diff --git a/embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/injection/SessionModule.kt b/embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/injection/SessionModule.kt
index 87288c99b..83f7fcf77 100644
--- a/embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/injection/SessionModule.kt
+++ b/embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/injection/SessionModule.kt
@@ -7,6 +7,7 @@ import io.embrace.android.embracesdk.session.caching.PeriodicSessionCacher
 import io.embrace.android.embracesdk.session.message.PayloadFactory
 import io.embrace.android.embracesdk.session.message.PayloadFactoryImpl
 import io.embrace.android.embracesdk.session.message.PayloadMessageCollator
+import io.embrace.android.embracesdk.session.message.PayloadMessageCollatorImpl
 import io.embrace.android.embracesdk.session.orchestrator.OrchestratorBoundaryDelegate
 import io.embrace.android.embracesdk.session.orchestrator.SessionOrchestrator
 import io.embrace.android.embracesdk.session.orchestrator.SessionOrchestratorImpl
@@ -43,7 +44,7 @@ internal class SessionModuleImpl(
 ) : SessionModule {
 
     override val payloadMessageCollator: PayloadMessageCollator by singleton {
-        PayloadMessageCollator(
+        PayloadMessageCollatorImpl(
             essentialServiceModule.configService,
             essentialServiceModule.metadataService,
             dataContainerModule.eventService,
diff --git a/embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/session/message/PayloadMessageCollator.kt b/embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/session/message/PayloadMessageCollator.kt
index c9fd5ecfe..41608b553 100644
--- a/embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/session/message/PayloadMessageCollator.kt
+++ b/embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/session/message/PayloadMessageCollator.kt
@@ -1,193 +1,26 @@
 package io.embrace.android.embracesdk.session.message
 
-import io.embrace.android.embracesdk.anr.ndk.NativeThreadSamplerService
-import io.embrace.android.embracesdk.arch.schema.AppTerminationCause
-import io.embrace.android.embracesdk.capture.PerformanceInfoService
-import io.embrace.android.embracesdk.capture.crumbs.BreadcrumbService
-import io.embrace.android.embracesdk.capture.metadata.MetadataService
-import io.embrace.android.embracesdk.capture.startup.StartupService
-import io.embrace.android.embracesdk.capture.thermalstate.ThermalStatusService
-import io.embrace.android.embracesdk.capture.user.UserService
-import io.embrace.android.embracesdk.capture.webview.WebViewService
-import io.embrace.android.embracesdk.config.ConfigService
-import io.embrace.android.embracesdk.event.EventService
-import io.embrace.android.embracesdk.event.LogMessageService
-import io.embrace.android.embracesdk.internal.spans.CurrentSessionSpan
-import io.embrace.android.embracesdk.internal.spans.EmbraceSpanData
-import io.embrace.android.embracesdk.internal.spans.SpanSink
-import io.embrace.android.embracesdk.internal.utils.Uuid
-import io.embrace.android.embracesdk.logging.InternalErrorService
-import io.embrace.android.embracesdk.payload.BetaFeatures
 import io.embrace.android.embracesdk.payload.Session
 import io.embrace.android.embracesdk.payload.SessionMessage
-import io.embrace.android.embracesdk.prefs.PreferencesService
-import io.embrace.android.embracesdk.session.captureDataSafely
-import io.embrace.android.embracesdk.session.properties.SessionPropertiesService
+import io.embrace.android.embracesdk.session.message.FinalEnvelopeParams.BackgroundActivityParams
+import io.embrace.android.embracesdk.session.message.FinalEnvelopeParams.SessionParams
 
-internal class PayloadMessageCollator(
-    private val configService: ConfigService,
-    private val metadataService: MetadataService,
-    private val eventService: EventService,
