Add the Firebase Admin SDK to your server

Node.js

The Firebase Admin Node.js SDK is available on npm. If you don't already have a package.json file, create one via npm init. Next, install the firebase-admin npm package and save it to your package.json:

npm install firebase-admin --save

To use the module in your application, require it from any JavaScript file:

const { initializeApp } = require('firebase-admin/app');

If you are using ES2015, you can import the module:

import { initializeApp } from 'firebase-admin/app';

Java

The Firebase Admin Java SDK is published to the Maven central repository. To install the library, declare it as a dependency in your build.gradle file:

dependencies {
  implementation 'com.google.firebase:firebase-admin:9.4.1'
}

If you use Maven to build your application, you can add the following dependency to your pom.xml:

<dependency>
  <groupId>com.google.firebase</groupId>
  <artifactId>firebase-admin</artifactId>
  <version>9.4.1</version>
</dependency>

Python

The Firebase Admin Python SDK is available via pip. You can install the library for all users via sudo:

sudo pip install firebase-admin

Or, you can install the library for just the current user by passing the --user flag:

pip install --user firebase-admin

Go

The Go Admin SDK can be installed using the go get utility:

# Install the latest version:
go get firebase.google.com/go/v4@latest

# Or install a specific version:
go get firebase.google.com/go/v4@4.15.0

C#

The .NET Admin SDK can be installed using the .NET package manager:

Install-Package FirebaseAdmin -Version 3.0.1

Alternatively, install it using the dotnet command-line utility:

dotnet add package FirebaseAdmin --version 3.0.1

Or, you can install it by adding the following package reference entry to your .csproj file:

<ItemGroup>
  <PackageReference Include="FirebaseAdmin" Version="3.0.1" />
</ItemGroup>

Node.js

const app = initializeApp();

Java

FirebaseApp.initializeApp();

Python

default_app = firebase_admin.initialize_app()

Go

app, err := firebase.NewApp(context.Background(), nil)
if err != nil {
	log.Fatalf("error initializing app: %v\n", err)
}
init.go

C#

FirebaseApp.Create();

Node.js

const myRefreshToken = '...'; // Get refresh token from OAuth2 flow

initializeApp({
  credential: refreshToken(myRefreshToken),
  databaseURL: 'https://<DATABASE_NAME>.firebaseio.com'
});

Java

FileInputStream refreshToken = new FileInputStream("path/to/refreshToken.json");

FirebaseOptions options = FirebaseOptions.builder()
    .setCredentials(GoogleCredentials.fromStream(refreshToken))
    .setDatabaseUrl("https://<DATABASE_NAME>.firebaseio.com/")
    .build();

FirebaseApp.initializeApp(options);

Python

cred = credentials.RefreshToken('path/to/refreshToken.json')
default_app = firebase_admin.initialize_app(cred)

Go

opt := option.WithCredentialsFile("path/to/refreshToken.json")
config := &firebase.Config{ProjectID: "my-project-id"}
app, err := firebase.NewApp(context.Background(), config, opt)
if err != nil {
	log.Fatalf("error initializing app: %v\n", err)
}
init.go

C#

FirebaseApp.Create(new AppOptions()
{
    Credential = GoogleCredential.FromFile("path/to/refreshToken.json"),
});

Linux or macOS

export GOOGLE_APPLICATION_CREDENTIALS="/home/user/Downloads/service-account-file.json"

Windows

With PowerShell:

$env:GOOGLE_APPLICATION_CREDENTIALS="C:\Users\username\Downloads\service-account-file.json"

Node.js

initializeApp({
    credential: applicationDefault(),
    databaseURL: 'https://<DATABASE_NAME>.firebaseio.com'
});

Java

FirebaseOptions options = FirebaseOptions.builder()
    .setCredentials(GoogleCredentials.getApplicationDefault())
    .setDatabaseUrl("https://<DATABASE_NAME>.firebaseio.com/")
    .build();

FirebaseApp.initializeApp(options);

Python

default_app = firebase_admin.initialize_app()

Go

app, err := firebase.NewApp(context.Background(), nil)
if err != nil {
	log.Fatalf("error initializing app: %v\n", err)
}
init.go

C#

FirebaseApp.Create(new AppOptions()
{
    Credential = GoogleCredential.GetApplicationDefault(),
    ProjectId = "my-project-id",
});
FirebaseAppSnippets.cs

Node.js

// Initialize the default app
const defaultApp = initializeApp(defaultAppConfig);

console.log(defaultApp.name);  // '[DEFAULT]'

// Retrieve services via the defaultApp variable...
let defaultAuth = getAuth(defaultApp);
let defaultDatabase = getDatabase(defaultApp);

// ... or use the equivalent shorthand notation
defaultAuth = getAuth();
defaultDatabase = getDatabase();

Java

// Initialize the default app
FirebaseApp defaultApp = FirebaseApp.initializeApp(defaultOptions);

System.out.println(defaultApp.getName());  // "[DEFAULT]"

// Retrieve services by passing the defaultApp variable...
FirebaseAuth defaultAuth = FirebaseAuth.getInstance(defaultApp);
FirebaseDatabase defaultDatabase = FirebaseDatabase.getInstance(defaultApp);

// ... or use the equivalent shorthand notation
defaultAuth = FirebaseAuth.getInstance();
defaultDatabase = FirebaseDatabase.getInstance();

Python

# Import the Firebase service
from firebase_admin import auth

# Initialize the default app
default_app = firebase_admin.initialize_app(cred)
print(default_app.name)  # "[DEFAULT]"

# Retrieve services via the auth package...
# auth.create_custom_token(...)

Go

// Initialize default app
app, err := firebase.NewApp(context.Background(), nil)
if err != nil {
	log.Fatalf("error initializing app: %v\n", err)
}

