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tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/android/setup" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/web/setup" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Web</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Add Firebase to a game</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/games/setup" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cpp/setup" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>C++</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/unity/setup" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Unity</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/admin/setup" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Add Firebase to a server</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Use Firebase with a framework</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/flutter/setup" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Flutter</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/api/workflow_set-up-and-manage-project" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set up projects programmatically</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Manage your Firebase projects</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/learn-more" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Understand Firebase projects</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/locations" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Select locations for your project</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/multiprojects" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Configure multiple projects</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/pwa" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use Firebase in PWAs</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/bigquery-export" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Export project data to BigQuery</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/manage-installations" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Firebase installations</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Manage projects programmatically</span></div></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/api/workflow_set-up-and-manage-project" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use the REST API</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Use the Admin SDK</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/admin/node/admin.projectManagement" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Node.js</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/admin/java/reference/com/google/firebase/projectmanagement/package-summary" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Java</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/admin/python/firebase_admin.project_management" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Python</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/provisioning/configure-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Configure OAuth identity providers for Firebase Auth</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Manage project access (IAM)</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/iam/overview" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Roles</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/iam/roles" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/iam/roles-primitive" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Owner, Editor, Viewer roles</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Firebase predefined roles</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/iam/roles-predefined" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/iam/roles-predefined-all-products" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Firebase-level roles</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/iam/roles-predefined-category" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Product-category roles</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/iam/roles-predefined-product" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Product-level roles</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/iam/roles-custom" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Custom roles</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/projects/iam/permissions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Permissions</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion devsite-nav-beta"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Prototype and test with Emulator Suite</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/emulator-suite" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Connect your app and prototype</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/emulator-suite/connect_and_prototype" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/emulator-suite/connect_rtdb" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Connect to the Realtime Database emulator</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/emulator-suite/connect_firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Connect to the Cloud Firestore emulator</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/emulator-suite/connect_functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Connect to the Cloud Functions emulator</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/emulator-suite/install_and_configure" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Install, configure and integrate</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Analytics</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Log Events</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/user-properties" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set User Properties</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/debugview" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Debug Events</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/screenviews" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Track Screens</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/userid" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set a User ID</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/measure-ecommerce" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Measure Ecommerce</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/webview" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use in a WebView</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/extend-with-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Extend with Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/configure-data-collection" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Configure Data Collection and Usage</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Error Codes</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>C++</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/cpp/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/cpp/events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Log Events</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/cpp/properties" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set User Properties</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Unity</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/unity/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/unity/events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Log Events</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/analytics/unity/properties" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set User Properties</span></a></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion devsite-nav-beta"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Extensions</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/extensions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Use an extension in your project</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/extensions/overview-use-extensions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/extensions/install-extensions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Install an extension</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/extensions/manage-installed-extensions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage installed extensions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/extensions/permissions-granted-to-extension" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Permissions granted to an extension</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-divider devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Develop</span></div></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Authentication</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/where-to-start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Where do I start?</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Users in Firebase Projects</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>iOS</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/firebaseui" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with a pre-built UI</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/manage-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Users</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/password-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Password Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/email-link-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Email Link Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/google-signin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Google Sign-In</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/facebook-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Facebook Login</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/apple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with Apple</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/twitter-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Twitter Login</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/github-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>GitHub</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/microsoft-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Microsoft</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/yahoo-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Yahoo</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/game-center" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Game Center Sign-in</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/phone-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Phone Number</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/custom-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use a Custom Auth System</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/anonymous-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Anonymous Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/single-sign-on" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Enabling cross-app authentication with shared iOS Keychain</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/account-linking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Link Multiple Auth Providers</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/passing-state-in-email-actions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Passing State in Email Actions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/ios/errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handle Errors</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Android</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/firebaseui" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with a pre-built UI</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started with the Firebase SDK</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/manage-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Users</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/password-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Password Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/email-link-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Email Link Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/google-signin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Google Sign-In</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/facebook-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Facebook Login</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/apple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with Apple</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/twitter-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Twitter</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/github-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>GitHub</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/microsoft-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Microsoft</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/yahoo-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Yahoo</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/play-games" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Play Games Sign-in</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/phone-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Phone Number</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/custom-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use a Custom Auth System</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/anonymous-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Anonymous Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/account-linking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Link Multiple Auth Providers</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/android/passing-state-in-email-actions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Passing State in Email Actions</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Web</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/firebaseui" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with a pre-built UI</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/manage-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Users</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/password-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Password Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/email-link-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Email Link Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/google-signin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Google Sign-In</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/facebook-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Facebook Login</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/apple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with Apple</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/twitter-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Twitter</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/github-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>GitHub</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/microsoft-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Microsoft</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/yahoo-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Yahoo</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/phone-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Phone Number</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/custom-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use a Custom Auth System</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/anonymous-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Anonymous Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/account-linking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Link Multiple Auth Providers</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/cordova" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>OAuth Sign-In for Cordova</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/auth-state-persistence" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Auth State Persistence</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/passing-state-in-email-actions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Passing State in Email Actions</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/web/service-worker-sessions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Service Worker Sessions</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>C++</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/manage-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Users</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/password-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Password Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/google-signin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Google Sign-in</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/play-games" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Play Games Sign-in</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/github-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>GitHub</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/facebook-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Facebook Login</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/apple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with Apple</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/twitter-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Twitter Login</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/microsoft-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Microsoft</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/yahoo-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Yahoo</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/phone-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Phone Number</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/custom-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use a Custom Auth System</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/anonymous-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Anonymous Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/cpp/account-linking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Link Multiple Auth