-    private val logMessageService: LogMessageService,
-    private val internalErrorService: InternalErrorService,
-    private val performanceInfoService: PerformanceInfoService,
-    private val webViewService: WebViewService,
-    private val thermalStatusService: ThermalStatusService,
-    private val nativeThreadSamplerService: NativeThreadSamplerService?,
-    private val breadcrumbService: BreadcrumbService,
-    private val userService: UserService,
-    private val preferencesService: PreferencesService,
-    private val spanSink: SpanSink,
-    private val currentSessionSpan: CurrentSessionSpan,
-    private val sessionPropertiesService: SessionPropertiesService,
-    private val startupService: StartupService
-) {
+internal interface PayloadMessageCollator {
 
     /**
      * Builds a new session object. This should not be sent to the backend but is used
      * to populate essential session information (such as ID), etc
      */
-    internal fun buildInitialSession(params: InitialEnvelopeParams) = with(params) {
-        Session(
-            sessionId = Uuid.getEmbUuid(),
-            startTime = startTime,
-            isColdStart = coldStart,
-            messageType = Session.MESSAGE_TYPE_END,
-            appState = appState,
-            startType = startType,
-            number = getSessionNumber(preferencesService),
-            properties = getProperties(sessionPropertiesService),
-        )
-    }
+    fun buildInitialSession(params: InitialEnvelopeParams): Session
 
     /**
      * Builds a fully populated session message. This can be sent to the backend (or stored
      * on disk).
      */
-    internal fun buildFinalSessionMessage(
-        params: FinalEnvelopeParams.SessionParams
-    ): SessionMessage = with(params) {
-        val base = buildFinalBackgroundActivity(params)
-        val startupInfo = getStartupEventInfo(eventService)
-
-        val betaFeatures = when (configService.sdkModeBehavior.isBetaFeaturesEnabled()) {
-            false -> null
-            else -> BetaFeatures(
-                thermalStates = captureDataSafely(thermalStatusService::getCapturedData),
-            )
-        }
-
-        val endSession = base.copy(
-            isEndedCleanly = endType.endedCleanly,
-            networkLogIds = captureDataSafely {
-                logMessageService.findNetworkLogIds(
-                    initial.startTime,
-                    endTime
-                )
-            },
-            properties = captureDataSafely(sessionPropertiesService::getProperties),
-            webViewInfo = captureDataSafely(webViewService::getCapturedData),
-            terminationTime = terminationTime,
-            isReceivedTermination = receivedTermination,
-            endTime = endTimeVal,
-            sdkStartupDuration = startupService.getSdkStartupDuration(initial.isColdStart),
-            startupDuration = startupInfo?.duration,
-            startupThreshold = startupInfo?.threshold,
-            betaFeatures = betaFeatures,
-            symbols = captureDataSafely { nativeThreadSamplerService?.getNativeSymbols() }
-        )
-        return buildWrapperEnvelope(params, endSession, initial.startTime, endTime)
-    }
+    fun buildFinalSessionMessage(params: SessionParams): SessionMessage
 
     /**
      * Create the background session message with the current state of the background activity.
      */
-    fun buildFinalBackgroundActivityMessage(
-        params: FinalEnvelopeParams.BackgroundActivityParams
-    ): SessionMessage {
-        val msg = buildFinalBackgroundActivity(params)
-        val startTime = msg.startTime
-        val endTime = params.endTime
-        return buildWrapperEnvelope(params, msg, startTime, endTime)
-    }
-
-    /**
-     * Creates a background activity stop message.
