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<devsite-progress type="indeterminate" id="app-progress"></devsite-progress> <section class="devsite-wrapper"><devsite-header> <div class="devsite-header--inner nocontent"> <div class="devsite-top-logo-row-wrapper-wrapper"> <div class="devsite-top-logo-row-wrapper"> <div class="devsite-top-logo-row"> <button type="button" id="devsite-hamburger-menu" class="devsite-header-icon-button button-flat material-icons gc-analytics-event" data-category="Site-Wide Custom Events" data-label="Navigation menu button" visually-hidden aria-label="Open menu"> </button> <div class="devsite-product-name-wrapper"> <a href="/web/20210127075900/https://firebase.google.com/" class="devsite-site-logo-link gc-analytics-event" data-category="Site-Wide Custom Events" data-label="Site logo" track-type="globalNav" track-name="firebase" track-metadata-position="nav" track-metadata-eventdetail="nav"> <img 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track-type="globalNav" track-metadata-position="nav" track-metadata-eventdetail="nav" track-name="guides" aria-label="Guides, selected" data-category="Site-Wide Custom Events" data-label="Tab: Guides"> Guides </a> </tab> <tab> <a href="https://web.archive.org/web/20210127075900/https://firebase.google.com/docs/reference" class="gc-analytics-event " track-type="globalNav" track-metadata-position="nav" track-metadata-eventdetail="nav" track-name="reference" data-category="Site-Wide Custom Events" data-label="Tab: Reference"> Reference </a> </tab> <tab> <a href="https://web.archive.org/web/20210127075900/https://firebase.google.com/docs/samples" class="gc-analytics-event " track-type="globalNav" track-metadata-position="nav" track-metadata-eventdetail="nav" track-name="samples" data-category="Site-Wide Custom Events" data-label="Tab: Samples"> Samples </a> </tab> <tab> <a href="https://web.archive.org/web/20210127075900/https://firebase.google.com/docs/libraries" class="gc-analytics-event 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class="devsite-nav-responsive-tabs devsite-nav-has-menu "> <li class="devsite-nav-item"> <span class="devsite-nav-title" tooltip> <span class="devsite-nav-text" tooltip menu="Products"> More </span> <span class="devsite-nav-icon material-icons" data-icon="forward" menu="Products"> </span> </span> </li> </ul> </li> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/use-cases" class="devsite-nav-title gc-analytics-event devsite-nav-has-children " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Use Cases" track-type="globalNav" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="useCases"> <span class="devsite-nav-text" tooltip> Use Cases </span> <span class="devsite-nav-icon material-icons" data-icon="forward"> </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/pricing" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Pricing" track-type="globalNav" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="pricing"> <span class="devsite-nav-text" tooltip> Pricing </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/docs" class="devsite-nav-title gc-analytics-event devsite-nav-active" data-category="Site-Wide Custom Events" data-label="Responsive Tab: Docs" track-type="globalNav" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="docs"> <span class="devsite-nav-text" tooltip> Docs </span> </a> <ul class="devsite-nav-responsive-tabs"> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/docs" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Overview" track-type="globalNav" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="overview"> <span class="devsite-nav-text" tooltip> Overview </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/docs/guides" class="devsite-nav-title gc-analytics-event devsite-nav-has-children devsite-nav-active" data-category="Site-Wide Custom Events" data-label="Responsive Tab: Guides" track-type="globalNav" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="guides"> <span class="devsite-nav-text" tooltip menu="_book"> Guides </span> <span class="devsite-nav-icon material-icons" data-icon="forward" menu="_book"> </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/docs/reference" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Reference" track-type="globalNav" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="reference"> <span class="devsite-nav-text" tooltip> Reference </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/docs/samples" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Samples" track-type="globalNav" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="samples"> <span class="devsite-nav-text" tooltip> Samples </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/docs/libraries" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Libraries" track-type="globalNav" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="libraries"> <span class="devsite-nav-text" tooltip> Libraries </span> </a> </li> </ul> </li> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/community" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Community" track-type="globalNav" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="community"> <span class="devsite-nav-text" tooltip> Community </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/support" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Support" track-type="globalNav" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="support"> <span class="devsite-nav-text" tooltip> Support </span> </a> </li> <li class="devsite-nav-item"> <a href="//web.archive.org/web/20210127075900/https://console.firebase.google.com/" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Go to console" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="goToConsole"> <span class="devsite-nav-text" tooltip> Go to console </span> </a> </li> </ul> </div> <div class="devsite-mobile-nav-bottom" role="navigation"> <ul class="devsite-nav-list" menu="_book"> <li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/guides" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Guides</span></a></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>Get started with Firebase</span></div><ul class="devsite-nav-section"><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 an app</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/ios/setup" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/https://firebase.google.com/docs/projects/api-keys" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Learn about API keys for Firebase</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/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/20210127075900/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/20210127075900/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-beta"><a href="/web/20210127075900/https://firebase.google.com/docs/projects/import-segments" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Import segments</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>Manage projects programmatically</span></div></li><li class="devsite-nav-item devsite-nav-beta"><a href="/web/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/https://firebase.google.com/docs/projects/iam/roles-basic" 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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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-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>Platforms and frameworks</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item devsite-nav-heading"><div class="devsite-nav-title devsite-nav-title-no-path"><span