Providers</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Unity</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/manage-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Users</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/password-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Password Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/google-signin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Google Sign-in</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/play-games" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Play Games Sign-in</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/github-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>GitHub Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/facebook-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Facebook Login</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/apple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sign in with Apple</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/twitter-login" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Twitter Login</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/microsoft-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Microsoft</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/yahoo-oauth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Yahoo</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/phone-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Phone Number</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/custom-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use a Custom Auth System</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/anonymous-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Anonymous Authentication</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/unity/account-linking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Link Multiple Auth Providers</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Admin</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/admin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/admin/manage-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Users</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/admin/import-users" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Import Users</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/admin/create-custom-tokens" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create Custom Tokens</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/admin/verify-id-tokens" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Verify ID Tokens</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/admin/manage-sessions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage User Sessions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/admin/manage-cookies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Session Cookies</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/admin/custom-claims" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Control Access with Custom Claims</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/admin/email-action-links" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Generating Email Action Links</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/admin/errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Errors</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/admin/migrate-admin" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Migration Guide</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/custom-email-handler" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Customize the Email Action Handler</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/extend-with-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Extend with Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/case-studies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Case Studies</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/auth/limits" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Usage Limits</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Realtime Database</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/rtdb-vs-firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Choose a Database</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>iOS</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/ios/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/ios/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/ios/read-and-write" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Read and Write Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/ios/lists-of-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Work with Lists of Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/ios/offline-capabilities" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Enable Offline Capabilities</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Android</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/android/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/android/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/android/read-and-write" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Read and Write Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/android/lists-of-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Work with Lists of Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/android/offline-capabilities" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Enable Offline Capabilities</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Web</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/web/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/web/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/web/read-and-write" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Read and Write Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/web/lists-of-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Work with Lists of Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/web/offline-capabilities" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Enable Offline Capabilities</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Admin</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/admin/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/admin/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/admin/save-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Save Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/admin/retrieve-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Retrieve Data</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>REST</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/rest/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/rest/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/rest/save-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Save Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/rest/retrieve-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Retrieve Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/rest/auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Authenticate REST Requests</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>C++</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/cpp/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/cpp/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/cpp/save-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Save Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/cpp/retrieve-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Retrieve Data</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Unity</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/unity/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/unity/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/unity/save-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Save Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/unity/retrieve-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Retrieve Data</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Security & Rules</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/security" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Understand Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/security/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/security/core-syntax" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Security Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/security/rules-conditions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Write Conditions for Security Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/security/indexing-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Index Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/rest/app-management" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Rules via REST</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Usage and Performance</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/usage/billing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Understand Billing</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/usage/limits" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Realtime Database Limits</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/usage/monitor-usage" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Monitor Database Usage</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/usage/monitor-performance" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Monitor Database Performance</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/usage/sharding" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Scale with Multiple Databases</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/usage/profile" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Profile Your Database</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/usage/optimize" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Optimize Database Performance</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/backups" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Automated Backups</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/extend-with-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Extend with Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/database/video-series" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Video series: Firebase for SQL Developers</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Cloud Firestore</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/quickstart" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Understand Cloud Firestore</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/rtdb-vs-firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Compare Cloud Firestore and Realtime Database</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/data-model" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Data model</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/manage-data/data-types" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Data types</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/client/libraries" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>SDKs and client libraries</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/query-data/index-overview" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Index types</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/locations" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Database locations</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Add and manage data</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/manage-data/structure-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/manage-data/add-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Add data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/manage-data/transactions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Transactions and batched writes</span></a></li><li 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href="/web/20201004011617/https://firebase.google.com/docs/firestore/manage-data/move-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Move data between projects</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Read data</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/query-data/get-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get data once</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/query-data/listen" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Listen for realtime updates</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/query-data/queries" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Perform simple and compound queries</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/query-data/order-limit-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Order and limit data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/query-data/query-cursors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Paginate data with query cursors</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/manage-data/enable-offline" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Access data offline</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/query-data/indexing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage indexes</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Secure and validate data</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/security/overview" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/security/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/security/rules-structure" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Security Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/security/rules-conditions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Writing conditions for Security Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/security/insecure-rules" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Fix insecure rules</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/security/test-rules-emulator" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test your Security Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/security/rules-query" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Securely query data</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Solutions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/solutions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/solutions/aggregation" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Aggregation Queries</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/solutions/counters" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Distributed counters</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/solutions/search" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Full-text search</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/solutions/presence" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Build presence</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/solutions/role-based-access" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Secure data access for users and groups</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/solutions/delete-collections" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete data with a callable Cloud Function</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/solutions/schedule-export" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Schedule data exports</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/solutions/shard-timestamp" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sharded timestamps</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/solutions/automate-database-create" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Automating database creation</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/solutions/index-map-field" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Reduce index costs with map fields</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Usage, limits, and pricing</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/quotas" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Usage and limits</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/monitor-usage" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Monitor usage</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/pricing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Understand Cloud Firestore billing</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/billing-example" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Example Cloud Firestore costs</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/storage-size" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Understand storage size calculations</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/best-practices" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Best practices for Cloud Firestore</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Cloud Firestore integrations</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/use-rest-api" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use the Cloud Firestore REST API</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/firestore-for-rtdb" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use Cloud Firestore and Realtime Database</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/extend-with-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Extend with Cloud Functions</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/library-integrations" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Third-party library integrations</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>API reference</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/android/com/google/firebase/firestore/package-summary" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/swift/firebasefirestore/api/reference/Classes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS — Swift</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/ios/firebasefirestore/api/reference/Classes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS — Objective-C</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/js/firebase.firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Web</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/functions/providers_firestore_" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="//web.archive.org/web/20201004011617/https://googleapis.dev/nodejs/firestore/latest/" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Node.js</span></a></li><li class="devsite-nav-item"><a href="//web.archive.org/web/20201004011617/https://googleapis.github.io/google-cloud-java/google-cloud-clients/apidocs/index.html?com/google/cloud/firestore/package-summary.html" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Java</span></a></li><li