-     */
-    private fun buildFinalBackgroundActivity(
-        params: FinalEnvelopeParams
-    ): Session = with(params) {
-        val startTime = initial.startTime
-        return initial.copy(
-            endTime = endTime,
-            eventIds = captureDataSafely {
-                eventService.findEventIdsForSession()
-            },
-            infoLogIds = captureDataSafely { logMessageService.findInfoLogIds(startTime, endTime) },
-            warningLogIds = captureDataSafely {
-                logMessageService.findWarningLogIds(
-                    startTime,
-                    endTime
-                )
-            },
-            errorLogIds = captureDataSafely {
-                logMessageService.findErrorLogIds(
-                    startTime,
-                    endTime
-                )
-            },
-            infoLogsAttemptedToSend = captureDataSafely(logMessageService::getInfoLogsAttemptedToSend),
-            warnLogsAttemptedToSend = captureDataSafely(logMessageService::getWarnLogsAttemptedToSend),
-            errorLogsAttemptedToSend = captureDataSafely(logMessageService::getErrorLogsAttemptedToSend),
-            exceptionError = captureDataSafely(internalErrorService::currentExceptionError),
-            lastHeartbeatTime = endTime,
-            endType = lifeEventType,
-            unhandledExceptions = captureDataSafely(logMessageService::getUnhandledExceptionsSent),
-            crashReportId = crashId
-        )
-    }
-
-    private fun buildWrapperEnvelope(
-        params: FinalEnvelopeParams,
-        finalPayload: Session,
-        startTime: Long,
-        endTime: Long
-    ): SessionMessage {
-        val spans: List<EmbraceSpanData>? = captureDataSafely {
-            when {
-                !params.isCacheAttempt -> {
-                    val appTerminationCause = when {
-                        finalPayload.crashReportId != null -> AppTerminationCause.Crash
-                        else -> null
-                    }
-                    currentSessionSpan.endSession(appTerminationCause)
-                }
-
-                else -> spanSink.completedSpans()
-            }
-        }
-        val breadcrumbs = captureDataSafely {
-            when {
-                !params.isCacheAttempt -> breadcrumbService.flushBreadcrumbs()
-                else -> breadcrumbService.getBreadcrumbs()
-            }
-        }
-
-        return SessionMessage(
-            session = finalPayload,
-            userInfo = captureDataSafely(userService::getUserInfo),
-            appInfo = captureDataSafely(metadataService::getAppInfo),
-            deviceInfo = captureDataSafely(metadataService::getDeviceInfo),
-            performanceInfo = captureDataSafely {
-                performanceInfoService.getSessionPerformanceInfo(
-                    startTime,
-                    endTime,
-                    finalPayload.isColdStart,
-                    null
-                )
-            },
-            breadcrumbs = breadcrumbs,
-            spans = spans
-        )
-    }
+    fun buildFinalBackgroundActivityMessage(params: BackgroundActivityParams): SessionMessage
 }
diff --git a/embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/session/message/PayloadMessageCollatorImpl.kt b/embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/session/message/PayloadMessageCollatorImpl.kt
new file mode 100644
index 000000000..21ff2f68b
--- /dev/null
+++ b/embrace-android-sdk/src/main/java/io/embrace/android/embracesdk/session/message/PayloadMessageCollatorImpl.kt
@@ -0,0 +1,193 @@
+package io.embrace.android.embracesdk.session.message
+
+import io.embrace.android.embracesdk.anr.ndk.NativeThreadSamplerService
+import io.embrace.android.embracesdk.arch.schema.AppTerminationCause
+import io.embrace.android.embracesdk.capture.PerformanceInfoService
+import io.embrace.android.embracesdk.capture.crumbs.BreadcrumbService
+import io.embrace.android.embracesdk.capture.metadata.MetadataService
+import io.embrace.android.embracesdk.capture.startup.StartupService
+import io.embrace.android.embracesdk.capture.thermalstate.ThermalStatusService
+import io.embrace.android.embracesdk.capture.user.UserService
+import io.embrace.android.embracesdk.capture.webview.WebViewService