class="devsite-nav-text" tooltip>iOS</span></div></li><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/ios/link-firebase-static-dynamic" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Link Firebase dependencies statically or dynamically</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/ios/app-store-data-collection" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Prepare for Apple App Store data disclosure requirements</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>Android</span></div></li><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/android/learn-more" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Learn about Android + Firebase</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/android/android-play-services" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Dependencies of Firebase Android SDKs on Google Play services</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/android/integrate-play-games" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Integrate with your Play Games Services project</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>Web</span></div></li><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/web/environments-js-sdk" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Supported environments for the Firebase JS SDK</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/20210127075900/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/20210127075900/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/20210127075900/https://firebase.google.com/docs/emulator-suite/connect_auth" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Connect to the Authentication emulator</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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>Build</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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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 class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/firestore/transaction-data-contention" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Data contention in transaction</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/firestore/manage-data/delete-data" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Delete data</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/firestore/using-console" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage Cloud Firestore with the Firebase Console</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/firestore/manage-data/export-import" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Export and import data</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/firestore/security/rules-fields" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Control access per field</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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/https://firebase.google.com/docs/firestore/solutions/geoqueries" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Geo queries</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/https://firebase.google.com/docs/reference/admin/java/reference/com/google/firebase/cloud/FirestoreClient" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Java</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/reference/admin/python/firebase_admin.firestore" 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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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 devsite-nav-new"><a href="/web/20210127075900/https://firebase.google.com/docs/hosting/test-preview-deploy" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Test, preview, then deploy</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/20210127075900/https://firebase.google.com/docs/hosting/github-integration" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Deploy via GitHub pull requests</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/20210127075900/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/20210127075900/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/20210127075900/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"><a href="/web/20210127075900/https://firebase.google.com/docs/hosting/i18n-rewrites" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Configure i18n rewrites</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/https://firebase.google.com/docs/hosting/manage-hosting-resources" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Manage live & preview channels, releases, and versions</span></a></li><li class="devsite-nav-item devsite-nav-new"><a href="/web/20210127075900/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"><a href="/web/20210127075900/https://firebase.google.com/docs/hosting/usage-quotas-pricing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Usage, quotas, and pricing</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/https://firebase.google.com/docs/functions/pubsub-events" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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"><a href="/web/20210127075900/https://firebase.google.com/docs/ml/codelabs" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Codelabs</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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/https://firebase.google.com/docs/ml/train-object-detector" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Train object detection 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>Detect objects with your models</span></div><ul class="devsite-nav-section"><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/ml/ios/detect-objects-with-automl" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>iOS</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/https://firebase.google.com/docs/ml/android/detect-objects-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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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>Release & Monitor</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/20210127075900/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/20210127075900/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/20210127075900/https://firebase.google.com/docs/crashlytics/start-using-analytics" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Get metrics with Google Analytics</span></a></li><li class="devsite-nav-item"><a href="/web/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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"><a href="/web/20210127075900/https://firebase.google.com/docs/crashlytics/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>From Fabric to Firebase</span></div></li><li class="devsite-nav-item"><a href="/web/20210127075900/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/20210127075900/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/20210127075900/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></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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/https://firebase.google.com/docs/perf-mon/troubleshooting" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Troubleshooting & FAQ</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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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 devsite-nav-new"><a href="/web/20210127075900/https://firebase.google.com/docs/test-lab/usage-quotas-pricing" class="devsite-nav-title"><span class="devsite-nav-text" tooltip>Usage, quotas, & 