class="devsite-nav-item"><a href="//web.archive.org/web/20201004011617/https://googleapis.github.io/google-cloud-python/latest/firestore/client.html" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Python</span></a></li><li class="devsite-nav-item"><a href="//web.archive.org/web/20201004011617/https://godoc.org/cloud.google.com/go/firestore" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Go</span></a></li><li class="devsite-nav-item"><a href="//web.archive.org/web/20201004011617/https://googleapis.github.io/google-cloud-dotnet/docs/Google.Cloud.Firestore/" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>C#</span></a></li><li class="devsite-nav-item"><a href="//web.archive.org/web/20201004011617/https://googleapis.github.io/google-cloud-php/#/docs/cloud-firestore/latest/firestore/readme" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>PHP</span></a></li><li class="devsite-nav-item"><a href="//web.archive.org/web/20201004011617/https://googleapis.github.io/google-cloud-ruby/docs/google-cloud-firestore/latest/Google/Firestore/V1beta1" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Ruby</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/reference/rest" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>REST</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/reference/rpc" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>RPC</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Samples</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/client/samples-ios" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/client/samples-android" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/firestore/client/samples-web" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Web</span></a></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Storage</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>iOS</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/ios/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/ios/create-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create a Reference</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/ios/upload-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upload Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/ios/download-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Download Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/ios/file-metadata" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use File Metadata</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/ios/delete-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/ios/list-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>List Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/ios/handle-errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handle Errors</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Android</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/android/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/android/create-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create a Reference</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/android/upload-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upload Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/android/download-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Download Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/android/file-metadata" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use File Metadata</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/android/delete-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/android/list-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>List Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/android/handle-errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handle Errors</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Web</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/web/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/web/create-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create a Reference</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/web/upload-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upload Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/web/download-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Download Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/web/file-metadata" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use File Metadata</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/web/delete-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/web/list-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>List Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/web/handle-errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handle Errors</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Admin</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/admin/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>C++</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/cpp/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/cpp/create-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create a Reference</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/cpp/upload-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upload Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/cpp/download-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Download Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/cpp/file-metadata" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use File Metadata</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/cpp/delete-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/cpp/handle-errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handle Errors</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Unity</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/unity/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/unity/create-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create a Reference</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/unity/upload-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upload Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/unity/download-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Download Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/unity/file-metadata" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use File Metadata</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/unity/delete-files" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete Files</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/unity/handle-errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handle Errors</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Security & Rules</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/security" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Understand Security</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/security/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/security/core-syntax" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Structure Security Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/security/rules-conditions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Write Conditions for Security Rules</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/monitor-storage" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Monitor activity</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/extend-with-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Extend with Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/storage/gcp-integration" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Integrate with Google Cloud</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Hosting</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/use-cases" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>What can you do with Firebase Hosting?</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/quickstart" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/deploying" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test locally then deploy</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/multisites" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Share project resources across multiple sites</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/custom-domain" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Connect a custom domain</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/full-config" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Configure hosting behavior</span></a></li><li class="devsite-nav-item devsite-nav-new"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/i18n-rewrites" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Configure i18n rewrites</span><span class="devsite-nav-icon material-icons" data-icon="new" data-title="New!" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/reserved-urls" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Add SDKs using reserved URLs</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Serve dynamic content and host microservices</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/serverless-overview" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use Cloud Functions for Firebase</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/cloud-run" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use Cloud Run</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/manage-cache" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage cache behavior</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/manage-releases" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage releases</span></a></li><li class="devsite-nav-item devsite-nav-new"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/web-request-logs-and-metrics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Monitor web request data with Cloud Logging</span><span class="devsite-nav-icon material-icons" data-icon="new" data-title="New!" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-new"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/usage-quotas-pricing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Usage, quotas, and pricing</span><span class="devsite-nav-icon material-icons" data-icon="new" data-title="New!" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/hosting/api-deploy" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Deploy using the REST API</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Cloud Functions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/use-cases" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>What can I do with Cloud Functions?</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/beta-v1-diff" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upgrade to v1.0+ from beta</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Call functions directly</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/callable" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Call functions from your app</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/http-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Call functions via HTTP requests</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/schedule-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Run functions on a schedule</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Trigger background functions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/firestore-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cloud Firestore triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/database-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Realtime Database triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/rc-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Remote Config triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/auth-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Authentication triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/analytics-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Analytics triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-deprecated"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/crashlytics-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Crashlytics triggers</span><span class="devsite-nav-icon material-icons" data-icon="deprecated" data-title="Deprecated" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/gcp-storage-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cloud Storage triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/pubsub-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cloud Pub/Sub triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/test-lab-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test Lab triggers</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Write functions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/manage-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage deployment and runtime options</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/typescript" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Write functions in TypeScript</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/terminate-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Sync, async, and promises</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/retries" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Retry asynchronous functions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/config-env" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Environment configuration</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/organize-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Organize functions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/handle-dependencies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Handling dependencies</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/networking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Optimizing networking</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/tips" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Tips & tricks</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Test functions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/local-emulator" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Run functions locally</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/unit-testing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Unit testing functions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/local-shell" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test functions interactively</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Monitor functions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/writing-and-viewing-logs" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Write and view logs</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/reporting-errors" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Report errors</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/monitored-metrics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>View monitored metrics</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>API Reference</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Firebase SDK for Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/functions/test" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test SDK</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/callable-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Protocol specification for https.onCall</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/video-series" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Video Series: learn Cloud Functions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/functions-and-firebase" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cloud Functions and Firebase</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/locations" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cloud Functions locations</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/functions/quotas" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Quotas and limits</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion devsite-nav-beta"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Machine Learning</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Vision</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Recognize text</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/recognize-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/ios/recognize-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/android/recognize-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Label images</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/label-images" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/ios/label-images" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/android/label-images" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Recognize landmarks</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/recognize-landmarks" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/ios/recognize-landmarks" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/android/recognize-landmarks" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>AutoML Vision Edge</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/automl-image-labeling" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/train-image-labeler" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Train image labeling models</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Label images with your models</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/ios/label-images-with-automl" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/android/label-images-with-automl" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/migrate-automl-datasets" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Migrate datasets</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Custom Models</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Use a custom model</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/use-custom-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/ios/use-custom-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/android/use-custom-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/manage-hosted-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Deploy & manage custom models</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Migrate from the legacy API</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/ios/migrate-from-legacy-api" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/android/migrate-from-legacy-api" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Advanced