Enabling Pre-Launch Functionality in Your Custom Client

To use the Pre-Launch functionality in your custom client, you must upgrade the client to the new 5.0.1 SDK version. Once upgraded, follow these steps to integrate Pre-Launch into your application.

Updating the Launch Request Hook

In your main App.tsx file, where you issue a launch request, import the additional preLaunchRequest hook:

const [status, launchRequest, queueLaunchRequest, resetLaunchRequest, preLaunchRequest] = useLaunchRequest(
  platform,
  modelDefinition,
  launchRequestOptions
);

Adding the Pre-Launch Effect

Next, add the following useEffect section to handle the pre-launch request:

useEffect(() => {
  const handlePreLaunchRequest = async () => {
    if (modelDefinition && modelDefinition.type !== ModelDefinitionType.Undefined) {
      if (clientOptions.LaunchType !== 'local') {
        try {
          await preLaunchRequest(20000);
        } catch (err) {
          setLaunchRequestError(err);
        }
      }
    }
  };
  handlePreLaunchRequest();
}, [modelDefinition, preLaunchRequest]);

How Pre-Launch Works

You do not need to modify any other part of your custom client code.

The Pre-Launch request is useful if you want to start a stream in the background and consume it in response to a user interaction. This can significantly reduce the perceived launch time, improving user experience.

Key considerations:

The preLaunchRequest(20000) parameter is in milliseconds. This specifies how long the pre-launched session remains active.
The maximum allowed pre-launch duration is 5 minutes.
If the user does not start the session within the specified time, the pre-launched session will terminate.
If the user starts the session after the pre-launch duration has expired, the launch request will follow the normal route.
If the user starts the session within the pre-launch window, the time to the first frame will be significantly faster.
If the user requests the stream before it is ready, the system will attempt to join the background launch request in progress, reducing perceived wait time.

Step 4: Reset to Launch View on Session Completion

In the App.tsx, monitor the stream status, and reset to initial launch view when the session ends StreamerStatus.Completed.

if (streamerStatus === StreamerStatus.Completed) {
  return <LaunchView Launch={launch} />;
}

Important Notes

Since the pre-launch functionality keeps the game in a running state, you must ensure the game can wait for the client to connect if needed.
If your game requires the client to send an initial message before proceeding, you are responsible for implementing a suspension mode that waits for the client’s connection.
For details on implementing messaging between the client and the game, refer to the following articles: