How to Upload Binary Content Directly from your Game

You can give your players the ability to upload binary content to be hosted on the GameSparks platform and, from there, shareable with other players. The way to do this is fairly straightforward and you must complete the following steps:

  1. Request a URL from the platform to which you can upload the content.
  2. Upload the content to the URL provided by the platform.
  3. Once content has been uploaded, you'll want the player (or other players) to be able to retrieve the content for use.

In this exercise we'll run through how you complete each of these steps with the GameSparks API and demonstrate this using the Test Harness. To finish, there is a brief note on using the GameSparks SDKs to perform these steps (which we've streamlined behind the scenes to make your life easier).

Upload File Size Limit? For the file size limit imposed on uploaded content, see System Limits.

Get an Upload URL

The first step is to get an upload URL - you need somewhere to post your content. If you're following these steps in the Test Harness, the GetUploadUrlRequest is available under the Upload category (make sure you've authenticated as a player before making the first request).

A GetUploadUrlRequest made by an authenticated player will result in a response containing a url attribute.

URL Attribute has limited Lifespan! Upload URLs are one-shot URLs that expire after a matter of minutes so don't hang onto them - if you don't use it right away, throw it away and request another one.

  "@class": ".GetUploadUrlRequest"

 "@class": ".GetUploadUrlResponse",
 "url": ""

Upload the Content

Now that you have the upload URL you need to post the file. This is done using a multipart/form-data post - we'd recommend checking it out in the Test Harness because we've provided a widget that will do this for you. When using the SDKs, see SDK Usage section below.

1. In the portal, navigate to Configurator>Test Harness.

2. Authenticate as a player you've registered previously.

3. Under Requests, click on Upload and select GetUploadUrlRequest.

Metadata? Note that the GetUploadUrlRequest has an uploadData parameter. You can use this to enter some metadata, which will be stored against the player's uploaded binary content. For this example, you can remove this parameter before submitting the request.

4. Remove the uploadData parameter and submit the GetUploadUrlRequest. You'll see a GetUploadUrlResponse in the Inspector window and the upload Url is automatically entered into the URL field:

5. Under File, click Browse to select the file you want to upload as binary content to the platform.

6. When you've selected the file you want to upload, click Upload:

Being an HTTP POST, this is not done through the WebSocket. However, when the upload is complete, the authenticated WebSocket that was used to request the upload URL will receive an UploadCompleteMessage indicating that the upload was successful:

  "@class": ".UploadCompleteMessage",
  "messageId": "5832edaf3a32df04983a8960",
  "notification": true,
  "playerId": "5818aef23a32df04ae8d53ed",
  "summary": "Your upload is complete",
  "uploadData": {
    "fileName": "634c80176da1458d965692c87c3a8e68-My Document.txt",
    "uploadId": "634c80176da1458d965692c87c3a8e68",
    "fileSize": 30,
    "origFileName": "My Document.txt",
    "playerId": "5818aef23a32df04ae8d53ed"
  "uploadId": "634c80176da1458d965692c87c3a8e68"

Within the message is an uploadData attribute which contains all the data about the upload:

Retrieve the Content

The final step is to actually retrieve the content that has been uploaded.

1. In the Test Harness click Misc under Requests and select GetUploadedRequest which takes an uploadId (which we received from the UploadCompleteMessage):

  "@class": ".GetUploadedRequest",

A GetUploadedResponse is returned, which contains a URL we can use to download the content. As before, this URL is time-sensitive so don't hang onto it for long - request one as you need it.

  "@class": ".GetUploadedResponse",
  "size": 30,
  "url": ""

2. Go ahead and test the URL you receive by pasting it into your address bar in the browser. You should be able to download the content you uploaded in the earlier step.

uploadId not Tied to One Player! The uploadId is not tied to a specific player, so if you were to send that uploadId to another player, the other player could also use it to request a download URL. This means you can allow your players to share content by sending the uploadIds to other players.

Deleting Uploaded Files

When managing your uploaded files, you can use the deleteUploadedFile SparkFiles method to delete uploaded files.

SDK Usage


For completeness we expose the method getUploadUrlRequest to build the request object to get a URL to post the upload to. However, there's an additional method we provide called uploadFile that takes a file, fileName, and optional metadata about the upload. This wraps the request to get an upload URL and the subsequent upload of the file and presents them as a single operation(Unity only).
        .send(new GSEventConsumer<GSResponseBuilder.GetUploadUrlResponse>() {
            public void onEvent(GSResponseBuilder.GetUploadUrlResponse getUploadUrlResponse) {
                if (!getUploadUrlResponse.hasErrors()) {
                    System.out.println("upload URL is " + getUploadUrlResponse.getUrl());


As with the upload, we expose the method getUploadedRequest to build the request object to get a URL to download the file. However, there's an additional method getUploadedFile which takes the uploadId and wraps up requesting the download URL and performing the download itself and presents them as a single operation.
        .setUploadId(uploadId).send(new GSEventConsumer<GSResponseBuilder.GetUploadUrlResponse>() {
    public void onEvent(GSResponseBuilder.GetUploadedResponse getUploadedResponse) {



We haven't yet added the above convenience methods for any of the SDKs apart from the Android and Unity SDKs, so for now you'll need to implement the multipart post yourself. We won't go into the details of exactly how to implement this here because there are many great resources already available that cover this. What you do need to know is that the parameter name against which the binary content is posted is file.