Topics</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>A/B test two versions of a model</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/ios/ab-test-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/android/ab-test-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Prepare for Production</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Protect your Cloud credentials</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/ios/secure-api-key" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml/android/secure-api-key" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Legacy Documentation</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>ML Kit for Firebase</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Vision</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Recognize text</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/recognize-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/recognize-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/recognize-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Detect faces</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/detect-faces" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/face-detection-concepts" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Concepts</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/detect-faces" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/detect-faces" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Scan barcodes</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/read-barcodes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/read-barcodes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/read-barcodes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Label images</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/label-images" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/label-images" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/label-images" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Detect and track objects</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/object-detection" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/detect-objects" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/detect-objects" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Recognize landmarks</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/recognize-landmarks" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/recognize-landmarks" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/recognize-landmarks" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>AutoML Vision Edge</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/automl-image-labeling" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/train-image-labeler" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Train image labeling models</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Label images with your models</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/label-images-with-automl" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/label-images-with-automl" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/migrate-automl-datasets" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Migrate datasets</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Natural Language</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Identify the language of text</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/identify-languages" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/identify-languages" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/identify-languages" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Translate text</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/translation" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/translate-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/translate-text" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/translation-terms" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Usage guidelines</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Generate smart replies</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/generate-smart-replies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/generate-smart-replies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/generate-smart-replies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Custom Models</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Use a custom model</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/use-custom-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/use-custom-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/use-custom-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/manage-hosted-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage hosted custom models</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Use a custom TensorFlow Lite build</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/use-custom-tflite" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/use-custom-tflite" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Advanced Topics</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>A/B test two versions of a model</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/ab-test-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/ab-test-models" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Prepare for Production</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Reduce app package size</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/reduce-app-size" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Protect your Cloud credentials</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/ios/secure-api-key" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ml-kit/android/secure-api-key" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Security Rules</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Understand Security Rules</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules/rules-language" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Security Rules language</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules/rules-behavior" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>How Security Rules work</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules/rules-and-auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Security Rules and Firebase Authentication</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Write Security Rules</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules/basics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Basic Security Rules</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules/insecure-rules" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Avoid insecure rules</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules/data-validation" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Data validation</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Test Security Rules</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules/emulator-setup" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set up the emulator</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules/unit-tests" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Build unit tests</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules/emulator-reports" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Generate test reports</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules/simulator" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Quickly validate Security Rules</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/rules/manage-deploy" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage and deploy Security Rules</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-divider devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Quality</span></div></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Crashlytics</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/start-using-analytics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Start using Google Analytics</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/test-implementation" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test your implementation</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/customize-crash-reports" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Customize crash reports</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/get-deobfuscated-reports" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get deobfuscated crash reports</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/ndk-reports" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Android NDK crash reports</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/velocity-alerts" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Customize velocity alerts</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/bigquery-export" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Export data to BigQuery</span></a></li><li class="devsite-nav-item devsite-nav-deprecated"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/extend-with-cloud-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Extend with Cloud Functions</span><span class="devsite-nav-icon material-icons" data-icon="deprecated" data-title="Deprecated" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>From Fabric to Firebase</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/migration-post-linking" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Steps after migrating your app</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/upgrade-sdk" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Upgrade to the Firebase Crashlytics SDK</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/switch-to-analytics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Switch from Answers to Analytics</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Deprecated Fabric SDK guides</span></div></li><li class="devsite-nav-item devsite-nav-deprecated"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/customize-crash-reports-fabric-sdk" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Customize crash reports</span><span class="devsite-nav-icon material-icons" data-icon="deprecated" data-title="Deprecated" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-deprecated"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/force-a-crash" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test your implementation</span><span class="devsite-nav-icon material-icons" data-icon="deprecated" data-title="Deprecated" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-deprecated"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/get-deobfuscated-reports-fabric-sdk" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get deobfuscated crash reports</span><span class="devsite-nav-icon material-icons" data-icon="deprecated" data-title="Deprecated" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-deprecated"><a href="/web/20201004011617/https://firebase.google.com/docs/crashlytics/ndk-reports-fabric-sdk" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Android NDK crash reports</span><span class="devsite-nav-icon material-icons" data-icon="deprecated" data-title="Deprecated" aria-hidden="true"></span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Performance Monitoring</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Get started</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/get-started-ios" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/get-started-android" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/get-started-web" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Web</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Learn about automatically collected data</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/app-start-foreground-background-traces" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>App start, foreground, background (iOS & Android)</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/screen-traces" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Screen rendering (iOS & Android)</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/page-load-traces" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Page loading (web)</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/network-traces" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>HTTP/S network requests</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Customize data collection and aggregation</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/custom-code-traces" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Add monitoring for specific code</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/custom-network-traces" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Add monitoring for specific network requests</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/custom-url-patterns" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create custom URL patterns</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/disable-sdk" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Disable Performance Monitoring</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Track, view, and filter data</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview of the console</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/attributes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Filter data using attributes</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/issue-management" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>View performance issues</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/bigquery-export" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Export data to BigQuery</span></a></li><li class="devsite-nav-item devsite-nav-break"></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/perf-mon/troubleshooting" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Troubleshooting</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Test Lab</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>iOS</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/ios/firebase-console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test with the Firebase console</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/ios/command-line" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test with the gcloud CLI</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/game-loop" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Run a Game Loop test</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/ios/analyzing-results" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Analyze test results</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/ios/available-testing-devices" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test on available devices</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Android</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/android/overview" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/android/firebase-console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test with the Firebase console</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/android/command-line" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test with the gcloud CLI</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/android/continuous" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test with CI systems</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/android/android-studio" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test with Android Studio</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/android/analyzing-results" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Analyze test results</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/android/available-testing-devices" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test on available devices</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/android/instrumentation-test" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Run an instrumentation test</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/android/robo-ux-test" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Run a Robo test</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/android/game-loop" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Run a Game Loop test</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/android/test-screenshots" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Take screenshots in a test</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/android/avds" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test with virtual devices</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-new"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/troubleshooting" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Troubleshooting</span><span class="devsite-nav-icon material-icons" data-icon="new" data-title="New!" