResponse(httpResponse, json, retryAfterSeconds = retryAfter)
                         }
                         else -> {
-                            Logging.debug("HttpClient: ${method ?: "GET"} $url - FAILED STATUS: $httpResponse")
+                            Logging.debug("HttpClient: Got Response = ${method ?: "GET"} ${con.url} - FAILED STATUS: $httpResponse")
 
                             var inputStream = con.errorStream
                             if (inputStream == null) {
@@ -240,9 +243,9 @@ internal class HttpClient(
                                 jsonResponse =
                                     if (scanner.useDelimiter("\\A").hasNext()) scanner.next() else ""
                                 scanner.close()
-                                Logging.warn("HttpClient: $method RECEIVED JSON: $jsonResponse")
+                                Logging.warn("HttpClient: Got Response = $method - STATUS: $httpResponse - Body: $jsonResponse")
                             } else {
-                                Logging.warn("HttpClient: $method HTTP Code: $httpResponse No response body!")
+                                Logging.warn("HttpClient: Got Response = $method - STATUS: $httpResponse - No response body!")
                             }
 
                             retVal = HttpResponse(httpResponse, jsonResponse, retryAfterSeconds = retryAfter)
@@ -285,6 +288,18 @@ internal class HttpClient(
         }
     }
 
+    private fun logHTTPSent(
+        method: String?,
+        url: URL,
+        jsonBody: JSONObject?,
+        headers: Map<String, List<String>>,
+    ) {
+        val headersStr = headers.entries.joinToString()
+        val methodStr = method ?: "GET"
+        val bodyStr = if (jsonBody != null) JSONUtils.toUnescapedEUIDString(jsonBody) else null
+        Logging.debug("HttpClient: Request Sent = $methodStr $url - Body: $bodyStr - Headers: $headersStr")
+    }
+
     companion object {
         private const val OS_API_VERSION = "1"
         private const val OS_ACCEPT_HEADER = "application/vnd.onesignal.v$OS_API_VERSION+json"
diff --git a/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/preferences/IPreferencesService.kt b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/preferences/IPreferencesService.kt
index ac0265b278..23435d8977 100644
--- a/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/preferences/IPreferencesService.kt
+++ b/OneSignalSDK/onesignal/core/src/main/java/com/onesignal/core/internal/preferences/IPreferencesService.kt
@@ -215,6 +215,13 @@ object PreferenceOneSignalKeys {
      */
     const val PREFS_OS_ETAG_PREFIX = "PREFS_OS_ETAG_PREFIX_"
 
+    /**
+     * (String) A install id, a UUIDv4 generated once when app is first opened.
+     * Value is for a HTTP header, OneSignal-Install-Id, added on all calls
+     * made to OneSignal's backend.
+     */
+    const val PREFS_OS_INSTALL_ID = "PREFS_OS_INSTALL_ID"
+
     /**
      * (String) A prefix key for retrieving the response for a given HTTP GET cache key. The cache
      * key should be appended to this prefix.
diff --git a/OneSignalSDK/onesignal/core/src/test/java/com/onesignal/core/internal/device/InstallIdServiceTests.kt b/OneSignalSDK/onesignal/core/src/test/java/com/onesignal/core/internal/device/InstallIdServiceTests.kt
new file mode 100644
index 0000000000..777d14e725
--- /dev/null
+++ b/OneSignalSDK/onesignal/core/src/test/java/com/onesignal/core/internal/device/InstallIdServiceTests.kt
@@ -0,0 +1,36 @@
+package com.onesignal.core.internal.device
+
+import com.onesignal.core.internal.device.impl.InstallIdService
+import com.onesignal.mocks.MockPreferencesService
+import io.kotest.core.spec.style.FunSpec
+import io.kotest.matchers.shouldBe
+
+class InstallIdServiceTests : FunSpec({
+    test("2 calls result in the same value") {
+        // Given
+        val service = InstallIdService(MockPreferencesService())
+
+        // When
+        val value1 = service.getId()
+        val value2 = service.getId()
+
+        // Then
+        value1 shouldBe value2
+    }
+
+    // Real world scenario we are testing is if we cold restart the app we get
+    // the same value
+    test("reads from shared prefs") {
+        // Given
+        val sharedPrefs = MockPreferencesService()
+
+        // When
+        val service1 = InstallIdService(sharedPrefs)
+        val value1 = service1.getId()
+        val service2 = InstallIdService(sharedPrefs)
+        val value2 = service2.getId()
+
+        // Then
+        value1 shouldBe value2
+    }
+})
diff --git a/OneSignalSDK/onesignal/core/src/test/java/com/onesignal/core/internal/http/HttpClientTests.kt b/OneSignalSDK/onesignal/core/src/test/java/com/onesignal/core/internal/http/HttpClientTests.kt
index 07ce545f61..a14039559a 100644
--- a/OneSignalSDK/onesignal/core/src/test/java/com/onesignal/core/internal/http/HttpClientTests.kt
+++ b/OneSignalSDK/onesignal/core/src/test/java/com/onesignal/core/internal/http/HttpClientTests.kt
@@ -1,6 +1,7 @@
 package com.onesignal.core.internal.http
 
 import com.onesignal.common.OneSignalUtils
+import com.onesignal.core.internal.device.impl.InstallIdService
 import com.onesignal.core.internal.http.impl.HttpClient
 import com.onesignal.core.internal.time.impl.Time
 import com.onesignal.debug.LogLevel
@@ -20,8 +21,9 @@ class Mocks {
     internal val mockConfigModel = MockHelper.configModelStore()
     internal val response = MockHttpConnectionFactory.MockResponse()
     internal val factory = MockHttpConnectionFactory(response)
+    internal val installIdService = InstallIdService(MockPreferencesService())
     internal val httpClient by lazy {
-        HttpClient(factory, MockPreferencesService(), mockConfigModel, Time())
+        HttpClient(factory, MockPreferencesService(), mockConfigModel, Time(), installIdService)
     }
 }
 
@@ -50,7 +52,7 @@ class HttpClientTests : FunSpec({
         response.throwable should beInstanceOf<TimeoutCancellationException>()
     }
 
-    test("SDKHeader is included in all requests") {
+    test("SDK Headers are included in all requests") {
         // Given
         val mocks = Mocks()
         val httpClient = mocks.httpClient
@@ -65,6 +67,7 @@ class HttpClientTests : FunSpec({
         // Then
         for (connection in mocks.factory.connections) {
             connection.getRequestProperty("SDK-Version") shouldBe "onesignal/android/${OneSignalUtils.SDK_VERSION}"
+            connection.getRequestProperty("OneSignal-Install-Id") shouldBe mocks.installIdService.getId().toString()
         }
     }