Server Setup

🚀 Step-by-Step Guide: Setting Up Your FCM Sender Server

Follow these instructions carefully to configure and deploy your Google Apps Script as a secure Firebase Cloud Messaging (FCM) sender server.

---

🛠️ Step 1: Create a New Apps Script Project

1.1 Access Google Apps Script

• Go to the Google Apps Script Home.
• Click on New Project.
• Paste this fcm_sender.js

---

1.2 Project Configuration

• Rename your project to something recognizable (e.g., FCM Sender Server).
• Navigate to the left sidebar and click on Project Settings (the gear icon ⚙️).

---

1.3 Expose the Manifest File

• Check the box for Show "appsscript.json" manifest file in editor.

---

1.4 Configure OAuth Scopes

• Return to the Editor tab and open the newly visible appsscript.json file.
• Inside the file configuration, add the script external request field to your "oauthScopes".
• Save the file.

"oauthScopes": [
  "https://www.googleapis.com/auth/script.external_request"
]

---

🔑 Step 2: Setup Script Credentials

2.1 Initialize Your Script

• Open your main script file (usually Code.gs).
• Paste your server script template into the editor.
• Define your custom SECRET_KEY.

---

2.2 Retrieve Firebase Project Credentials

• Navigate to the Firebase Console.
• Click the gear icon next to "Project Overview" and select Project settings.

---

2.3 Extract Project ID

• Copy your unique Project ID and paste it into the respective variable within your Apps Script code.

---

2.4 Access Service Accounts

• Inside Firebase Project Settings, switch to the Service accounts tab.

---

2.5 Generate Private Key

• Scroll down and click the Generate new private key button.
• Confirm and download the resulting .json key file to your local machine.

---

2.6 Link Service Account to Script

• Open the downloaded .json file, copy its entire contents, and paste it directly into the SERVICE_ACCOUNT object variable in your script.

---

2.7 Run Setup Test

• Double-check that all 3 critical variables (SECRET_KEY, PROJECT_ID, and SERVICE_ACCOUNT) are filled out, then Save the file.
• Select the testSetup function from the top toolbar dropdown.
• Click Run.

---

🧪 Step 3: Authorize and Test Your Script

⚠️ Note: On your first execution, Google requires an explicit permissions review. Follow the bypass steps below.

3.1 Review Permissions

• When the authorization dialog appears, click Review permissions.

---

3.2 Advanced Options

• Select your Google Account, then click on the Advanced link at the bottom of the prompt.

---

3.3 Bypass Warning

• Click the safety bypass link labeled Go to FCM Sender Server (unsafe).

---

3.4 Confirm Access

• Review the requested permissions scopes and click Allow / Continue to grant execution rights.

---

🎉 Test Verification Success

• Check the execution log window at the bottom of your screen.
• If the log displays FCM response: 400 • Auth OK, your environment is fully authorized and properly linked to Firebase.

---

🌐 Step 4: Web App Project Deployment

4.1 Initiate Deployment

• Click the Deploy button in the top right corner.
• Choose New deployment from the dropdown menu.

---

4.2 Select Deployment Type

• Click the Gear icon next to Select type.
• Choose Web app from the options list.

---

4.3 Configure Deployment Settings

Set up your parameters exactly as follows to ensure external accessibility:

• Description: Add a short note (e.g., FCM Sender HTTP v1 API _V1.0.0).
• Execute as: Set to Me (your-email).
• Who has access: Set to Anyone.
• Click Deploy.

---

📋 Final Step

• Your web server deployment is complete!
• Copy the generated Web app URL from the screen. This URL will serve as your live API endpoint inside your extension configuration.