diff --git a/MembraneRTC/src/main/java/org/membraneframework/rtc/InternalMembraneRTC.kt b/MembraneRTC/src/main/java/org/membraneframework/rtc/InternalMembraneRTC.kt
index a45f13c..b2f2a8d 100644
--- a/MembraneRTC/src/main/java/org/membraneframework/rtc/InternalMembraneRTC.kt
+++ b/MembraneRTC/src/main/java/org/membraneframework/rtc/InternalMembraneRTC.kt
@@ -248,7 +248,8 @@ internal class InternalMembraneRTC
                 this.remoteEndpoints[it.id] = it
 
                 for ((trackId, metadata) in it.trackIdToMetadata) {
-                    val context = TrackContext(track = null, endpoint = it, trackId = trackId, metadata = metadata)
+                    val context =
+                        TrackContext(track = null, endpoint = it, trackId = trackId, metadata = metadata ?: mapOf())
 
                     this.trackContexts[trackId] = context
 
@@ -295,7 +296,7 @@ internal class InternalMembraneRTC
 
         override fun onEndpointUpdated(
             endpointId: String,
-            endpointMetadata: Metadata
+            endpointMetadata: Metadata?
         ) {
             val endpoint =
                 remoteEndpoints.remove(endpointId) ?: run {
@@ -374,7 +375,7 @@ internal class InternalMembraneRTC
 
         override fun onTracksAdded(
             endpointId: String,
-            trackIdToMetadata: Map<String, Metadata>
+            trackIdToMetadata: Map<String, Metadata?>
         ) {
             if (localEndpoint.id == endpointId) return
 
@@ -389,7 +390,8 @@ internal class InternalMembraneRTC
             remoteEndpoints[updatedEndpoint.id] = updatedEndpoint
 
             for ((trackId, metadata) in updatedEndpoint.trackIdToMetadata) {
-                val context = TrackContext(track = null, endpoint = endpoint, trackId = trackId, metadata = metadata)
+                val context =
+                    TrackContext(track = null, endpoint = endpoint, trackId = trackId, metadata = metadata ?: mapOf())
 
                 this.trackContexts[trackId] = context
 
@@ -424,7 +426,7 @@ internal class InternalMembraneRTC
         override fun onTrackUpdated(
             endpointId: String,
             trackId: String,
-            metadata: Metadata
+            metadata: Metadata?
         ) {
             val endpoint =
                 remoteEndpoints[endpointId] ?: run {
@@ -438,7 +440,7 @@ internal class InternalMembraneRTC
                     return
                 }
 
-            context.metadata = metadata
+            context.metadata = metadata ?: mapOf()
 
             val updatedEndpoint =
                 endpoint
diff --git a/MembraneRTC/src/main/java/org/membraneframework/rtc/RTCEngineCommunication.kt b/MembraneRTC/src/main/java/org/membraneframework/rtc/RTCEngineCommunication.kt
index fefa00b..9bb50d2 100644
--- a/MembraneRTC/src/main/java/org/membraneframework/rtc/RTCEngineCommunication.kt
+++ b/MembraneRTC/src/main/java/org/membraneframework/rtc/RTCEngineCommunication.kt
@@ -67,7 +67,7 @@ internal class RTCEngineCommunication
 
         fun sdpOffer(
             sdp: String,
-            trackIdToTrackMetadata: Map<String, Metadata>,
+            trackIdToTrackMetadata: Map<String, Metadata?>,
             midToTrackId: Map<String, String>
         ) {
             sendEvent(
diff --git a/MembraneRTC/src/main/java/org/membraneframework/rtc/RTCEngineListener.kt b/MembraneRTC/src/main/java/org/membraneframework/rtc/RTCEngineListener.kt
index aa01293..dd446e9 100644
--- a/MembraneRTC/src/main/java/org/membraneframework/rtc/RTCEngineListener.kt
+++ b/MembraneRTC/src/main/java/org/membraneframework/rtc/RTCEngineListener.kt
@@ -19,7 +19,7 @@ internal interface RTCEngineListener {
 
     fun onEndpointUpdated(
         endpointId: String,
-        endpointMetadata: Metadata
+        endpointMetadata: Metadata? = mapOf()
     )
 
     fun onOfferData(
@@ -41,7 +41,7 @@ internal interface RTCEngineListener {
 
     fun onTracksAdded(
         endpointId: String,
-        trackIdToMetadata: Map<String, Metadata>
+        trackIdToMetadata: Map<String, Metadata?>
     )
 
     fun onTracksRemoved(
@@ -52,7 +52,7 @@ internal interface RTCEngineListener {
     fun onTrackUpdated(
         endpointId: String,
         trackId: String,
-        metadata: Metadata
+        metadata: Metadata? = mapOf()
     )
 
     fun onTrackEncodingChanged(
diff --git a/MembraneRTC/src/main/java/org/membraneframework/rtc/events/Event.kt b/MembraneRTC/src/main/java/org/membraneframework/rtc/events/Event.kt
index cc8a974..d0d4761 100644
--- a/MembraneRTC/src/main/java/org/membraneframework/rtc/events/Event.kt
+++ b/MembraneRTC/src/main/java/org/membraneframework/rtc/events/Event.kt
@@ -30,13 +30,13 @@ internal inline fun <I, reified O> I.convert(): O {
 sealed class SendableEvent
 
 data class Connect(val type: String, val data: Data) : SendableEvent() {
-    data class Data(val metadata: Metadata)
+    data class Data(val metadata: Metadata?)
 