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/extend-with-functions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Extend with Cloud Functions</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>REST API reference</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/reference/testing/rest" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Testing (submit test & monitor)</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/test-lab/reference/toolresults/rest" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>ToolResults (retrieve results)</span></a></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion devsite-nav-beta"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>App Distribution</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution/manage-testers" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage testers</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution/troubleshooting" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Troubleshooting</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Set up for testers</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution/ios/set-up-for-testing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution/android/set-up-for-testing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Distribute iOS apps</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution/ios/distribute-console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use the Firebase console</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution/ios/distribute-cli" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use the Firebase CLI</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution/ios/distribute-fastlane" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use fastlane</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution/set-up-alerts" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set up in-app alerts</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Distribute Android apps</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution/android/distribute-console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use the Firebase console</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution/android/distribute-cli" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use the Firebase CLI</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution/android/distribute-fastlane" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use fastlane</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-distribution/android/distribute-gradle" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use Gradle</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-divider devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Grow</span></div></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Predictions</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/predictions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/predictions/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/predictions/predefined-predictions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Churn and spend predictions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/predictions/bigquery-export" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Export prediction data to BigQuery</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Use case examples</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/predictions/use-cases/prevent-churn" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Prevent churn</span></a></li><li class="devsite-nav-item devsite-nav-break"></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Legacy Predictions (deprecated)</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/predictions/v1" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/predictions/v1/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Use Cases</span></div></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/predictions/use-cases/prevent-churn" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Prevent Churn</span></a></li><li class="devsite-nav-item devsite-nav-break"></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/predictions/v1/explore-predictions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Explore Prediction Results</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/predictions/v1/bigquery-export" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Export Prediction Data to BigQuery</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/predictions/v1/predefined-predictions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Churn and Spend Predictions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/predictions/v1/risk-profiles" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Risk Tolerance and Model Performance</span></a></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion devsite-nav-beta"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>A/B Testing</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ab-testing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ab-testing/abtest-config" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create Remote Config Experiments with A/B Testing</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ab-testing/abtest-with-console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create Messaging Experiments with A/B Testing</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ab-testing/abtest-inappmessaging" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Create In-App Messaging Experiments with A/B Testing</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ab-testing/video-series" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Video Series: Learn A/B Testing</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Cloud Messaging</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/fcm-architecture" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>FCM Architectural Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/concept-options" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>About FCM messages</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>iOS</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/ios/client" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set up an iOS client</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/ios/certs" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Configuring APNs with FCM</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/ios/first-message" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send a test message</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/ios/send-multiple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages to multiple devices</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/ios/send-image" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send an image in the notification payload</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/ios/receive" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Receive messages</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/ios/topic-messaging" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages to topics</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/ios/device-group" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send to device groups</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/ios/send-with-console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages with the Firebase Console</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Android</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/android/client" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set up an Android client</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/android/first-message" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send a test message</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/android/send-multiple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages to multiple devices</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/android/send-image" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send an image in the notification payload</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/android/receive" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Receive messages</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/android/topic-messaging" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages to topics</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/android/device-group" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send to device groups</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/android/upstream" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send upstream messages</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/android/send-with-console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages with the Firebase Console</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>C++</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/cpp/client" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set up a C++ client</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/cpp/receive" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Receive messages</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/cpp/topic-messaging" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages to topics</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/cpp/device-group" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send to device groups</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/cpp/upstream" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send upstream messages</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/cpp/send-with-console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages with the Firebase Console</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Unity</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/unity/client" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set up a Unity client</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/unity/receive" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Receive messages</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/unity/topic-messaging" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages to topics</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/unity/device-group" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send to device groups</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/unity/upstream" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send upstream messages</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/unity/send-with-console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages with the Firebase Console</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Web (JavaScript)</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/js/client" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Set up a JavaScript client</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/js/first-message" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send a test message</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/js/send-multiple" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages to multiple devices</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/js/receive" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Receive messages</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/js/topic-messaging" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages to topics</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/js/device-group" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send to device groups</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/js/send-with-console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Send messages with the Firebase Console</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/js/case-studies" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Case studies</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Server environments</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/server" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Your server environment and FCM</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/migrate-v1" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Migrate to the HTTP v1 API</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/auth-server" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Authorize send requests</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/send-message" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Build send requests</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/receive-upstream" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Receive upstream messages</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/manage-topics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage topics from the server</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/cloud-messaging/understand-delivery" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Understanding message delivery</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion devsite-nav-beta"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>In-App Messaging</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/in-app-messaging" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/in-app-messaging/get-started" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/in-app-messaging/explore-use-cases" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Explore use cases</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/in-app-messaging/compose-campaign" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Compose a campaign</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/in-app-messaging/modify-message-behavior" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Modify message behavior</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/in-app-messaging/customize-messages" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Customize messages</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Remote Config</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>What can I do with Remote Config?</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/use-cases" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Remote Config use cases</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Key concepts and strategies</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/parameters" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Parameters and conditions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/templates" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Templates and versioning</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/loading" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Config loading strategies</span></a></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/propagate-updates-realtime" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Propagate updates in real time</span><span class="devsite-nav-icon material-icons" data-icon="beta" data-title="Beta" aria-hidden="true"></span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/config-analytics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Remote Config and Analytics</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>iOS</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/use-config-ios" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started with Remote Config on iOS</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Android</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/use-config-android" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started with Remote Config on Android</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Web (JavaScript)</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/use-config-web" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started with Remote Config on Web</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>C++</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/use-config-cpp" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use Remote Config with C++</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Unity</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/use-config-unity" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use Remote Config with Unity</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/automate-rc" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Modify Remote Config programmatically</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>API reference</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/remote-config/rest" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>REST API reference</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/remote-config/condition-reference" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Conditional expression reference</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/android/com/google/firebase/remoteconfig/package-summary" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android SDK reference</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/swift/firebaseremoteconfig/api/reference/Classes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS Swift SDK reference</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/ios/firebasecore/api/reference/Classes" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS Obj-C SDK reference</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/unity/namespace/firebase/remote-config" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Unity reference</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/reference/cpp/namespace/firebase/remote-config" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>C++ reference</span></a></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Dynamic Links</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Use Cases</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/use-cases" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Overview</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/use-cases/web-to-app" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Convert Web Users To App Users</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/use-cases/user-to-user" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Invite Users to Your App</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/use-cases/rewarded-referral" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Reward User Referrals</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/operating-system-integrations" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Operating System Integrations</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Create Dynamic Links</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/create-links" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/ios/create" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/android/create" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/cpp/create" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>C++</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/unity/create" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Unity</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/rest" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>REST</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/create-manually" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manual URL Construction</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Receive Dynamic Links</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/ios/receive" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/android/receive" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Android</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/cpp/receive" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>C++</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/unity/receive" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Unity</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/custom-domains" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use a Custom Domain</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/analytics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>View