// Access auth service from the default app
client, err := app.Auth(context.Background())
if err != nil {
	log.Fatalf("error getting Auth client: %v\n", err)
}
init.go

C#

// Initialize the default app
var defaultApp = FirebaseApp.Create(new AppOptions()
{
    Credential = GoogleCredential.GetApplicationDefault(),
});
Console.WriteLine(defaultApp.Name); // "[DEFAULT]"

// Retrieve services by passing the defaultApp variable...
var defaultAuth = FirebaseAuth.GetAuth(defaultApp);

// ... or use the equivalent shorthand notation
defaultAuth = FirebaseAuth.DefaultInstance;

Node.js

// Initialize the default app
initializeApp(defaultAppConfig);

// Initialize another app with a different config
var otherApp = initializeApp(otherAppConfig, 'other');

console.log(getApp().name);  // '[DEFAULT]'
console.log(otherApp.name);     // 'other'

// Use the shorthand notation to retrieve the default app's services
const defaultAuth = getAuth();
const defaultDatabase = getDatabase();

// Use the otherApp variable to retrieve the other app's services
const otherAuth = getAuth(otherApp);
const otherDatabase = getDatabase(otherApp);

Java

// Initialize the default app
FirebaseApp defaultApp = FirebaseApp.initializeApp(defaultOptions);

// Initialize another app with a different config
FirebaseApp otherApp = FirebaseApp.initializeApp(otherAppConfig, "other");

System.out.println(defaultApp.getName());  // "[DEFAULT]"
System.out.println(otherApp.getName());    // "other"

// Use the shorthand notation to retrieve the default app's services
FirebaseAuth defaultAuth = FirebaseAuth.getInstance();
FirebaseDatabase defaultDatabase = FirebaseDatabase.getInstance();

// Use the otherApp variable to retrieve the other app's services
FirebaseAuth otherAuth = FirebaseAuth.getInstance(otherApp);
FirebaseDatabase otherDatabase = FirebaseDatabase.getInstance(otherApp);

Python

# Initialize the default app
default_app = firebase_admin.initialize_app(cred)

#  Initialize another app with a different config
other_app = firebase_admin.initialize_app(cred, name='other')

print(default_app.name)    # "[DEFAULT]"
print(other_app.name)      # "other"

# Retrieve default services via the auth package...
# auth.create_custom_token(...)

# Use the `app` argument to retrieve the other app's services
# auth.create_custom_token(..., app=other_app)

Go

// Initialize the default app
defaultApp, err := firebase.NewApp(context.Background(), nil)
if err != nil {
	log.Fatalf("error initializing app: %v\n", err)
}

// Initialize another app with a different config
opt := option.WithCredentialsFile("service-account-other.json")
otherApp, err := firebase.NewApp(context.Background(), nil, opt)
if err != nil {
	log.Fatalf("error initializing app: %v\n", err)
}

// Access Auth service from default app
defaultClient, err := defaultApp.Auth(context.Background())
if err != nil {
	log.Fatalf("error getting Auth client: %v\n", err)
}

// Access auth service from other app
otherClient, err := otherApp.Auth(context.Background())
if err != nil {
	log.Fatalf("error getting Auth client: %v\n", err)
}
init.go

C#

// Initialize the default app
var defaultApp = FirebaseApp.Create(defaultOptions);

// Initialize another app with a different config
var otherApp = FirebaseApp.Create(otherAppConfig, "other");

Console.WriteLine(defaultApp.Name); // "[DEFAULT]"
Console.WriteLine(otherApp.Name); // "other"

// Use the shorthand notation to retrieve the default app's services
var defaultAuth = FirebaseAuth.DefaultInstance;

// Use the otherApp variable to retrieve the other app's services
var otherAuth = FirebaseAuth.GetAuth(otherApp);

gcloud

# Check the existing access scopes
gcloud compute instances describe [INSTANCE_NAME] --format json

# The above command returns the service account information. For example:
  "serviceAccounts": [
   {
    "email": "your.gserviceaccount.com",
    "scopes": [
     "https://www.googleapis.com/auth/cloud-platform",
     "https://www.googleapis.com/auth/userinfo.email"
     ]
    }
  ],

# Stop the VM, then run the following command, using the service account
# that gcloud returned when you checked the scopes.

gcloud compute instances set-service-account [INSTANCE_NAME] --service-account "your.gserviceaccount.com" --scopes "https://www.googleapis.com/auth/firebase.database,https://www.googleapis.com/auth/userinfo.email"

gcloud

gcloud auth application-default login --client-id-file=[/path/to/client/id/file]

Node.js

import { initializeApp, applicationDefault } from 'firebase-admin/app';

initializeApp({
  credential: applicationDefault(),
  projectId: '<FIREBASE_PROJECT_ID>',
});

Java

FirebaseOptions options = FirebaseOptions.builder()
    .setCredentials(GoogleCredentials.getApplicationDefault())
    .setProjectId("<FIREBASE_PROJECT_ID>")
    .build();

FirebaseApp.initializeApp(options);

Python

app_options = {'projectId': '<FIREBASE_PROJECT_ID>'}
default_app = firebase_admin.initialize_app(options=app_options)

Go

config := &firebase.Config{ProjectID: "<FIREBASE_PROJECT_ID>"}
app, err := firebase.NewApp(context.Background(), config)
if err != nil {
        log.Fatalf("error initializing app: %v\n", err)
}

C#

FirebaseApp.Create(new AppOptions()
{
    Credential = GoogleCredential.GetApplicationDefault(),
    ProjectId = "<FIREBASE_PROJECT_ID>",
});