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This solution utilizes Firebase’s Remote Config tool to allow Unity developers to modify their game’s behavior in real time, without requiring a fresh build & release cycle.

Once you've introduced this solution to your project, syncing field values between Remote Config and GameObjects in your game is as easy as adding a single Component and clicking a few buttons. You can even set values right from the Unity Editor, without even opening the Firebase console!

1. Requirements
2. Setup
   1. Create a Firebase project
   2. Download a google-credentials.json file
   3. Add the FirebaseRemoteConfigAutoSync Unity package
3. Patroller Demo Scene
   1. Using the custom editor
   2. Refreshing values during play
4. Using RemoteConfigSyncBehaviour
   1. Naming parameters
   2. Target selection parameters
5. What's Next

• A Unity® project with .NET 4.x Api level enabled. To enable .NET 4.x, go to Edit -> Project Settings -> Player -> Configuration and change Api Compatibility Level to .NET 4.x.

• If you don't already have a Firebase project, follow the Setup steps to create one.
• Download the Remote Config SDK from the Add a Firebase Unity SDK step.

• Go to the service accounts page on the Cloud console.
• Click the Actions dropdown from the firebase-adminsdk service account created when you first created your Firebase project.
• Select Create key to download a google-credentials.json file.
• Place the google-credentials.json file somewhere in your Project's Assets directory.
  • Important: Do not place this file anywhere below any Resources or Streaming Assets folders. This credential file contains authentication details to enable the Unity editor to call the Remote Config REST api, and is not intended to be included in a build binary. The base-level Assets directory is a good place for this, but any path without either of those strings will do.

• Download the latest FirebaseRemoteConfigAutoSync unitypackage file from the current-build directory.
• Import the unitypackage file at Assets -> Import Package -> Custom Package.
• Open the Remote Config Credentials editor window at Window -> Firebase -> Remote Config -> Credentials.
• Drag your google-credentials.json file from your Assets to the Google Credential File field.

Open Demo Scene 1. This is a simple little scene that generates a "patroller" object which will patrol between a set of points.

Select the Patrol prefab under Firebase_RemoteConfig/Demo/Demo 1/Prefabs.

Aside from the built-in Unity components like Transform and Mesh Renderer, the first Component in the Inspector window is RemoteConfigSyncBehaviour. This Component tells the Auto-Sync tool that this GameObject's other non-built-in Components (in this case, PatrolBehaviour) should be scanned for sync targets, and defines how to locate and name them.

Remote Config can sync values of the String, integer, double, or boolean primitive types.

In this example, this object's PatrolBehaviour field called Start Point will map to the Remote Config parameter PatrolBehaviour__StartPoint. However, the names generated can be modified with a few fields in RemoteConfigSyncBehaviour. See Using RemoteConfigSyncBehaviour for more details.

With the Patrol prefab selected in the Project view, make sure the RemoteConfigSyncBehaviour component is enabled and Sync All Fields is checked.

Open the custom Remote Config browser at Window -> Firebase -> Remote Config -> Sync.

Here you should see a list of Unmapped Parameters (empty unless you have used Remote Config before) and a list of Sync Targets.

The top group under Sync Targets should share the name PatrolBehaviour. It should contain a field called Sync All, and fields for each of its matching primitive fields in PatrolBehaviour.cs.

Click Sync All under PatrolBehaviour. All its sub-fields should not be highlighted and their checkboxes enabled.

Click Upload to Remote Config. Note the fields are no longer highlighted, but still checked.

Open the Firebase console, select your project, and go to the Remote Config tool under the Grow section.

Observe that the 4 primitive fields in PatrolBehaviour now have parameters with the prefix PatrolBehaviour__.

In the Unity Editor, click Play. Observe that an empty scene with 2 buttons appears. Click Spawn Patrol. A 3D sphere should appear and begin to patrol between 4 points in the scene.

This patrol object's field values should match both its default values and the values in Remote Config: starting from a point on the left, and patrolling through all 4 points at a speed of 2 and size of 1.

Now let's see Remote Config in action. Stop the scene and return to the Remote Config Sync editor.

In the Remote Config Sync editor window (NOT the Unity Inspector tab) and change the values to these:

• StartPoint: 1
• NumPoints: 2
• Speed: 5
• Size: .5

Note that they each appear highlighted as you change them from their values in Remote Config.

