diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/EventContextResponse.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/EventContextResponse.kt
index bce03354d7..654cf0fb74 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/EventContextResponse.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/EventContextResponse.kt
@@ -21,16 +21,34 @@ import com.squareup.moshi.JsonClass
 import org.matrix.android.sdk.api.session.events.model.Event
 
 @JsonClass(generateAdapter = true)
-data class EventContextResponse(
+internal data class EventContextResponse(
+        /**
+         * Details of the requested event.
+         */
         @Json(name = "event") val event: Event,
+        /**
+         * A token that can be used to paginate backwards with.
+         */
         @Json(name = "start") override val start: String? = null,
-        @Json(name = "events_before") val eventsBefore: List<Event> = emptyList(),
-        @Json(name = "events_after") val eventsAfter: List<Event> = emptyList(),
+        /**
+         * A list of room events that happened just before the requested event, in reverse-chronological order.
+         */
+        @Json(name = "events_before") val eventsBefore: List<Event>? = null,
+        /**
+         * A list of room events that happened just after the requested event, in chronological order.
+         */
+        @Json(name = "events_after") val eventsAfter: List<Event>? = null,
+        /**
+         * A token that can be used to paginate forwards with.
+         */
         @Json(name = "end") override val end: String? = null,
-        @Json(name = "state") override val stateEvents: List<Event> = emptyList()
+        /**
+         * The state of the room at the last event returned.
+         */
+        @Json(name = "state") override val stateEvents: List<Event>? = null
 ) : TokenChunkEvent {
 
     override val events: List<Event> by lazy {
-        eventsAfter.reversed() + listOf(event) + eventsBefore
+        eventsAfter.orEmpty().reversed() + event + eventsBefore.orEmpty()
     }
 }
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/PaginationResponse.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/PaginationResponse.kt
index ed384d3b3c..2f61b1cce8 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/PaginationResponse.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/PaginationResponse.kt
@@ -22,8 +22,28 @@ import org.matrix.android.sdk.api.session.events.model.Event
 
 @JsonClass(generateAdapter = true)
 internal data class PaginationResponse(
+        /**
+         * The token the pagination starts from. If dir=b this will be the token supplied in from.
+         */
         @Json(name = "start") override val start: String? = null,
+        /**
+         * The token the pagination ends at. If dir=b this token should be used again to request even earlier events.
+         */
         @Json(name = "end") override val end: String? = null,
-        @Json(name = "chunk") override val events: List<Event> = emptyList(),
-        @Json(name = "state") override val stateEvents: List<Event> = emptyList()
-) : TokenChunkEvent
+        /**
+         * A list of room events. The order depends on the dir parameter. For dir=b events will be in
+         * reverse-chronological order, for dir=f in chronological order, so that events start at the from point.
+         */
+        @Json(name = "chunk") val chunk: List<Event>? = null,
+        /**
+         * A list of state events relevant to showing the chunk. For example, if lazy_load_members is enabled
+         * in the filter then this may contain the membership events for the senders of events in the chunk.
+         *
+         * Unless include_redundant_members is true, the server may remove membership events which would have
+         * already been sent to the client in prior calls to this endpoint, assuming the membership of those members has not changed.
+         */
+        @Json(name = "state") override val stateEvents: List<Event>? = null
+) : TokenChunkEvent {
+    override val events: List<Event>
+        get() = chunk.orEmpty()
+}
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/TokenChunkEvent.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/TokenChunkEvent.kt
index 08b20f1701..465b0faac8 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/TokenChunkEvent.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/TokenChunkEvent.kt
@@ -22,7 +22,7 @@ internal interface TokenChunkEvent {
     val start: String?
     val end: String?
     val events: List<Event>
-    val stateEvents: List<Event>
+    val stateEvents: List<Event>?
 
     fun hasMore() = start != end
 }
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/TokenChunkEventPersistor.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/TokenChunkEventPersistor.kt
index 2a532c6bf5..1a497b8835 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/TokenChunkEventPersistor.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/timeline/TokenChunkEventPersistor.kt
@@ -156,7 +156,7 @@ internal class TokenChunkEventPersistor @Inject constructor(@SessionDatabase pri
                     }
                 }
         return if (receivedChunk.events.isEmpty()) {
-            if (receivedChunk.start != receivedChunk.end) {
+            if (receivedChunk.hasMore()) {
                 Result.SHOULD_FETCH_MORE
             } else {
                 Result.REACHED_END
@@ -196,7 +196,7 @@ internal class TokenChunkEventPersistor @Inject constructor(@SessionDatabase pri
 
         val now = System.currentTimeMillis()
 
-        for (stateEvent in stateEvents) {
+        stateEvents?.forEach { stateEvent ->
             val ageLocalTs = stateEvent.unsignedData?.age?.let { now - it }
             val stateEventEntity = stateEvent.toEntity(roomId, SendState.SYNCED, ageLocalTs).copyToRealmOrIgnore(realm, EventInsertType.PAGINATION)
             currentChunk.addStateEvent(roomId, stateEventEntity, direction)
@@ -205,9 +205,9 @@ internal class TokenChunkEventPersistor @Inject constructor(@SessionDatabase pri
             }
         }
         val eventIds = ArrayList<String>(eventList.size)
-        for (event in eventList) {
+        eventList.forEach { event ->
             if (event.eventId == null || event.senderId == null) {
-                continue
+                return@forEach
             }
             val ageLocalTs = event.unsignedData?.age?.let { now - it }
             eventIds.add(event.eventId)
diff --git a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/uploads/GetUploadsTask.kt b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/uploads/GetUploadsTask.kt
index 0c0e6a8ed0..b3e4a5aa05 100644
--- a/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/uploads/GetUploadsTask.kt
+++ b/matrix-sdk-android/src/main/java/org/matrix/android/sdk/internal/session/room/uploads/GetUploadsTask.kt
@@ -56,8 +56,8 @@ internal class DefaultGetUploadsTask @Inject constructor(
         private val roomAPI: RoomAPI,
         private val tokenStore: SyncTokenStore,
         @SessionDatabase private val monarchy: Monarchy,
-        private val globalErrorReceiver: GlobalErrorReceiver)
-    : GetUploadsTask {
+        private val globalErrorReceiver: GlobalErrorReceiver
+) : GetUploadsTask {
 
     override suspend fun execute(params: GetUploadsTask.Params): GetUploadsResult {
         val result: GetUploadsResult