How to Use Firebase with Unity

1// Import via Unity Editor:
2// Assets > Import Package > Custom Package
3// Select FirebaseAuth.unitypackage
4// Select FirebaseFirestore.unitypackage
5// Select FirebaseAnalytics.unitypackage

1// File locations:
2// Assets/google-services.json      (Android)
3// Assets/GoogleService-Info.plist   (iOS)

1// Unity Editor menu:
2// Assets > External Dependency Manager > Android Resolver > Force Resolve
3// Assets > External Dependency Manager > iOS Resolver > Install Cocoapods

1// Scripts/FirebaseInit.cs
2using UnityEngine;
3using Firebase;
4using Firebase.Extensions;
5
6public class FirebaseInit : MonoBehaviour
7{
8    public static bool IsReady { get; private set; }
9
10    void Start()
11    {
12        FirebaseApp.CheckAndFixDependenciesAsync().ContinueWithOnMainThread(task =>
13        {
14            if (task.Result == DependencyStatus.Available)
15            {
16                Debug.Log("Firebase initialized successfully");
17                IsReady = true;
18            }
19            else
20            {
21                Debug.LogError($"Firebase dependency error: {task.Result}");
22            }
23        });
24    }
25}

1// Scripts/AuthManager.cs
2using UnityEngine;
3using Firebase.Auth;
4using Firebase.Extensions;
5
6public class AuthManager : MonoBehaviour
7{
8    private FirebaseAuth auth;
9
10    void Start()
11    {
12        auth = FirebaseAuth.DefaultInstance;
13    }
14
15    public void Register(string email, string password)
16    {
17        auth.CreateUserWithEmailAndPasswordAsync(email, password)
18            .ContinueWithOnMainThread(task =>
19            {
20                if (task.Exception != null)
21                {
22                    Debug.LogError($"Registration failed: {task.Exception.Message}");
23                    return;
24                }
25                Debug.Log($"User created: {task.Result.User.UserId}");
26            });
27    }
28
29    public void SignIn(string email, string password)
30    {
31        auth.SignInWithEmailAndPasswordAsync(email, password)
32            .ContinueWithOnMainThread(task =>
33            {
34                if (task.Exception != null)
35                {
36                    Debug.LogError($"Sign-in failed: {task.Exception.Message}");
37                    return;
38                }
39                Debug.Log($"Signed in: {task.Result.User.Email}");
40            });
41    }
42}

1// Scripts/FirestoreManager.cs
2using UnityEngine;
3using Firebase.Firestore;
4using Firebase.Extensions;
5using System.Collections.Generic;
6
7public class FirestoreManager : MonoBehaviour
8{
9    private FirebaseFirestore db;
10
11    void Start()
12    {
13        db = FirebaseFirestore.DefaultInstance;
14    }
15
16    public void SavePlayerScore(string playerId, int score)
17    {
18        var data = new Dictionary<string, object>
19        {
20            { "score", score },
21            { "updatedAt", FieldValue.ServerTimestamp }
22        };
23
24        db.Collection("players").Document(playerId).SetAsync(data)
25            .ContinueWithOnMainThread(task =>
26            {
27                if (task.Exception != null)
28                    Debug.LogError($"Save failed: {task.Exception.Message}");
29                else
30                    Debug.Log("Score saved");
31            });
32    }
33
34    public void GetPlayerScore(string playerId)
35    {
36        db.Collection("players").Document(playerId).GetSnapshotAsync()
37            .ContinueWithOnMainThread(task =>
38            {
39                if (task.Result.Exists)
40                {
41                    var data = task.Result.ToDictionary();
42                    Debug.Log($"Score: {data["score"]}");
43                }
44            });
45    }
46}