Click Upload to Remote Config and wait for them to no longer be highlighted.

Before we start the scene, let's confirm that the Prefab in the game itself has not changed.

Select the Patrol prefab again and note it still has its initial values.

Refresh the Firebase Console in your browser and confirm it has the new values we set.

Now click Play in the Unity Editor. When the scene starts, click Spawn Patrol. Observe that the patroller now starts on the right, patrols only 2 points, is half the size it once was and notably faster.

This is because when a GameObject with RemoteConfigSyncBehaviour is created or cloned, it checks its sync target fields against Remote Config parameters, and uses those values (when found) instead of its defaults.

With the game still playing, return to the Remote Config Sync scene and changes the values to:

• StartPoint: 2
• NumPoints: 3
• Speed: 1
• Size: 2

Click Upload to Remote Config. When it's done, return to the Game tab.

Click to spawn another patrol.

What happened? This new patrol has the same behavior as the last one!

This is because during gameplay, the static class managing sync targets will retrieve Remote Config values on startup, but won't refresh those values unless explicitly told to do so.

Click Refresh Values, and then spawn another patroller. Note that the new patroller has the newer values, while the existing ones retain their values when they were created. To see how this is working, you can examine the PatrolController script. It forces the SyncTargetManager to get refreshed Remote Config parameters when Refresh Values is clicked.

The RemoteConfigSyncBehaviour script is the Component you attach to GameObjects in your scene (and prefabs) whose fields you want to sync to and from Remote Config. Fields that are synced in this way are called "sync targets."

RemoteConfigSyncBehaviour has several custom fields that modify the way it locates and names its sync targets.

• Prefix Source: By default, the first section of a sync target's prefix is the Component it is attached to. This allows cloned copies of a prefab (whose names are modified with "(Clone)" when they are created) to sync to the same value. But this isn't always the desired behavior. Setting this field to Game Object uses the name of the GameObject instead of the Component (in this case, it would be Sync Demo Object). Or, select Custom to define a static prefix (or no prefix at all).
  • Key Prefix: This field only appears when Prefix Source is set to Custom. Use it to define the static prefix desired.

The other two fields on RemoteConfigSyncBehaviour control the discovery of its sync targets.

By default, only fields with the RemoteConfigSync attribute are synced. This allows fine-grained control over which fields should and should not be synced with Remote Config.

[RemoteConfigSync] can be applied to the primitive types that Remote Config supports, or to Serializable data objects which contain fields of those types (and so on).

When a Serializable object has the [RemoteConfigSync] attribute, its individual fields do not need the [RemoteConfigSync] attribute themselves.

• Sync All Fields: If this RemoteConfigSyncBehaviour field is enabled, then ALL primitive types found under this GameObject's Components are valid sync targets, regardless of whether they have the [RemoteConfigSync] attribute or not. When using this setting, you can tell Auto-Sync to specifically skip a field with the RemoteConfigSkipSync attribute.
  • Include Sub Fields: This field only appears if Sync All Fields is checked. For efficiency reasons, even with Sync All Fields enabled Auto-Sync still won't go digging through complex object children that don't have the [RemoteConfigSync] attribute unless Include Sub Fields is also checked. This tells Auto-Sync to look through this Object's entire field hierarchy for sync targets, letting nothing stop it except for [RemoteConfigSkipSync].

As a rule of thumb: If you want to specify which fields to sync, leave Sync All Fields false and use the [RemoteConfigSync] attribute on those fields. If you want to specify which fields NOT to include, check Sync All Fields and specify fields to skip with [RemoteConfigSkipSync].

To see how these fields modify the sync targets found by the Remote Config Sync window, open Demo Scene 2 and select Demo Sync Object in the Hierarchy tab. Try selecting different combinations of RemoteConfigSyncBehaviour and observing how it changes the items in the Remote Config Sync tab.

The custom editor has several other capabilities as well. It can be used to control/view different values for parameters based on any Remote Config Conditions you've created.

There are also buttons in the default and condition tabs of the Remote Config Sync window to set all the local targets from Remote Config, or to set that column's sync values from the local values. You can experiment with this by changing the values on local targets (like the Patrol prefab in Demo Scene 1, or the Sync Demo Object in Demo Scene 2), and then clicking Set From Local in the given column, or vise versa.

Check out the other solutions in Firebase Unity Solutions for even more tools to use Firebase in your Unity project!