`SerializationException` on "goAway" message in LiveSession

[Kick-snare]

[READ] Step 1: Are you in the right place?

Issues filed here should be about bugs in the code in this repository. If you have a general
question, need help debugging, or fall into some other category use one of these other channels:

• For general technical questions, post a question on StackOverflow
  with the firebase tag.
• For general Firebase discussion, use the
  firebase-talk google group.
• For help troubleshooting your application that does not fall under one of the above categories,
  reach out to the personalized Firebase support channel.

[REQUIRED] Step 2: Describe your environment

• Android Studio version: Otter
• Firebase Component: Gemini Live / LiveSession
• Component version: BOM 34.7.0 (firebase ai logics 17.7.0)
• Device: Pixel 9
• OS: Android 16 Beta QPR2
• Compile/Target SDK: 36

[REQUIRED] Step 3: Describe the problem

Description:

I am experiencing a fatal crash when using LiveSession in the Firebase AI SDK. It appears that when the server decides to close the connection (likely due to timeout or session expiry), it sends a JSON message containing the key "goAway".

The LiveServerMessageSerializer does not recognize this key, resulting in a SerializationException. Since this exception occurs on the internal networkScope (inside processModelResponses), it cannot be caught by the caller's try-catch block around startAudioConversation, causing the entire application to crash (Force Close) unless a global UncaughtExceptionHandler is implemented.

(use vertexAI backend)

Stack Trace:

FATAL EXCEPTION: Firebase Blocking Thread #1
Process: com.android.ai.catalog, PID: 17127
com.google.firebase.ai.type.SerializationException: Unknown LiveServerMessage response type. Keys found: [goAway]
	at com.google.firebase.ai.type.LiveServerMessageSerializer.selectDeserializer(LiveServerMessage.kt:206)
	at kotlinx.serialization.json.JsonContentPolymorphicSerializer.deserialize(JsonContentPolymorphicSerializer.kt:93)
	at kotlinx.serialization.json.internal.StreamingJsonDecoder.decodeSerializableValue(StreamingJsonDecoder.kt:69)
	at kotlinx.serialization.json.Json.decodeFromString(Json.kt:165)
	at com.google.firebase.ai.type.LiveSession$receive$1$1.invokeSuspend(LiveSession.kt:687)
	at com.google.firebase.ai.type.LiveSession$receive$1$1.invoke(Unknown Source:8)
    ...
	at kotlinx.coroutines.flow.FlowKt__CollectKt$launchIn$1.invokeSuspend(Collect.kt:46)
	at kotlin.coroutines.jvm.internal.BaseContinuationImpl.resumeWith(ContinuationImpl.kt:33)
	at kotlinx.coroutines.DispatchedTask.run(DispatchedTask.kt:100)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1154)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:652)
	at java.lang.Thread.run(Thread.java:1563)

Steps to reproduce:

1. Initialize GenerativeModel with liveModel backend.
2. Connect to the session and start the conversation (session.startAudioConversation()).
3. Keep the session open until the server initiates a disconnect (or simulate a server-side "goAway" message).
4. The app crashes with the SerializationException on a background thread.

Relevant Code:

viewModelScope.launch {
    // Even with try-catch here, the crash cannot be caught because it happens on the SDK's internal networkScope
    try {
        val session = generativeModel.connect()
        session.startAudioConversation(functionCallHandler = ::handleFunctionCall) 
    } catch (e: Exception) {
        Log.e("Gemini", "This does not catch the crash", e)
    }
}

Additional Requests / Suggestions

Since this issue involves how the SDK handles server signals and media, I would like to propose the following improvements:

• "goAway" Message Handling & Session Extension Instead of crashing, the SDK should handle the "goAway" message gracefully.
  • Feature Request: Expose this event to the client so we can handle session termination properly.
  • Feature Request: Provide a mechanism to extend the session upon receiving this warning, or allow seamless reconnection without losing context.

or just add goAwayHander param to LiveAudioConversationConfig constructor to handle goAway signal

[Kick-snare]

I've analyzed the root cause and implemented a fix including unit tests.
submitted a PR for this: #7649

[lehcar09]

Hi @Kick-snare, thank you for reaching out and raising this issue. I was able to reproduce the exception with the description you shared. I will raise this to our engineers along with the PR you submit and see what we can do here. Thanks!