+import io.embrace.android.embracesdk.config.ConfigService
+import io.embrace.android.embracesdk.event.EventService
+import io.embrace.android.embracesdk.event.LogMessageService
+import io.embrace.android.embracesdk.internal.spans.CurrentSessionSpan
+import io.embrace.android.embracesdk.internal.spans.EmbraceSpanData
+import io.embrace.android.embracesdk.internal.spans.SpanSink
+import io.embrace.android.embracesdk.internal.utils.Uuid
+import io.embrace.android.embracesdk.logging.InternalErrorService
+import io.embrace.android.embracesdk.payload.BetaFeatures
+import io.embrace.android.embracesdk.payload.Session
+import io.embrace.android.embracesdk.payload.SessionMessage
+import io.embrace.android.embracesdk.prefs.PreferencesService
+import io.embrace.android.embracesdk.session.captureDataSafely
+import io.embrace.android.embracesdk.session.properties.SessionPropertiesService
+
+internal class PayloadMessageCollatorImpl(
+    private val configService: ConfigService,
+    private val metadataService: MetadataService,
+    private val eventService: EventService,
+    private val logMessageService: LogMessageService,
+    private val internalErrorService: InternalErrorService,
+    private val performanceInfoService: PerformanceInfoService,
+    private val webViewService: WebViewService,
+    private val thermalStatusService: ThermalStatusService,
+    private val nativeThreadSamplerService: NativeThreadSamplerService?,
+    private val breadcrumbService: BreadcrumbService,
+    private val userService: UserService,
+    private val preferencesService: PreferencesService,
+    private val spanSink: SpanSink,
+    private val currentSessionSpan: CurrentSessionSpan,
+    private val sessionPropertiesService: SessionPropertiesService,
+    private val startupService: StartupService
+) : PayloadMessageCollator {
+
+    /**
+     * Builds a new session object. This should not be sent to the backend but is used
+     * to populate essential session information (such as ID), etc
+     */
+    override fun buildInitialSession(params: InitialEnvelopeParams) = with(params) {
+        Session(
+            sessionId = Uuid.getEmbUuid(),
+            startTime = startTime,
+            isColdStart = coldStart,
+            messageType = Session.MESSAGE_TYPE_END,
+            appState = appState,
+            startType = startType,
+            number = getSessionNumber(preferencesService),
+            properties = getProperties(sessionPropertiesService),
+        )
+    }
+
+    /**
+     * Builds a fully populated session message. This can be sent to the backend (or stored
+     * on disk).
+     */
+    override fun buildFinalSessionMessage(
+        params: FinalEnvelopeParams.SessionParams
+    ): SessionMessage = with(params) {
+        val base = buildFinalBackgroundActivity(params)
+        val startupInfo = getStartupEventInfo(eventService)
+
+        val betaFeatures = when (configService.sdkModeBehavior.isBetaFeaturesEnabled()) {
+            false -> null
+            else -> BetaFeatures(
+                thermalStates = captureDataSafely(thermalStatusService::getCapturedData),
+            )
+        }
+
+        val endSession = base.copy(
+            isEndedCleanly = endType.endedCleanly,
+            networkLogIds = captureDataSafely {
+                logMessageService.findNetworkLogIds(
+                    initial.startTime,
+                    endTime
+                )
+            },
+            properties = captureDataSafely(sessionPropertiesService::getProperties),
+            webViewInfo = captureDataSafely(webViewService::getCapturedData),
+            terminationTime = terminationTime,
+            isReceivedTermination = receivedTermination,
+            endTime = endTimeVal,
+            sdkStartupDuration = startupService.getSdkStartupDuration(initial.isColdStart),
+            startupDuration = startupInfo?.duration,
+            startupThreshold = startupInfo?.threshold,
+            betaFeatures = betaFeatures,
+            symbols = captureDataSafely { nativeThreadSamplerService?.getNativeSymbols() }
+        )
+        return buildWrapperEnvelope(params, endSession, initial.startTime, endTime)
+    }
+
+    /**
+     * Create the background session message with the current state of the background activity.
