Lighthouse API

Lighthouse is a Firebase Cloud Functions service that handles push notifications for mobile applications. It provides a simple REST API to send FCM notifications to users.

Quick Start

npm install
npm run serve    # Local development
npm run deploy   # Deploy to Firebase

API Endpoints

Health Check

GET /health

Returns service status and timestamp.

Send Notification

POST /notification
Content-Type: application/json

{
  "targetUserId": "user123",
  "type": "added_friend",
  "fromUserId": "user456"
}

Notification Types

Type	Title	Description
added_friend	"New Friend!"	Friend request notification
bill_created	"New Bill Created"	New bill notification
bill_settled	"Bill Settled"	Bill settlement notification

Requirements

• Users must exist in Firestore users collection
• Users must have fcmToken field for notifications
• Users must have username field

Response Format

Success:

{
  "success": true,
  "messageId": "fcm-message-id",
  "sentTo": "user123",
  "type": "added_friend"
}

Error:

{
  "error": "Error message",
  "details": "Detailed error information"
}

Tech Stack

• Node.js 22
• Express.js 5.1.0
• Firebase Cloud Functions
• Firebase Cloud Messaging (FCM)