[Home](./index.md) > [@firebase/messaging](./messaging.md) > [MessagePayload](./messaging.messagepayload.md) ## MessagePayload interface Message payload that contains the notification payload that is represented with [NotificationPayload](./messaging.notificationpayload.md) and the data payload that contains an arbitrary number of key-value pairs sent by developers through the [Send API](https://firebase.google.com/docs/reference/fcm/rest/v1/projects.messages#notification) Signature: ```typescript export interface MessagePayload ``` ## Properties | Property | Type | Description | | --- | --- | --- | | [collapseKey](./messaging.messagepayload.collapsekey.md) | string | The collapse key of the message. See [Non-collapsible and collapsible messages](https://firebase.google.com/docs/cloud-messaging/concept-options#collapsible_and_non-collapsible_messages) | | [data?](./messaging.messagepayload.data.md) | { \[key: string\]: string; } | (Optional) Arbitrary key/value payload. | | [fcmOptions?](./messaging.messagepayload.fcmoptions.md) | [FcmOptions](./messaging.fcmoptions.md) | (Optional) Options for features provided by the FCM SDK for Web. See [WebpushFcmOptions](https://firebase.google.com/docs/reference/fcm/rest/v1/projects.messages#webpushfcmoptions) | | [from](./messaging.messagepayload.from.md) | string | The sender of this message. | | [notification?](./messaging.messagepayload.notification.md) | [NotificationPayload](./messaging.notificationpayload.md) | (Optional) Display notification details. They are sent through the [Send API](https://firebase.google.com/docs/reference/fcm/rest/v1/projects.messages#notification) |