+     */
+    override fun buildFinalBackgroundActivityMessage(
+        params: FinalEnvelopeParams.BackgroundActivityParams
+    ): SessionMessage {
+        val msg = buildFinalBackgroundActivity(params)
+        val startTime = msg.startTime
+        val endTime = params.endTime
+        return buildWrapperEnvelope(params, msg, startTime, endTime)
+    }
+
+    /**
+     * Creates a background activity stop message.
+     */
+    private fun buildFinalBackgroundActivity(
+        params: FinalEnvelopeParams
+    ): Session = with(params) {
+        val startTime = initial.startTime
+        return initial.copy(
+            endTime = endTime,
+            eventIds = captureDataSafely {
+                eventService.findEventIdsForSession()
+            },
+            infoLogIds = captureDataSafely { logMessageService.findInfoLogIds(startTime, endTime) },
+            warningLogIds = captureDataSafely {
+                logMessageService.findWarningLogIds(
+                    startTime,
+                    endTime
+                )
+            },
+            errorLogIds = captureDataSafely {
+                logMessageService.findErrorLogIds(
+                    startTime,
+                    endTime
+                )
+            },
+            infoLogsAttemptedToSend = captureDataSafely(logMessageService::getInfoLogsAttemptedToSend),
+            warnLogsAttemptedToSend = captureDataSafely(logMessageService::getWarnLogsAttemptedToSend),
+            errorLogsAttemptedToSend = captureDataSafely(logMessageService::getErrorLogsAttemptedToSend),
+            exceptionError = captureDataSafely(internalErrorService::currentExceptionError),
+            lastHeartbeatTime = endTime,
+            endType = lifeEventType,
+            unhandledExceptions = captureDataSafely(logMessageService::getUnhandledExceptionsSent),
+            crashReportId = crashId
+        )
+    }
+
+    private fun buildWrapperEnvelope(
+        params: FinalEnvelopeParams,
+        finalPayload: Session,
+        startTime: Long,
+        endTime: Long
+    ): SessionMessage {
+        val spans: List<EmbraceSpanData>? = captureDataSafely {
+            when {
+                !params.isCacheAttempt -> {
+                    val appTerminationCause = when {
+                        finalPayload.crashReportId != null -> AppTerminationCause.Crash
+                        else -> null
+                    }
+                    currentSessionSpan.endSession(appTerminationCause)
+                }
+
+                else -> spanSink.completedSpans()
+            }
+        }
+        val breadcrumbs = captureDataSafely {
+            when {
+                !params.isCacheAttempt -> breadcrumbService.flushBreadcrumbs()
+                else -> breadcrumbService.getBreadcrumbs()
+            }
+        }
+
+        return SessionMessage(
+            session = finalPayload,
+            userInfo = captureDataSafely(userService::getUserInfo),
+            appInfo = captureDataSafely(metadataService::getAppInfo),
+            deviceInfo = captureDataSafely(metadataService::getDeviceInfo),
+            performanceInfo = captureDataSafely {
+                performanceInfoService.getSessionPerformanceInfo(
+                    startTime,
+                    endTime,
+                    finalPayload.isColdStart,
+                    null
+                )
+            },
+            breadcrumbs = breadcrumbs,
+            spans = spans
+        )
+    }
+}
diff --git a/embrace-android-sdk/src/test/java/io/embrace/android/embracesdk/session/PayloadFactoryBaTest.kt b/embrace-android-sdk/src/test/java/io/embrace/android/embracesdk/session/PayloadFactoryBaTest.kt
index c59d77b32..2d460fec4 100644
--- a/embrace-android-sdk/src/test/java/io/embrace/android/embracesdk/session/PayloadFactoryBaTest.kt
