Messages can represent different kinds of incoming data. Most commonly,
messages are sent to the app after being initiated by the developer. Messages
are also sent to you app to represent message sent events, message send error
events, and messages deleted events. These special events can be differentiated
by checking the MessageType field.
Messages Deleted
Sent to your app when the FCM server deletes pending messages.
MessageType will be "deleted_messages". Messages may be deleted if:
Too many messages are stored on the FCM server.
This can occur when an app's servers send a bunch of non-collapsible
messages to FCM servers while the device is offline.
The device hasn't connected in a long time and the app server has
recently (within the last 4 weeks) sent a message to the app on that
device.
It is recommended that the app do a full sync with the app
server after receiving this call.
Send Event
Called when an upstream message has been successfully sent to FCM.
MessageType will be "send_event".
Send Error
Called when there was an error sending an upstream message.
MessageType will be "send_error".
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-09-04 UTC."],[],[],null,["Receive and handle messages\n\nTo receive messages, your app must assign a callback to the\n[Firebase.Messaging.FirebaseMessaging.MessageReceived](/docs/reference/unity/class/firebase/messaging/firebase-messaging#messagereceived)\nevent handler.\n\n`MessageReceived` Event\n\nBy overriding assigning a callback to\n[Firebase.Messaging.FirebaseMessaging.MessageReceived](/docs/reference/unity/class/firebase/messaging/firebase-messaging#messagereceived)\nyou can perform actions based on the received message and get the message data: \n\n```c#\npublic void OnMessageReceived(object sender, Firebase.Messaging.MessageReceivedEventArgs e) {\n UnityEngine.Debug.Log(\"From: \" + e.Message.From);\n UnityEngine.Debug.Log(\"Message ID: \" + e.Message.MessageId);\n}\n```\n\nMessages can represent different kinds of incoming data. Most commonly,\nmessages are sent to the app after being initiated by the developer. Messages\nare also sent to you app to represent message sent events, message send error\nevents, and messages deleted events. These special events can be differentiated\nby checking the `MessageType` field.\n\nMessages Deleted\n\nSent to your app when the FCM server deletes pending messages.\n`MessageType` will be `\"deleted_messages\"`. Messages may be deleted if:\n\n1. Too many messages are stored on the FCM server.\n\n This can occur when an app's servers send a bunch of non-collapsible\n messages to FCM servers while the device is offline.\n2. The device hasn't connected in a long time and the app server has\n recently (within the last 4 weeks) sent a message to the app on that\n device.\n\n It is recommended that the app do a full sync with the app\n server after receiving this call.\n\nSend Event\n\nCalled when an upstream message has been successfully sent to FCM.\n`MessageType` will be `\"send_event\"`.\n\nSend Error\n\nCalled when there was an error sending an upstream message.\n`MessageType` will be `\"send_error\"`."]]
