Firebase Cloud Messaging

MARS Engine has a very straightforward way to send Push notifications to Android/iOS devices.

You would need an application registered on Firebase beforehand. If you are not familiar with it, you can look up the process here:
Firebase Cloud Messaging Documentation

Setup

Once you obtain the unique device key from your app, you can send it to your MARS backend and use it to direct messages.

To send a FCM Push Notification, simply invoke the FCM() module in MARS and pass your App Key (Server Key from Firebase dashboard).

Example

const fcmMsg = FCM("FCM Key for your App");
fcmMsg.to("DEVICE_KEY:AsdAf9g1bGtxmujyJVAV00jNoPxFuwFdcXux5rZrvmenthqdfJGnN38GD-8cfx52iBG_L5HahmxCXjpb0gLhkQ2O1YT8JXQ23c8sZh46fC3B1RZKOEECSpbJIJapGzl");

fcmMsg.title("Hey, something new happened!");
fcmMsg.body("A cat has just had fifteen kittens! Click this notification for a very cute video.");

fcmMsg.send();

✅ That’s it! A push notification will be sent to the device.

⚙️ Methods

Method	Parameters	Description
to()	Device ID or array of IDs	Specify recipients (up to 1000 per message, per Google’s limits)
title()	String	Heading text of the notification
sound()	"default" or custom sound	Plays a sound when the notification is received
body()	String	Subtext or message body
color()	Hex string (e.g. #fefefe)	Sets background icon color
data()	Map of key-value pairs	Hidden payload used by your app for internal behavior
send()	–	Sends the message to recipients

Notes

• Use .send() last to trigger delivery.
• Multiple recipients can be defined via array in .to().
• Any unconfigured optional fields will be omitted from the payload.