+++ b/embrace-android-sdk/src/test/java/io/embrace/android/embracesdk/session/PayloadFactoryBaTest.kt
@@ -34,7 +34,7 @@ import io.embrace.android.embracesdk.internal.spans.SpanSink
 import io.embrace.android.embracesdk.logging.InternalErrorService
 import io.embrace.android.embracesdk.session.lifecycle.ProcessState
 import io.embrace.android.embracesdk.session.message.PayloadFactoryImpl
-import io.embrace.android.embracesdk.session.message.PayloadMessageCollator
+import io.embrace.android.embracesdk.session.message.PayloadMessageCollatorImpl
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertTrue
 import org.junit.Before
@@ -153,7 +153,7 @@ internal class PayloadFactoryBaTest {
     }
 
     private fun createService(createInitialSession: Boolean = true): PayloadFactoryImpl {
-        val collator = PayloadMessageCollator(
+        val collator = PayloadMessageCollatorImpl(
             configService,
             metadataService,
             eventService,
diff --git a/embrace-android-sdk/src/test/java/io/embrace/android/embracesdk/session/PayloadMessageCollatorTest.kt b/embrace-android-sdk/src/test/java/io/embrace/android/embracesdk/session/PayloadMessageCollatorTest.kt
index ff7c41440..c908f8a70 100644
--- a/embrace-android-sdk/src/test/java/io/embrace/android/embracesdk/session/PayloadMessageCollatorTest.kt
+++ b/embrace-android-sdk/src/test/java/io/embrace/android/embracesdk/session/PayloadMessageCollatorTest.kt
@@ -21,6 +21,7 @@ import io.embrace.android.embracesdk.payload.SessionMessage
 import io.embrace.android.embracesdk.session.message.FinalEnvelopeParams
 import io.embrace.android.embracesdk.session.message.InitialEnvelopeParams
 import io.embrace.android.embracesdk.session.message.PayloadMessageCollator
+import io.embrace.android.embracesdk.session.message.PayloadMessageCollatorImpl
 import io.embrace.android.embracesdk.session.orchestrator.SessionSnapshotType
 import org.junit.Assert.assertEquals
 import org.junit.Assert.assertFalse
@@ -41,7 +42,7 @@ internal class PayloadMessageCollatorTest {
     @Before
     fun setUp() {
         initModule = FakeInitModule()
-        collator = PayloadMessageCollator(
+        collator = PayloadMessageCollatorImpl(
             configService = FakeConfigService(),
             nativeThreadSamplerService = null,
             thermalStatusService = FakeThermalStatusService(),
diff --git a/embrace-android-sdk/src/test/java/io/embrace/android/embracesdk/session/SessionHandlerTest.kt b/embrace-android-sdk/src/test/java/io/embrace/android/embracesdk/session/SessionHandlerTest.kt
index 31b593484..0d2a0c541 100644
--- a/embrace-android-sdk/src/test/java/io/embrace/android/embracesdk/session/SessionHandlerTest.kt
+++ b/embrace-android-sdk/src/test/java/io/embrace/android/embracesdk/session/SessionHandlerTest.kt
@@ -42,7 +42,7 @@ import io.embrace.android.embracesdk.payload.SessionMessage
 import io.embrace.android.embracesdk.session.lifecycle.ProcessState
 import io.embrace.android.embracesdk.session.message.PayloadFactory
 import io.embrace.android.embracesdk.session.message.PayloadFactoryImpl
-import io.embrace.android.embracesdk.session.message.PayloadMessageCollator
+import io.embrace.android.embracesdk.session.message.PayloadMessageCollatorImpl
 import io.embrace.android.embracesdk.session.properties.EmbraceSessionProperties
 import io.embrace.android.embracesdk.worker.ScheduledWorker
 import io.mockk.clearAllMocks
@@ -135,7 +135,7 @@ internal class SessionHandlerTest {
         val initModule = FakeInitModule(clock = clock)
         spanSink = initModule.openTelemetryModule.spanSink
         spanService = initModule.openTelemetryModule.spanService
-        val payloadMessageCollator = PayloadMessageCollator(
+        val payloadMessageCollator = PayloadMessageCollatorImpl(
             configService,
             metadataService,
             eventService,