Analytics Data</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/debug" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Debug Dynamic Links</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/dynamic-links/link-previews" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Link Previews & Social Metadata</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Google AdMob</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/admob" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/admob/ios/quick-start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started for iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/admob/android/quick-start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started for Android</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/admob/analytics-and-firebase" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Use Analytics and Firebase with AdMob apps</span></a></li><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>Use AdMob in a game</span></div></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>C++</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/admob/cpp/quick-start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/admob/cpp/cocos2d-x" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Cocos2d-x</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/admob/cpp/rewarded-video" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Rewarded video</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Unity</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item devsite-nav-external"><a href="//web.archive.org/web/20201004011617/https://developers.google.com/admob/unity/start" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get started</span><span class="devsite-nav-icon material-icons" data-icon="external" data-title="External" aria-hidden="true"></span></a></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Google Ads</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/ads" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li></ul></devsite-expandable-nav></li> <li class="devsite-nav-item devsite-nav-expandable devsite-nav-accordion"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>App Indexing</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-indexing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Introduction</span></a></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>iOS</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-indexing/ios/app" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-indexing/ios/test" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test Your Implementation</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-indexing/ios/measure" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Enhance Search Performance</span></a></li></ul></devsite-expandable-nav></li><li class="devsite-nav-item devsite-nav-expandable"><devsite-expandable-nav collapsed> <a class="devsite-nav-toggle" aria-hidden="true"></a><div class="devsite-nav-title devsite-nav-title-no-path" tabindex="0" role="button"><span class="devsite-nav-text" tooltip>Android</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-indexing/android/app" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get Started</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-indexing/android/public-content" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Refine Public Content Indexing</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-indexing/android/log-actions" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Log User Actions</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-indexing/android/test" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test Your Implementation</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-indexing/android/measure" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Enhance Search Performance</span></a></li><li class="devsite-nav-item"><a href="/web/20201004011617/https://firebase.google.com/docs/app-indexing/android/migrate" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Migrate to the Latest API</span></a></li></ul></devsite-expandable-nav></li></ul></devsite-expandable-nav></li> </ul> </div> </div> </nav> </devsite-book-nav> <section id="gc-wrapper"> <main role="main" class="devsite-main-content" has-book-nav has-toc> <devsite-toc class="devsite-nav"></devsite-toc> <devsite-content> <article class="devsite-article"> <article class="devsite-article-inner"><style> /* Styles inlined from /styles/docs.css */ .center { text-align: center } /* Used in AdMob code examples */ .oldcode { opacity: .40; /* IE 8 */ -ms-filter: "progid:DXImageTransform.Microsoft.Alpha(Opacity=40)"; 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left; } .full-page-selector-dropdown:hover .kd-buttonbar { border: none; height: inherit; } .full-page-selector-dropdown h3:hover { color: white; background-color: #039be5; } .full-page-selector-dropdown:hover .devsite-overflow-menu-button { display: none; } </style> <div class="devsite-article-meta"> <ul class="devsite-breadcrumb-list" role="navigation" aria-label="Breadcrumb"> <li class="devsite-breadcrumb-item "> <a href="/web/20201004011617/https://firebase.google.com/" class="devsite-breadcrumb-link gc-analytics-event" data-category="Site-Wide Custom Events" data-label="Breadcrumbs" data-value="1"> Firebase </a> </li> <li class="devsite-breadcrumb-item "> <div class="devsite-breadcrumb-guillemet material-icons" aria-hidden="true"></div> <a href="/web/20201004011617/https://firebase.google.com/docs" class="devsite-breadcrumb-link gc-analytics-event" data-category="Site-Wide Custom Events" data-label="Breadcrumbs" data-value="2"> Docs </a> </li> <li class="devsite-breadcrumb-item "> <div class="devsite-breadcrumb-guillemet material-icons" aria-hidden="true"></div> <a href="/web/20201004011617/https://firebase.google.com/docs/database" class="devsite-breadcrumb-link gc-analytics-event" data-category="Site-Wide Custom Events" data-label="Breadcrumbs" data-value="3"> Firebase Realtime Database </a> </li> <li class="devsite-breadcrumb-item "> <div class="devsite-breadcrumb-guillemet material-icons" aria-hidden="true"></div> <a href="/web/20201004011617/https://firebase.google.com/docs/guides" class="devsite-breadcrumb-link gc-analytics-event" data-category="Site-Wide Custom Events" data-label="Breadcrumbs" data-value="4"> Guides </a> </li> </ul> <devsite-page-rating position="header" selected-rating="0" hover-rating-star="0"> </devsite-page-rating> </div> <devsite-feedback position="header" project-name="Firebase Realtime Database" product-id="719752" bucket="" context="" version="t-devsite-webserver-20200924-r01-rc00.429872899142986475" data-label="Send Feedback Button" track-type="feedback" track-name="sendFeedbackLink" track-metadata-position="header" project-feedback-url="https://firebase.google.com/support/contact/bugs-features/" project-icon="https://www.gstatic.com/devrel-devsite/prod/v85e39fe21f53c758adf6c791fb94a7a2182cff2705b3dc8ed7c59fc745471159/firebase/images/touchicon-180.png" project-support-url="https://firebase.google.com/support/"> <button> Send feedback </button> </devsite-feedback> <h1 class="devsite-page-title">Retrieving Data</h1> <devsite-toc class="devsite-nav" devsite-toc-embedded> </devsite-toc> <div class="devsite-article-body clearfix "> <p> This document covers the basics of retrieving database data, how data is ordered, and how to perform simple queries on data. Data retrieval in the Admin SDK is implemented slightly differently across different programming languages. </p> <ol> <li> <strong>Asynchronous listeners:</strong> Data stored in a Firebase Realtime Database is retrieved by attaching an asynchronous listener to a database reference. The listener is triggered once for the initial state of the data and again anytime the data changes. An event listener may receive several different <a href="#section-event-types">types of events</a>. This mode of data retrieval is supported in Java, Node.js and Python Admin SDKs. </li> <li> <strong>Blocking reads:</strong> Data stored in a Firebase Realtime Database is retrieved by invoking a blocking method on a database reference, which returns the data stored at the reference. Each method call is a onetime operation. That means the SDK does not register any callbacks that listen to subsequent data updates. This model of data retrieval is supported in Python and Go Admin SDKs. </li> </ol> <aside class="note"> <p>The Go Admin SDK currently only supports blocking reads. It cannot be used to add event listeners that receive realtime update notifications. </p> </aside>  <h2 id="section-start" data-text="Getting Started" tabindex="0">Getting Started</h2> <p> Let's revisit the blogging example from the previous article to understand how to read data from a Firebase database. Recall that the blog posts in the example app are stored at the database URL <a href="https://web.archive.org/web/20201004011617/https://docs-examples.firebaseio.com/server/saving-data/fireblog/posts">https://docs-examples.firebaseio.com/server/saving-data/fireblog/posts.json</a>. To read your post data, you can do the following: </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> public static class Post { public String author; public String title; public Post(String author, String title) { // ... } } // Get a reference to our posts final FirebaseDatabase database = FirebaseDatabase.getInstance(); DatabaseReference ref = database.getReference("server/saving-data/fireblog/posts"); // Attach a listener to read the data at our posts reference ref.addValueEventListener(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { Post post = dataSnapshot.getValue(Post.class); System.out.println(post); } @Override public void onCancelled(DatabaseError databaseError) { System.out.println("The read failed: " + databaseError.getCode()); } }); </pre> </section> <section> <h5 id="node.js" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Import Admin SDK var admin = require("firebase-admin"); // Get a database reference to our posts var db = admin.database(); var ref = db.ref("server/saving-data/fireblog/posts"); // Attach an asynchronous callback to read the data at our posts reference ref.on("value", function(snapshot) { console.log(snapshot.val()); }, function (errorObject) { console.log("The read failed: " + errorObject.code); }); </pre> </section> <section> <h5 id="python" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> # Import database module. from firebase_admin import db # Get a database reference to our posts ref = db.reference('server/saving-data/fireblog/posts') # Read the data at the posts reference (this is a blocking operation) print(ref.get()) </pre> </section> <section> <h5 id="go" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Post is a json-serializable type. type Post struct { Author string `json:"author,omitempty"` Title string `json:"title,omitempty"` } // Create a database client from App. client, err := app.Database(ctx) if err != nil { log.Fatalln("Error initializing database client:", err) } // Get a database reference to our posts ref := client.NewRef("server/saving-data/fireblog/posts") // Read the data at the posts reference (this is a blocking operation) var post Post if err := ref.Get(ctx, &post); err != nil { log.Fatalln("Error reading value:", err) } </pre> </section> </div> <aside> In Java and Node.js, you can pass an optional cancel callback to an event subscription that is called if the read is ever cancelled. A read would be cancelled if the app client doesn't have permission to read from that database reference. This callback is passed an <code translate="no" dir="ltr">error</code> object indicating why the failure occurred. In Python and Go, the <code translate="no" dir="ltr">get()</code> / <code translate="no" dir="ltr">Get()</code> operation fails by raising an exception in case of an error. </aside> <p>If you run the above code, you'll see an object containing all your posts logged to the console. <strong>In case of Node.js and Java, the listener function is called anytime new data is added to your database reference, and you don't need to write any extra code to make this happen.</strong></p> <p>In Java and Node.js, the callback function receives a <code translate="no" dir="ltr">DataSnapshot</code>, which is a snapshot of the data. A snapshot is a picture of the data at a particular database reference at a single point in time. Calling <code translate="no" dir="ltr">val()</code> / <code translate="no" dir="ltr">getValue()</code> on a snapshot returns the a language-specific object representation of the data. If no data exists at the reference's location, the snapshot's value is <code translate="no" dir="ltr">null</code>. The <code translate="no" dir="ltr">get()</code> method in Python returns a Python representation of the data directly. The <code translate="no" dir="ltr">Get()</code> function in Go unmarshals the data into a given data structure.</p> <p>Notice that we used the <code translate="no" dir="ltr">value</code> event type in the example above, which reads the entire contents of a Firebase database reference, even if only one piece of data changed. <code translate="no" dir="ltr">value</code> is one of the five different event types listed below that you can use to read data from the database.</p>  <h2 id="section-event-types" data-text="Read Event Types in Java and Node.js" tabindex="0">Read Event Types in Java and Node.js</h2> <h3 id="value" data-text="Value" tabindex="0">Value</h3> <p> The <code translate="no" dir="ltr">value</code> event is used to read a static snapshot of the contents at a given database path, as they existed at the time of the read event. It is triggered once with the initial data and again every time the data changes. The event callback is passed a snapshot containing all data at that location, including child data. In the code example above, <code translate="no" dir="ltr">value</code> returned all of the blog posts in your app. Everytime a new blog post is added, the callback function will return all of the posts. </p> <h3 id="child-added" data-text="Child Added" tabindex="0">Child Added</h3> <p> The <code translate="no" dir="ltr">child_added</code> event is typically used when retrieving a list of items from the database. Unlike <code translate="no" dir="ltr">value</code> which returns the entire contents of the location, <code translate="no" dir="ltr">child_added</code> is triggered once for each existing child and then again every time a new child is added to the specified path. The event callback is passed a snapshot containing the new child's data. For ordering purposes, it is also passed a second argument containing the key of the previous child. </p> <p>If you want to retrieve only the data on each new post added to your blogging app, you could use <code translate="no" dir="ltr">child_added</code>:</p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_1" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref.addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { Post newPost = dataSnapshot.getValue(Post.class); System.out.println("Author: " + newPost.author); System.out.println("Title: " + newPost.title); System.out.println("Previous Post ID: " + prevChildKey); } @Override public void onChildChanged(DataSnapshot dataSnapshot, String prevChildKey) {} @Override public void onChildRemoved(DataSnapshot dataSnapshot) {} @Override public void onChildMoved(DataSnapshot dataSnapshot, String prevChildKey) {} @Override public void onCancelled(DatabaseError databaseError) {} }); </pre> </section> <section> <h5 id="node.js_1" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Retrieve new posts as they are added to our database ref.on("child_added", function(snapshot, prevChildKey) { var newPost = snapshot.val(); console.log("Author: " + newPost.author); console.log("Title: " + newPost.title); console.log("Previous Post ID: " + prevChildKey); }); </pre> </section> </div> <p>In this example the snapshot will contain an object with an individual blog post. Because the SDK converts posts to objects by retrieving the value, you have access to the post's author and title properties by calling <code translate="no" dir="ltr">author</code> and <code translate="no" dir="ltr">title</code> respectively. You also have access to the previous post ID from the second <code translate="no" dir="ltr">prevChildKey</code> argument.</p> <h3 id="child-changed" data-text="Child Changed" tabindex="0">Child Changed</h3> <p> The <code translate="no" dir="ltr">child_changed</code> event is triggered any time a child node is modified. This includes any modifications to descendants of the child node. It is typically used in conjunction with <code translate="no" dir="ltr">child_added</code> and <code translate="no" dir="ltr">child_removed</code> to respond to changes to a list of items. The snapshot passed to the event callback contains the updated data for the child. </p> <p>You can use <code translate="no" dir="ltr">child_changed</code> to read updated data on blog posts when they are edited:</p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_2" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref.addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) {} @Override public void onChildChanged(DataSnapshot dataSnapshot, String prevChildKey) { Post changedPost = dataSnapshot.getValue(Post.class); System.out.println("The updated post title is: " + changedPost.title); } @Override public void onChildRemoved(DataSnapshot dataSnapshot) {} @Override public void onChildMoved(DataSnapshot dataSnapshot, String prevChildKey) {} @Override public void onCancelled(DatabaseError databaseError) {} }); </pre> </section> <section> <h5 id="node.js_2" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Get the data on a post that has changed ref.on("child_changed", function(snapshot) { var changedPost = snapshot.val(); console.log("The updated post title is " + changedPost.title); }); </pre> </section> </div> <h3 id="child-removed" data-text="Child Removed" tabindex="0">Child Removed</h3> <p> The <code translate="no" dir="ltr">child_removed</code> event is triggered when an immediate child is removed. It is typically used in conjunction with <code translate="no" dir="ltr">child_added</code> and <code translate="no" dir="ltr">child_changed</code>. The snapshot passed to the event callback contains the data for the removed child. </p> <p>In the blog example, you can use <code translate="no" dir="ltr">child_removed</code> to log a notification about the deleted post to the console:</p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_3" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref.addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) {} @Override public void onChildChanged(DataSnapshot dataSnapshot, String prevChildKey) {} @Override public void onChildRemoved(DataSnapshot dataSnapshot) { Post removedPost = dataSnapshot.getValue(Post.class); System.out.println("The blog post titled " + removedPost.title + " has been deleted"); } @Override public void onChildMoved(DataSnapshot dataSnapshot, String prevChildKey) {} @Override public void onCancelled(DatabaseError databaseError) {} }); </pre> </section> <section> <h5 id="node.js_3" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Get a reference to our posts var ref = db.ref("server/saving-data/fireblog/posts"); // Get the data on a post that has been removed ref.on("child_removed", function(snapshot) { var deletedPost = snapshot.val(); console.log("The blog post titled '" + deletedPost.title + "' has been deleted"); }); </pre> </section> </div> <h3 id="child-moved" data-text="Child Moved" tabindex="0">Child Moved</h3> <p> The <code translate="no" dir="ltr">child_moved</code> event is used when working with ordered data, which is covered in the <a href="#section-ordered-data">next section</a>. </p>  <h2 id="section-event-guarantees" data-text="Event Guarantees" tabindex="0">Event Guarantees</h2> <p>The Firebase database makes several important guarantees regarding events:</p> <table> <tr> <th class="text-center">Database Event Guarantees</th> </tr> <tr> <td>Events will always be triggered when local state changes.