--- title: Sending notifications between Android devices with... description: A walkthrough of building cross-device notifications for an Android chat app using Firebase Realtime Database as a queue and Firebase Cloud Messaging (FCM) to... canonical: https://daily.dev/posts/sending-notifications-between-android-devices-with-firebase-database-and-cloud-messaging-geqfhrayb twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Sending notifications between Android devices with Firebase Database and Cloud Messaging | daily.dev og:description: A walkthrough of building cross-device notifications for an Android chat app using Firebase Realtime Database as a queue and Firebase Cloud Messaging (FCM) to... og:url: https://daily.dev/posts/sending-notifications-between-android-devices-with-firebase-database-and-cloud-messaging-geqfhrayb og:image: https://api.daily.dev/og/posts/GEQFhrayB.png og:image:alt: Sending notifications between Android devices with Firebase Database and Cloud Messaging og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Sending notifications between Android devices with Firebase Database and Cloud Messaging **[Firebase](https://daily.dev/sources/firebase-blog)** · 7 min read · 0 upvotes · 0 comments ## Summary A walkthrough of building cross-device notifications for an Android chat app using Firebase Realtime Database as a queue and Firebase Cloud Messaging (FCM) to deliver alerts. The Android app writes a notification request to the database; a trusted Node.js server listens for new entries and calls the FCM REST API to send push notifications via topic-based messaging (e.g. /topics/user_puf). The Android client subscribes to its username topic with a single line of code to receive messages. A note at the top mentions Cloud Functions for Firebase later offered a way to do this without running a Node.js server. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### How do I send a push notification from one Android device to another using Firebase? Write a notification request (username and message) into a Firebase Realtime Database node such as notificationRequests, then have a trusted Node.js server listen for child_added events on that node and call the Firebase Cloud Messaging REST API to deliver it. This avoids exposing the FCM server API key on the Android device itself. _daily.dev surfaces implementation patterns like this for developers wiring up Firebase-based notification systems._ ### How do I target a specific user with Firebase Cloud Messaging instead of broadcasting to all devices? Map each username to its own FCM topic, such as /topics/user_puf, and have that user's Android app subscribe to the topic via FirebaseMessaging.getInstance().subscribeToTopic("user_"+username). The server then sends the notification to that specific topic, so only the matching user's device receives it. _Developers designing per-user messaging flows can find similar Firebase patterns on daily.dev._ ## Similar posts on daily.dev - [When Notifications Became Data Trucks: A Real-World Crash Story from Firebase FCM](https://daily.dev/posts/when-notifications-became-data-trucks-a-real-world-crash-story-from-firebase-fcm-nh9ixqylv) · ProAndroidDev · 1 upvotes · 0 comments - [Deep Linking and Navigation from Notifications](https://daily.dev/posts/deep-linking-and-navigation-from-notifications-zyqz11wln) · Medium · 0 upvotes · 0 comments --- Tags: [#android](https://daily.dev/tags/android), [#nodejs](https://daily.dev/tags/nodejs), [#firebase](https://daily.dev/tags/firebase) [View this post on daily.dev](https://daily.dev/posts/sending-notifications-between-android-devices-with-firebase-database-and-cloud-messaging-geqfhrayb) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Sending notifications between Android devices with Firebase Database and Cloud Messaging","url":"https://daily.dev/posts/sending-notifications-between-android-devices-with-firebase-database-and-cloud-messaging-geqfhrayb","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/sending-notifications-between-android-devices-with-firebase-database-and-cloud-messaging-geqfhrayb"},"datePublished":"2026-08-23T12:20:52.376Z","dateModified":"2026-08-23T12:57:50.400Z","description":"A walkthrough of building cross-device notifications for an Android chat app using Firebase Realtime Database as a queue and Firebase Cloud Messaging (FCM) to...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/7ed721de96163685d26ab7e314be3ebc?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/7ed721de96163685d26ab7e314be3ebc?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"Firebase","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"Firebase","logo":"https://media.daily.dev/image/upload/s--i395oqZH--/f_auto,q_auto/v1787487448/logos/firebase-blog?_a=BAMAMicg0","url":"https://daily.dev/sources/firebase-blog"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/sending-notifications-between-android-devices-with-firebase-database-and-cloud-messaging-geqfhrayb","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":0},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"android,nodejs,firebase","timeRequired":"PT7M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"Firebase","item":"https://daily.dev/sources/firebase-blog"},{"@type":"ListItem","position":3,"name":"Sending notifications between Android devices with Firebase Database and Cloud Messaging"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/sending-notifications-between-android-devices-with-firebase-database-and-cloud-messaging-geqfhrayb#faq","mainEntity":[{"@type":"Question","name":"How do I send a push notification from one Android device to another using Firebase?","acceptedAnswer":{"@type":"Answer","text":"Write a notification request (username and message) into a Firebase Realtime Database node such as notificationRequests, then have a trusted Node.js server listen for child_added events on that node and call the Firebase Cloud Messaging REST API to deliver it. 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