-    constructor(metadata: Metadata) : this("connect", Data(metadata))
+    constructor(metadata: Metadata? = mapOf()) : this("connect", Data(metadata))
 }
 
 data class SdpOffer(val type: String, val data: Payload) : SendableEvent() {
-    constructor(sdp: String, trackIdToTrackMetadata: Map<String, Metadata>, midToTrackId: Map<String, String>) :
+    constructor(sdp: String, trackIdToTrackMetadata: Map<String, Metadata?>, midToTrackId: Map<String, String>) :
         this(
             "custom",
             mapOf(
@@ -96,15 +96,18 @@ data class SelectEncoding(val type: String, val data: Payload) : SendableEvent()
 }
 
 data class UpdateEndpointMetadata(val type: String, val data: Data) : SendableEvent() {
-    data class Data(val metadata: Metadata)
+    data class Data(val metadata: Metadata?)
 
-    constructor(metadata: Metadata) : this("updateEndpointMetadata", Data(metadata))
+    constructor(metadata: Metadata? = mapOf()) : this("updateEndpointMetadata", Data(metadata))
 }
 
 data class UpdateTrackMetadata(val type: String, val data: Data) : SendableEvent() {
-    data class Data(val trackId: String, val trackMetadata: Metadata)
+    data class Data(val trackId: String, val trackMetadata: Metadata?)
 
-    constructor(trackId: String, trackMetadata: Metadata) : this("updateTrackMetadata", Data(trackId, trackMetadata))
+    constructor(trackId: String, trackMetadata: Metadata = mapOf()) : this(
+        "updateTrackMetadata",
+        Data(trackId, trackMetadata)
+    )
 }
 
 data class Disconnect(val type: String) : SendableEvent() {
@@ -231,13 +234,13 @@ data class EndpointAdded(val type: ReceivableEventType, val data: Data) : Receiv
     data class Data(
         val id: String,
         val type: String,
-        val metadata: Metadata,
-        val trackIdToMetadata: Map<String, Metadata>
+        val metadata: Metadata?,
+        val trackIdToMetadata: Map<String, Metadata?>
     )
 }
 
 data class EndpointUpdated(val type: ReceivableEventType, val data: Data) : ReceivableEvent() {
-    data class Data(val id: String, val metadata: Metadata)
+    data class Data(val id: String, val metadata: Metadata?)
 }
 
 data class EndpointRemoved(val type: ReceivableEventType, val data: Data) : ReceivableEvent() {
@@ -257,7 +260,7 @@ data class OfferData(val type: ReceivableEventType, val data: Data) : Receivable
 }
 
 data class TracksAdded(val type: ReceivableEventType, val data: Data) : ReceivableEvent() {
-    data class Data(val endpointId: String, val trackIdToMetadata: Map<String, Metadata>)
+    data class Data(val endpointId: String, val trackIdToMetadata: Map<String, Metadata?>)
 }
 
 data class TracksRemoved(val type: ReceivableEventType, val data: Data) : ReceivableEvent() {
@@ -265,7 +268,7 @@ data class TracksRemoved(val type: ReceivableEventType, val data: Data) : Receiv
 }
 
 data class TrackUpdated(val type: ReceivableEventType, val data: Data) : ReceivableEvent() {
-    data class Data(val endpointId: String, val trackId: String, val metadata: Metadata)
+    data class Data(val endpointId: String, val trackId: String, val metadata: Metadata?)
 }
 
 data class SdpAnswer(val type: ReceivableEventType, val data: Data) : ReceivableEvent() {
diff --git a/MembraneRTC/src/main/java/org/membraneframework/rtc/models/Endpoint.kt b/MembraneRTC/src/main/java/org/membraneframework/rtc/models/Endpoint.kt
index 3797ca8..0aa2aa2 100644
--- a/MembraneRTC/src/main/java/org/membraneframework/rtc/models/Endpoint.kt
+++ b/MembraneRTC/src/main/java/org/membraneframework/rtc/models/Endpoint.kt
@@ -6,7 +6,7 @@ data class Endpoint(
     val id: String,
     val type: String,
     val metadata: Metadata? = mapOf(),
-    val trackIdToMetadata: Map<String, Metadata> = mapOf()
+    val trackIdToMetadata: Map<String, Metadata?> = mapOf()
 ) {
     fun withTrack(
         trackId: String,
diff --git a/MembraneRTC/src/main/java/org/membraneframework/rtc/models/TrackContext.kt b/MembraneRTC/src/main/java/org/membraneframework/rtc/models/TrackContext.kt
index 430c3c0..3ced8e4 100644
--- a/MembraneRTC/src/main/java/org/membraneframework/rtc/models/TrackContext.kt
+++ b/MembraneRTC/src/main/java/org/membraneframework/rtc/models/TrackContext.kt
@@ -19,7 +19,7 @@ fun interface OnVoiceActivityChangedListener {
  * @property trackId Track id. It is generated by RTC engine and takes form `endpoint_id:<random_uuidv4>`.
  * @property metadata Any info that was passed in MembraneWebRTC.createVideoTrack/MembraneWebRTC.createAudioTrack
  */
-class TrackContext(track: RemoteTrack?, val endpoint: Endpoint, val trackId: String, metadata: Metadata) {
+class TrackContext(track: RemoteTrack?, val endpoint: Endpoint, val trackId: String, metadata: Metadata = mapOf()) {
     private var onTrackEncodingChangeListener: (OnEncodingChangedListener)? = null
     private var onVadNotificationListener: (OnVoiceActivityChangedListener)? = null