</td> </tr> <tr> <td> Events will always eventually reflect the correct state of the data, even in cases where local operations or timing cause temporary differences, such as in the temporary loss of network connection. </td> </tr> <tr> <td>Writes from a single client will always be written to the server and broadcast out to other users in-order.</td> </tr> <tr> <td>Value events are always triggered last and are guaranteed to contain updates from any other events which occurred before that snapshot was taken.</td> </tr> </table> <p> Since value events are always triggered last, the following example will always work: </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_4" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> final AtomicInteger count = new AtomicInteger(); ref.addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { // New child added, increment count int newCount = count.incrementAndGet(); System.out.println("Added " + dataSnapshot.getKey() + ", count is " + newCount); } // ... }); // The number of children will always be equal to 'count' since the value of // the dataSnapshot here will include every child_added event triggered before this point. ref.addListenerForSingleValueEvent(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { long numChildren = dataSnapshot.getChildrenCount(); System.out.println(count.get() + " == " + numChildren); } @Override public void onCancelled(DatabaseError databaseError) {} }); </pre> </section> <section> <h5 id="node.js_4" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var count = 0; ref.on("child_added", function(snap) { count++; console.log("added:", snap.key); }); // length will always equal count, since snap.val() will include every child_added event // triggered before this point ref.once("value", function(snap) { console.log("initial data loaded!", snap.numChildren() === count); }); </pre> </section> </div>  <h2 id="section-detaching-callbacks" data-text="Detaching Callbacks" tabindex="0">Detaching Callbacks</h2> <p>Callbacks are removed by specifying the event type and the callback function to be removed, like the following:</p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_5" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Create and attach listener ValueEventListener listener = new ValueEventListener() { // ... }; ref.addValueEventListener(listener); // Remove listener ref.removeEventListener(listener); </pre> </section> <section> <h5 id="node.js_5" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref.off("value", originalCallback); </pre> </section> </div> <p>If you passed a scope context into <code translate="no" dir="ltr">on()</code>, it must be passed when detaching the callback:</p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_6" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Not applicable for Java </pre> </section> <section> <h5 id="node.js_6" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref.off("value", originalCallback, this); </pre> </section> </div> <aside class="special">If a callback has been added multiple times to a data location, it is called multiple times for each event and you must detach it multiple times in order to remove it completely.</aside> <p>If you would like to remove all callbacks at a location, you can do the following:</p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_7" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> // No Java equivalent, listeners must be removed individually. </pre> </section> <section> <h5 id="node.js_7" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Remove all value callbacks ref.off("value"); // Remove all callbacks of any type ref.off(); </pre> </section> </div>  <h2 id="section-reading-once" data-text="Reading Data Once" tabindex="0">Reading Data Once</h2> <p> In some cases it may be useful for a callback to be called once and then immediately removed. We've created a helper function to make this easy: </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_8" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref.addListenerForSingleValueEvent(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { // ... } @Override public void onCancelled(DatabaseError databaseError) { // ... } }); </pre> </section> <section> <h5 id="node.js_8" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref.once("value", function(data) { // do some stuff once }); </pre> </section> <section> <h5 id="python_1" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> # Import database module. from firebase_admin import db # Get a database reference to our posts ref = db.reference('server/saving-data/fireblog/posts') # Read the data at the posts reference (this is a blocking operation) print(ref.get()) </pre> </section> <section> <h5 id="go_1" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Create a database client from App. client, err := app.Database(ctx) if err != nil { log.Fatalln("Error initializing database client:", err) } // Get a database reference to our posts ref := client.NewRef("server/saving-data/fireblog/posts") // Read the data at the posts reference (this is a blocking operation) var post Post if err := ref.Get(ctx, &post); err != nil { log.Fatalln("Error reading value:", err) } </pre> </section> </div>  <h2 id="section-queries" data-text="Querying Data" tabindex="0">Querying Data</h2> <p> With Firebase database queries, you can selectively retrieve data based on various factors. To construct a query in your database, you start by specifying how you want your data to be ordered using one of the ordering functions: <code translate="no" dir="ltr">orderByChild()</code>, <code translate="no" dir="ltr">orderByKey()</code>, or <code translate="no" dir="ltr">orderByValue()</code>. You can then combine these with five other methods to conduct complex queries: <code translate="no" dir="ltr">limitToFirst()</code>, <code translate="no" dir="ltr">limitToLast()</code>, <code translate="no" dir="ltr">startAt()</code>, <code translate="no" dir="ltr">endAt()</code>, and <code translate="no" dir="ltr">equalTo()</code>. </p> <p>Since all of us at Firebase think dinosaurs are pretty cool, we'll use a snippet from a sample database of dinosaur facts to demonstrate how you can query data in your Firebase database.:</p> <pre class="prettyprint" translate="no" dir="ltr"> { "lambeosaurus": { "height" : 2.1, "length" : 12.5, "weight": 5000 }, "stegosaurus": { "height" : 4, "length" : 9, "weight" : 2500 } } </pre> <p>You can order data in three ways: by <strong>child key</strong>, by <strong>key</strong>, or by <strong>value</strong>. A basic database query starts with one of these ordering functions, each of which are explained below.</p> <h3 id="ordering-by-a-specified-child-key" data-text="Ordering by a specified child key" tabindex="0">Ordering by a specified child key</h3> <p>You can order nodes by a common child key by passing that key to <code translate="no" dir="ltr">orderByChild()</code>. For example, to read all dinosaurs ordered by height, you can do the following: </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_9" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> public static class Dinosaur { public int height; public int weight; public Dinosaur(int height, int weight) { // ... } } final DatabaseReference dinosaursRef = database.getReference("dinosaurs"); dinosaursRef.orderByChild("height").addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { Dinosaur dinosaur = dataSnapshot.getValue(Dinosaur.class); System.out.println(dataSnapshot.getKey() + " was " + dinosaur.height + " meters tall."); } // ... }); </pre> </section> <section> <h5 id="node.js_9" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var db = firebaseAdmin.database(); var ref = db.ref("dinosaurs"); ref.orderByChild("height").on("child_added", function(snapshot) { console.log(snapshot.key + " was " + snapshot.val().height + " meters tall"); }); </pre> </section> <section> <h5 id="python_2" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref = db.reference('dinosaurs') snapshot = ref.order_by_child('height').get() for key, val in snapshot.items(): print('{0} was {1} meters tall'.format(key, val)) </pre> </section> <section> <h5 id="go_2" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Dinosaur is a json-serializable type. type Dinosaur struct { Height int `json:"height"` Width int `json:"width"` } ref := client.NewRef("dinosaurs") results, err := ref.OrderByChild("height").GetOrdered(ctx) if err != nil { log.Fatalln("Error querying database:", err) } for _, r := range results { var d Dinosaur if err := r.Unmarshal(&d); err != nil { log.Fatalln("Error unmarshaling result:", err) } fmt.Printf("%s was %d meteres tall", r.Key(), d.Height) } </pre> </section> </div> <p> Any node which does not have the child key we're querying on is sorted with a value of <code translate="no" dir="ltr">null</code>, meaning it will come first in the ordering. For details on how data is ordered, see the <a href="#section-ordered-data">How Data is Ordered section</a>. </p> <p> Queries can also be ordered by deeply nested children, rather than only children one level down. This is useful if you have deeply nested data like this: </p> <pre class="prettyprint" translate="no" dir="ltr"> { "lambeosaurus": { "dimensions": { "height" : 2.1, "length" : 12.5, "weight": 5000 } }, "stegosaurus": { "dimensions": { "height" : 4, "length" : 9, "weight" : 2500 } } } </pre> <p> To query the height now, you can use the full path to the object rather than a single key: </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_10" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> dinosaursRef.orderByChild("dimensions/height").addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { // ... } // ... }); </pre> </section> <section> <h5 id="node.js_10" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var ref = db.ref("dinosaurs"); ref.orderByChild("dimensions/height").on("child_added", function(snapshot) { console.log(snapshot.key + " was " + snapshot.val().height + " meters tall"); }); </pre> </section> <section> <h5 id="python_3" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref = db.reference('dinosaurs') snapshot = ref.order_by_child('dimensions/height').get() for key, val in snapshot.items(): print('{0} was {1} meters tall'.format(key, val)) </pre> </section> <section> <h5 id="go_3" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.NewRef("dinosaurs") results, err := ref.OrderByChild("dimensions/height").GetOrdered(ctx) if err != nil { log.Fatalln("Error querying database:", err) } for _, r := range results { var d Dinosaur if err := r.Unmarshal(&d); err != nil { log.Fatalln("Error unmarshaling result:", err) } fmt.Printf("%s was %d meteres tall", r.Key(), d.Height) } </pre> </section> </div> <p> Queries can only order by one key at a time. Calling <code translate="no" dir="ltr">orderByChild()</code> multiple times on the same query throws an error. </p> <aside class="special"> <h4 id="using-indexes-for-improved-performance" data-text="Using Indexes For Improved Performance" tabindex="0">Using Indexes For Improved Performance</h4> <p> If you want to use <code translate="no" dir="ltr">orderByChild()</code> on a production app, you should define the keys you are indexing on via the <code translate="no" dir="ltr">.indexOn</code> rule in your Security and Firebase Rules. While you are allowed to create these queries ad-hoc on the client, you will see greatly improved performance when using <code translate="no" dir="ltr">.indexOn</code>. <a href="/web/20201004011617/https://firebase.google.com/docs/database/security/indexing-data">Read the documentation</a> on the <code translate="no" dir="ltr">.indexOn</code> rule for more information. </p> </aside> <h3 id="ordering-by-key" data-text="Ordering by key" tabindex="0">Ordering by key</h3> <p> You can also order nodes by their keys using the <code translate="no" dir="ltr">orderByKey()</code> method. The following example reads all dinosaurs in alphabetical order: </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_11" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> dinosaursRef.orderByKey().addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { System.out.println(dataSnapshot.getKey()); } // ... }); </pre> </section> <section> <h5 id="node.js_11" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var ref = db.ref("dinosaurs"); ref.orderByKey().on("child_added", function(snapshot) { console.log(snapshot.key); }); </pre> </section> <section> <h5 id="python_4" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref = db.reference('dinosaurs') snapshot = ref.order_by_key().get() print(snapshot) </pre> </section> <section> <h5 id="go_4" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.NewRef("dinosaurs") results, err := ref.OrderByKey().GetOrdered(ctx) if err != nil { log.Fatalln("Error querying database:", err) } snapshot := make([]Dinosaur, len(results)) for i, r := range results { var d Dinosaur if err := r.Unmarshal(&d); err != nil { log.Fatalln("Error unmarshaling result:", err) } snapshot[i] = d } fmt.Println(snapshot) </pre> </section> </div> <h3 id="ordering-by-value" data-text="Ordering by value" tabindex="0">Ordering by value</h3> <p>You can order nodes by the value of their child keys using the <code translate="no" dir="ltr">orderByValue()</code> method. Let's say the dinosaurs are having a dino sports competition and you're keeping track of their scores in the following format: </p> <pre class="prettyprint" translate="no" dir="ltr"> { "scores": { "bruhathkayosaurus" : 55, "lambeosaurus" : 21, "linhenykus" : 80, "pterodactyl" : 93, "stegosaurus" : 5, "triceratops" : 22 } } </pre> <p>To sort the dinosaurs by their score, you could construct the following query:</p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_12" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> DatabaseReference scoresRef = database.getReference("scores"); scoresRef.orderByValue().addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { System.out.println("The " + dataSnapshot.getKey() + " score is " + dataSnapshot.getValue()); } // ... }); </pre> </section> <section> <h5 id="node.js_12" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var scoresRef = db.ref("scores"); scoresRef.orderByValue().on("value", function(snapshot) { snapshot.forEach(function(data) { console.log("The " + data.key + " dinosaur's score is " + data.val()); }); }); </pre> </section> <section> <h5 id="python_5" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref = db.reference('scores') snapshot = ref.order_by_value().get() for key, val in snapshot.items(): print('The {0} dinosaur\'s score is {1}'.format(key, val)) </pre> </section> <section> <h5 id="go_5" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.NewRef("scores") results, err := ref.OrderByValue().GetOrdered(ctx) if err != nil { log.Fatalln("Error querying database:", err) } for _, r := range results { var score int if err := r.Unmarshal(&score); err != nil { log.Fatalln("Error unmarshaling result:", err) } fmt.Printf("The %s dinosaur's score is %d\n", r.Key(), score) } </pre> </section> </div> <p>See the <a href="#section-ordered-data">How Data is Ordered</a> section for an explanation on how <code translate="no" dir="ltr">null</code>, boolean, string, and object values are sorted when using <code translate="no" dir="ltr">orderByValue()</code>.</p> <aside class="special"> <h4 id="indexing-on-values-for-improved-performance" data-text="Indexing on Values for Improved Performance" tabindex="0">Indexing on Values for Improved Performance</h4> <p> If you want to use <code translate="no" dir="ltr">orderByValue()</code> in a production app, you should add <code translate="no" dir="ltr">.value</code> to your rules at the appropriate index. <a href="/web/20201004011617/https://firebase.google.com/docs/database/security/indexing-data">Read the documentation</a> on the <code translate="no" dir="ltr">.indexOn</code> rule for more information. </p> </aside>  <h2 id="section-complex-queries" data-text="Complex Queries" tabindex="0">Complex Queries</h2> <p>Now that it is clear how your data is ordered, you can use the <strong>limit</strong> or <strong>range</strong> methods described below to construct more complex queries.