Add version to rpc requests (#605)

* Add version to rpc requests

* spotless

+---
+"client-sdk-android": patch
+---
+
+Add version number to rpc requests

@@ -35,6 +35,7 @@ import io.livekit.android.room.RTCEngine
 import io.livekit.android.room.Room
 import io.livekit.android.room.TrackBitrateInfo
 import io.livekit.android.room.isSVCCodec
+import io.livekit.android.room.rpc.RpcManager
 import io.livekit.android.room.track.DataPublishReliability
 import io.livekit.android.room.track.LocalAudioTrack
 import io.livekit.android.room.track.LocalAudioTrackOptions
@@ -986,6 +987,7 @@ internal constructor(
                 this.method = method
                 this.payload = payload
                 this.responseTimeoutMs = responseTimeout.inWholeMilliseconds.toUInt().toInt()
+                this.version = RpcManager.RPC_VERSION
                 build()
             }
             build()
@@ -1071,7 +1073,7 @@ internal constructor(
     ) {
         publishRpcAck(callerIdentity, requestId)
 
-        if (version != 1) {
+        if (version != RpcManager.RPC_VERSION) {
             publishRpcResponse(
                 destinationIdentity = callerIdentity,
                 requestId = requestId,

+/*
+ * Copyright 2025 LiveKit, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package io.livekit.android.room.rpc
+
+class RpcManager {
+    companion object {
+        const val RPC_VERSION = 1
+    }
+}

@@ -18,6 +18,7 @@ package io.livekit.android.room.participant
 
 import com.google.protobuf.ByteString
 import io.livekit.android.room.RTCEngine
+import io.livekit.android.room.rpc.RpcManager
 import io.livekit.android.rpc.RpcError
 import io.livekit.android.test.MockE2ETest
 import io.livekit.android.test.mock.MockDataChannel
@@ -31,6 +32,7 @@ import kotlinx.coroutines.launch
 import livekit.LivekitModels
 import livekit.LivekitRtc
 import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
 import org.junit.Assert.assertTrue
 import org.junit.Test
 import org.junit.runner.RunWith
@@ -147,6 +149,43 @@ class RpcMockE2ETest : MockE2ETest() {
     }
 
     @Test
+    fun handleRpcRequestWithNoVersion() = runTest {
+        connect()
+
+        var methodCalled = false
+        room.localParticipant.registerRpcMethod("hello") {
+            methodCalled = true
+            return@registerRpcMethod "hello back"
+        }
+
+        val noVersionRequest = with(TestData.DATA_PACKET_RPC_REQUEST.toBuilder()) {
+            rpcRequest = with(rpcRequest.toBuilder()) {
+                clearVersion()
+                build()
+            }
+            build()
+        }
+        subDataChannel.simulateBufferReceived(noVersionRequest.toDataChannelBuffer())
+
+        coroutineRule.dispatcher.scheduler.advanceUntilIdle()
+
+        assertFalse(methodCalled)
+        // Check that ack and response were sent
+        val buffers = pubDataChannel.sentBuffers
+        assertEquals(2, buffers.size)
+
+        val ackBuffer = LivekitModels.DataPacket.parseFrom(ByteString.copyFrom(buffers[0].data))
+        val responseBuffer = LivekitModels.DataPacket.parseFrom(ByteString.copyFrom(buffers[1].data))
+
+        assertTrue(ackBuffer.hasRpcAck())
+        assertEquals(TestData.DATA_PACKET_RPC_REQUEST.rpcRequest.id, ackBuffer.rpcAck.requestId)
+
+        assertTrue(responseBuffer.hasRpcResponse())
+        assertEquals(TestData.DATA_PACKET_RPC_REQUEST.rpcRequest.id, responseBuffer.rpcResponse.requestId)
+        assertEquals(RpcError.BuiltinRpcError.UNSUPPORTED_VERSION.create(), RpcError.fromProto(responseBuffer.rpcResponse.error))
+    }
+
+    @Test
     fun handleRpcRequestWithNoHandler() = runTest {
         connect()
 
@@ -190,6 +229,7 @@ class RpcMockE2ETest : MockE2ETest() {
         assertTrue(requestBuffer.hasRpcRequest())
         assertEquals("hello", requestBuffer.rpcRequest.method)
         assertEquals("hello world", requestBuffer.rpcRequest.payload)
+        assertEquals(RpcManager.RPC_VERSION, requestBuffer.rpcRequest.version)
 
         val requestId = requestBuffer.rpcRequest.id