</p> <h3 id="limit-queries" data-text="Limit Queries" tabindex="0">Limit Queries</h3> <p> The <code translate="no" dir="ltr">limitToFirst()</code> and <code translate="no" dir="ltr">limitToLast()</code> queries are used to set a maximum number of children to be synced for a given callback. If you set a limit of 100, you will initially only receive up to 100 <code translate="no" dir="ltr">child_added</code> events. If you have fewer than 100 messages stored in your database, a <code translate="no" dir="ltr">child_added</code> event will fire for each message. However, if you have over 100 messages, you will only receive a <code translate="no" dir="ltr">child_added</code> event for 100 of those messages. These are the first 100 ordered messages if you are using <code translate="no" dir="ltr">limitToFirst()</code> or the last 100 ordered messages if you are using <code translate="no" dir="ltr">limitToLast()</code>. As items change, you will receive <code translate="no" dir="ltr">child_added</code> events for items that enter the query and <code translate="no" dir="ltr">child_removed</code> events for items that leave it, so that the total number stays at 100. </p> <p> Using the dinosaur facts database and <code translate="no" dir="ltr">orderByChild()</code>, you can find the two heaviest dinosaurs: </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_13" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> dinosaursRef.orderByChild("weight").limitToLast(2).addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { System.out.println(dataSnapshot.getKey()); } // ... }); </pre> </section> <section> <h5 id="node.js_13" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var ref = db.ref("dinosaurs"); ref.orderByChild("weight").limitToLast(2).on("child_added", function(snapshot) { console.log(snapshot.key); }); </pre> </section> <section> <h5 id="python_6" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref = db.reference('dinosaurs') snapshot = ref.order_by_child('weight').limit_to_last(2).get() for key in snapshot: print(key) </pre> </section> <section> <h5 id="go_6" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.NewRef("dinosaurs") results, err := ref.OrderByChild("weight").LimitToLast(2).GetOrdered(ctx) if err != nil { log.Fatalln("Error querying database:", err) } for _, r := range results { fmt.Println(r.Key()) } </pre> </section> </div> <p> The <code translate="no" dir="ltr">child_added</code> callback is triggered exactly two times, unless there are less than two dinosaurs stored in the database. It will also get fired for every new, heavier dinosaur that gets added to the database. In Python, the query directly returns an <code translate="no" dir="ltr">OrderedDict</code> containing the two heaviest dinosaurs. </p> <p> Similarly, you can find the two shortest dinosaurs by using <code translate="no" dir="ltr">limitToFirst()</code>: </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_14" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> dinosaursRef.orderByChild("weight").limitToFirst(2).addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { System.out.println(dataSnapshot.getKey()); } // ... }); </pre> </section> <section> <h5 id="node.js_14" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var ref = db.ref("dinosaurs"); ref.orderByChild("height").limitToFirst(2).on("child_added", function(snapshot) { console.log(snapshot.key); }); </pre> </section> <section> <h5 id="python_7" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref = db.reference('dinosaurs') snapshot = ref.order_by_child('height').limit_to_first(2).get() for key in snapshot: print(key) </pre> </section> <section> <h5 id="go_7" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.NewRef("dinosaurs") results, err := ref.OrderByChild("height").LimitToFirst(2).GetOrdered(ctx) if err != nil { log.Fatalln("Error querying database:", err) } for _, r := range results { fmt.Println(r.Key()) } </pre> </section> </div> <p> The <code translate="no" dir="ltr">child_added</code> callback is triggered exactly two times, unless there are less than two dinosaurs stored in the database. It will also get fired again if one of the first two dinosaurs is removed from the database, as a new dinosaur will now be the second shortest. In Python, the query directly returns an <code translate="no" dir="ltr">OrderedDict</code> containing the shortest dinosaurs. </p> <p>You can also conduct limit queries with <code translate="no" dir="ltr">orderByValue()</code>. If you want to create a leaderboard with the top 3 highest scoring dino sports dinosaurs, you could do the following:</p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_15" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> scoresRef.orderByValue().limitToFirst(3).addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { System.out.println("The " + dataSnapshot.getKey() + " score is " + dataSnapshot.getValue()); } // ... }); </pre> </section> <section> <h5 id="node.js_15" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var scoresRef = db.ref("scores"); scoresRef.orderByValue().limitToLast(3).on("value", function(snapshot) { snapshot.forEach(function(data) { console.log("The " + data.key + " dinosaur's score is " + data.val()); }); }); </pre> </section> <section> <h5 id="python_8" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> scores_ref = db.reference('scores') snapshot = scores_ref.order_by_value().limit_to_last(3).get() for key, val in snapshot.items(): print('The {0} dinosaur\'s score is {1}'.format(key, val)) </pre> </section> <section> <h5 id="go_8" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.NewRef("scores") results, err := ref.OrderByValue().LimitToLast(3).GetOrdered(ctx) if err != nil { log.Fatalln("Error querying database:", err) } for _, r := range results { var score int if err := r.Unmarshal(&score); err != nil { log.Fatalln("Error unmarshaling result:", err) } fmt.Printf("The %s dinosaur's score is %d\n", r.Key(), score) } </pre> </section> </div> <h3 id="range-queries" data-text="Range Queries" tabindex="0">Range Queries</h3> <p> Using <code translate="no" dir="ltr">startAt()</code>, <code translate="no" dir="ltr">endAt()</code>, and <code translate="no" dir="ltr">equalTo()</code> allows you to choose arbitrary starting and ending points for your queries. For example, if you wanted to find all dinosaurs that are at least three meters tall, you can combine <code translate="no" dir="ltr">orderByChild()</code> and <code translate="no" dir="ltr">startAt()</code>: </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_16" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> dinosaursRef.orderByChild("height").startAt(3).addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { System.out.println(dataSnapshot.getKey()); } // ... }); </pre> </section> <section> <h5 id="node.js_16" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var ref = db.ref("dinosaurs"); ref.orderByChild("height").startAt(3).on("child_added", function(snapshot) { console.log(snapshot.key); }); </pre> </section> <section> <h5 id="python_9" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref = db.reference('dinosaurs') snapshot = ref.order_by_child('height').start_at(3).get() for key in snapshot: print(key) </pre> </section> <section> <h5 id="go_9" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.NewRef("dinosaurs") results, err := ref.OrderByChild("height").StartAt(3).GetOrdered(ctx) if err != nil { log.Fatalln("Error querying database:", err) } for _, r := range results { fmt.Println(r.Key()) } </pre> </section> </div> <p> You can use <code translate="no" dir="ltr">endAt()</code> to find all dinosaurs whose names come before Pterodactyl lexicographically: </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_17" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> dinosaursRef.orderByKey().endAt("pterodactyl").addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { System.out.println(dataSnapshot.getKey()); } // ... }); </pre> </section> <section> <h5 id="node.js_17" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var ref = db.ref("dinosaurs"); ref.orderByKey().endAt("pterodactyl").on("child_added", function(snapshot) { console.log(snapshot.key); }); </pre> </section> <section> <h5 id="python_10" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref = db.reference('dinosaurs') snapshot = ref.order_by_key().end_at('pterodactyl').get() for key in snapshot: print(key) </pre> </section> <section> <h5 id="go_10" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.NewRef("dinosaurs") results, err := ref.OrderByKey().EndAt("pterodactyl").GetOrdered(ctx) if err != nil { log.Fatalln("Error querying database:", err) } for _, r := range results { fmt.Println(r.Key()) } </pre> </section> </div> <aside class="special"> <code translate="no" dir="ltr">startAt()</code> and <code translate="no" dir="ltr">endAt()</code> are inclusive, meaning "pterodactyl" will match the query above. </aside> <p> You can combine <code translate="no" dir="ltr">startAt()</code> and <code translate="no" dir="ltr">endAt()</code> to limit both ends of your query. The following example finds all dinosaurs whose name starts with the letter "b": </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_18" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> dinosaursRef.orderByKey().startAt("b").endAt("b\uf8ff").addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { System.out.println(dataSnapshot.getKey()); } // ... }); </pre> </section> <section> <h5 id="node.js_18" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var ref = db.ref("dinosaurs"); ref.orderByKey().startAt("b").endAt("b\uf8ff").on("child_added", function(snapshot) { console.log(snapshot.key); }); </pre> </section> <section> <h5 id="python_11" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref = db.reference('dinosaurs') snapshot = ref.order_by_key().start_at('b').end_at(u'b\uf8ff').get() for key in snapshot: print(key) </pre> </section> <section> <h5 id="go_11" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.NewRef("dinosaurs") results, err := ref.OrderByKey().StartAt("b").EndAt("b\uf8ff").GetOrdered(ctx) if err != nil { log.Fatalln("Error querying database:", err) } for _, r := range results { fmt.Println(r.Key()) } </pre> </section> </div> <aside class="special"> The <code translate="no" dir="ltr">\uf8ff</code> character used in the query above is a very high code point in the Unicode range. Because it is after most regular characters in Unicode, the query matches all values that start with a b. </aside> <p> The <code translate="no" dir="ltr">equalTo()</code> method allows you to filter based on exact matches. As is the case with the other range queries, it will fire for each matching child node. For example, you can use the following query to find all dinosaurs which are 25 meters tall: </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_19" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> dinosaursRef.orderByChild("height").equalTo(25).addChildEventListener(new ChildEventListener() { @Override public void onChildAdded(DataSnapshot dataSnapshot, String prevChildKey) { System.out.println(dataSnapshot.getKey()); } // ... }); </pre> </section> <section> <h5 id="node.js_19" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var ref = db.ref("dinosaurs"); ref.orderByChild("height").equalTo(25).on("child_added", function(snapshot) { console.log(snapshot.key); }); </pre> </section> <section> <h5 id="python_12" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref = db.reference('dinosaurs') snapshot = ref.order_by_child('height').equal_to(25).get() for key in snapshot: print(key) </pre> </section> <section> <h5 id="go_12" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.NewRef("dinosaurs") results, err := ref.OrderByChild("height").EqualTo(25).GetOrdered(ctx) if err != nil { log.Fatalln("Error querying database:", err) } for _, r := range results { fmt.Println(r.Key()) } </pre> </section> </div> <p> Range queries are also useful when you need to paginate your data. </p> <aside class="special">You can also combine <code translate="no" dir="ltr">orderByValue()</code> with <code translate="no" dir="ltr">startAt()</code> and <code translate="no" dir="ltr">endAt()</code> to construct range queries.</aside> <h3 id="putting-it-all-together" data-text="Putting it all together" tabindex="0">Putting it all together</h3> <p> You can combine all of these techniques to create complex queries. For example, you can find the name of the dinosaur that is just shorter than Stegosaurus: </p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="java_20" data-text="Java" tabindex="0">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> dinosaursRef.child("stegosaurus").child("height").addValueEventListener(new ValueEventListener() { @Override public void onDataChange(DataSnapshot stegoHeightSnapshot) { Integer favoriteDinoHeight = stegoHeightSnapshot.getValue(Integer.class); Query query = dinosaursRef.orderByChild("height").endAt(favoriteDinoHeight).limitToLast(2); query.addValueEventListener(new ValueEventListener() { @Override public void onDataChange(DataSnapshot dataSnapshot) { // Data is ordered by increasing height, so we want the first entry DataSnapshot firstChild = dataSnapshot.getChildren().iterator().next(); System.out.println("The dinosaur just shorter than the stegosaurus is: " + firstChild.getKey()); } @Override public void onCancelled(DatabaseError databaseError) { // ... } }); } @Override public void onCancelled(DatabaseError databaseError) { // ... } }); </pre> </section> <section> <h5 id="node.js_20" data-text="Node.js" tabindex="0">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> var ref = db.ref("dinosaurs"); ref.child("stegosaurus").child("height").on("value", function(stegosaurusHeightSnapshot) { var favoriteDinoHeight = stegosaurusHeightSnapshot.val(); var queryRef = ref.orderByChild("height").endAt(favoriteDinoHeight).limitToLast(2) queryRef.on("value", function(querySnapshot) { if (querySnapshot.numChildren() === 2) { // Data is ordered by increasing height, so we want the first entry querySnapshot.forEach(function(dinoSnapshot) { console.log("The dinosaur just shorter than the stegasaurus is " + dinoSnapshot.key); // Returning true means that we will only loop through the forEach() one time return true; }); } else { console.log("The stegosaurus is the shortest dino"); } }); }); </pre> </section> <section> <h5 id="python_13" data-text="Python" tabindex="0">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref = db.reference('dinosaurs') favotire_dino_height = ref.child('stegosaurus').child('height').get() query = ref.order_by_child('height').end_at(favotire_dino_height).limit_to_last(2) snapshot = query.get() if len(snapshot) == 2: # Data is ordered by increasing height, so we want the first entry. # Second entry is stegosarus. for key in snapshot: print('The dinosaur just shorter than the stegosaurus is {0}'.format(key)) return else: print('The stegosaurus is the shortest dino') </pre> </section> <section> <h5 id="go_13" data-text="Go" tabindex="0">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.NewRef("dinosaurs") var favDinoHeight int if err := ref.Child("stegosaurus").Child("height").Get(ctx, &favDinoHeight); err != nil { log.Fatalln("Error querying database:", err) } query := ref.OrderByChild("height").EndAt(favDinoHeight).LimitToLast(2) results, err := query.GetOrdered(ctx) if err != nil { log.Fatalln("Error querying database:", err) } if len(results) == 2 { // Data is ordered by increasing height, so we want the first entry. // Second entry is stegosarus. fmt.Printf("The dinosaur just shorter than the stegosaurus is %s\n", results[0].Key()) } else { fmt.Println("The stegosaurus is the shortest dino") } </pre> </section> </div>  <h2 id="section-ordered-data" data-text="How Data is Ordered" tabindex="0">How Data is Ordered</h2> <p> This section explains how your data is ordered when using each of the four ordering functions. </p> <h3 id="orderbychild" data-text="orderByChild" tabindex="0">orderByChild</h3> <p>When using <code translate="no" dir="ltr">orderByChild()</code>, data that contains the specified child key is ordered as follows:</p> <ol> <li>Children with a <code translate="no" dir="ltr">null</code> value for the specified child key come first.</li> <li>Children with a value of <code translate="no" dir="ltr">false</code> for the specified child key come next. If multiple children have a value of <code translate="no" dir="ltr">false</code>, they are sorted <a href="https://web.archive.org/web/20201004011617/http://en.wikipedia.org/wiki/Lexicographical_order">lexicographically</a> by key.</li> <li>Children with a value of <code translate="no" dir="ltr">true</code> for the specified child key come next. If multiple children have a value of <code translate="no" dir="ltr">true</code>, they are sorted lexicographically by key.</li> <li>Children with a numeric value come next, sorted in ascending order. If multiple children have the same numerical value for the specified child node, they are sorted by key.</li> <li>Strings come after numbers, and are sorted lexicographically in ascending order. If multiple children have the same value for the specified child node, they are ordered lexicographically by key.</li> <li>Objects come last, and sorted lexicographically by key in ascending order.</li> </ol> <h3 id="orderbykey" data-text="orderByKey" tabindex="0">orderByKey</h3> <p>When using <code translate="no" dir="ltr">orderByKey()</code> to sort your data, data is returned in ascending order by key as follows. Keep in mind that keys can only be strings.</p> <ol> <li>Children with a key that can be parsed as a 32-bit integer come first, sorted in ascending order.</li> <li>Children with a string value as their key come next, sorted lexicographically in ascending order.</li> </ol> <h3 id="orderbyvalue" data-text="orderByValue" tabindex="0">orderByValue</h3> <p>When using <code translate="no" dir="ltr">orderByValue()</code>, children are ordered by their value. The ordering criteria is the same as in <code translate="no" dir="ltr">orderByChild()</code>, except the value of the node is used instead of the value of a specified child key.</p> </div> </div> <devsite-page-rating position="footer" selected-rating="0" hover-rating-star="0"> </devsite-page-rating> <devsite-feedback position="footer" project-name="Firebase Realtime Database" product-id="719752" bucket="" context="" version="t-devsite-webserver-20200924-r01-rc00.429872899142986475" data-label="Send Feedback Button" track-type="feedback" track-name="sendFeedbackLink" track-metadata-position="footer" project-feedback-url="https://firebase.google.com/support/contact/bugs-features/" project-icon="https://www.gstatic.com/devrel-devsite/prod/v85e39fe21f53c758adf6c791fb94a7a2182cff2705b3dc8ed7c59fc745471159/firebase/images/touchicon-180.png" project-support-url="https://firebase.google.com/support/"> <button> Send feedback </button> </devsite-feedback> </article> </article> <devsite-content-footer class="nocontent"> <p>Except as otherwise noted, the content of this page is licensed under the <a href="https://web.archive.org/web/20201004011617/https://creativecommons.org/licenses/by/4.0/">Creative Commons Attribution 4.0 License</a>, and code samples are licensed under the <a href="https://web.archive.org/web/20201004011617/https://www.apache.org/licenses/LICENSE-2.0">Apache 2.0 License</a>. 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