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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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>Engage</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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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/20210127075900/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> <ul class="devsite-nav-list" menu="Products" aria-label="Side menu" hidden> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/products-build" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Build" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="build"> <span class="devsite-nav-text" tooltip> Build </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/products-release" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Release & Monitor" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="release&Monitor"> <span class="devsite-nav-text" tooltip> Release & Monitor </span> </a> </li> <li class="devsite-nav-item"> <a href="/web/20210127075900/https://firebase.google.com/products-engage" class="devsite-nav-title gc-analytics-event " data-category="Site-Wide Custom Events" data-label="Responsive Tab: Engage" track-type="navMenu" track-metadata-eventdetail="globalMenu" track-metadata-position="nav" track-name="engage"> <span class="devsite-nav-text" tooltip> Engage </span> </a> </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"><style> /* Styles inlined from /styles/docs.css */ .center { text-align: center } /* Used in AdMob code examples */ .oldcode { opacity: .40; /* IE 8 */ 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track-name="sendFeedbackLink" track-metadata-position="header" project-feedback-url="https://firebase.google.com/support/contact/bugs-features/" project-icon="https://firebase.google.com/_static/firebase/images/logo.png" project-support-url="https://firebase.google.com/support/" feedback-type="star-rating"> <button> Send feedback </button> </devsite-feedback> <h1 class="devsite-page-title">Transactions and batched writes</h1> <devsite-toc class="devsite-nav" devsite-toc-embedded> </devsite-toc> <div class="devsite-article-body clearfix "> <div class="video-wrapper"> <iframe class="devsite-embedded-youtube-video" data-video-id="dOVSr0OsAoU" data-autohide="1" data-showinfo="0" frameborder="0" allowfullscreen> </iframe> </div> <p>Cloud Firestore supports atomic operations for reading and writing data. In a set of atomic operations, either all of the operations succeed, or none of them are applied. There are two types of atomic operations in Cloud Firestore:</p> <ul> <li><strong>Transactions</strong>: a <a href="#transactions">transaction</a> is a set of read and write operations on one or more documents.</li> <li><strong>Batched Writes</strong>: a <a href="#batched-writes">batched write</a> is a set of write operations on one or more documents.</li> </ul> <p>Each transaction or batch of writes can write to a maximum of 500 documents. For additional limits related to writes, see <a href="https://web.archive.org/web/20210127075900/https://firebase.google.com/docs/firestore/quotas#writes_and_transactions">Quotas and Limits</a>.</p> <h2 id="transactions" data-text="Updating data with transactions">Updating data with transactions</h2> <p>Using the Cloud Firestore client libraries, you can group multiple operations into a single transaction. Transactions are useful when you want to update a field's value based on its current value, or the value of some other field.</p> <p>A transaction consists of any number of <code translate="no" dir="ltr">get()</code> operations followed by any number of write operations such as <code translate="no" dir="ltr">set()</code>, <code translate="no" dir="ltr">update()</code>, or <code translate="no" dir="ltr">delete()</code>. In the case of a concurrent edit, Cloud Firestore runs the entire transaction again. For example, if a transaction reads documents and another client modifies any of those documents, Cloud Firestore retries the transaction. This feature ensures that the transaction runs on up-to-date and consistent data.</p> <p>Transactions never partially apply writes. All writes execute at the end of a successful transaction.</p> <p>When using transactions, note that:</p> <ul> <li>Read operations must come before write operations.</li> <li>A function calling a transaction (transaction function) might run more than once if a concurrent edit affects a document that the transaction reads.</li> <li>Transaction functions should not directly modify application state.</li> <li>Transactions will fail when the client is offline.</li> </ul> <p>The following example shows how to create and run a transaction:</p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="web" data-text="Web">Web</h5> <pre class="prettyprint lang-js" translate="no" dir="ltr" data-code-snippet="true" data-github-path="firebase/snippets-web/firestore/test.firestore.js" data-region-tag="transaction">// Create a reference to the SF doc. var sfDocRef = db.collection("cities").doc("SF"); // Uncomment to initialize the doc. // sfDocRef.set({ population: 0 }); return db.runTransaction(function(transaction) { // This code may get re-run multiple times if there are conflicts. return transaction.get(sfDocRef).then(function(sfDoc) { if (!sfDoc.exists) { throw "Document does not exist!"; } // Add one person to the city population. // Note: this could be done without a transaction // by updating the population using FieldValue.increment() var newPopulation = sfDoc.data().population + 1; transaction.update(sfDocRef, { population: newPopulation }); }); }).then(function() { console.log("Transaction successfully committed!"); }).catch(function(error) { console.log("Transaction failed: ", error); });<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-web/blob/d01cdd5bb99621cf790b30505f1a2a9fec744584/firestore/test.firestore.js#L525-L548" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-web/firestore/test.firestore.js#transaction">test.firestore.js</a></div></pre> </section> <section> <h5 id="swift" data-text="Swift">Swift</h5> <pre class="prettyprint" translate="no" dir="ltr"> let sfReference = db.collection("cities").document("SF") db.runTransaction({ (transaction, errorPointer) -> Any? in let sfDocument: DocumentSnapshot do { try sfDocument = transaction.getDocument(sfReference) } catch let fetchError as NSError { errorPointer?.pointee = fetchError return nil } guard let oldPopulation = sfDocument.data()?["population"] as? Int else { let error = NSError( domain: "AppErrorDomain", code: -1, userInfo: [ NSLocalizedDescriptionKey: "Unable to retrieve population from snapshot \(sfDocument)" ] ) errorPointer?.pointee = error return nil } // Note: this could be done without a transaction // by updating the population using FieldValue.increment() transaction.updateData(["population": oldPopulation + 1], forDocument: sfReference) return nil }) { (object, error) in if let error = error { print("Transaction failed: \(error)") } else { print("Transaction successfully committed!") } }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-ios/blob/8cf680bc095d6e3bdbe273ce94511f1cd88b6e7b/firestore/swift/firestore-smoketest/ViewController.swift#L522-L555" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-ios/firestore/swift/firestore-smoketest/ViewController.swift#simple_transaction" data-code-snippet="true" data-github-path="firebase/snippets-ios/firestore/swift/firestore-smoketest/ViewController.swift" data-region-tag="simple_transaction">ViewController.swift</a></div> </pre> </section> <section> <h5 id="objective-c" data-text="Objective-C">Objective-C</h5> <pre class="prettyprint" translate="no" dir="ltr"> FIRDocumentReference *sfReference = [[self.db collectionWithPath:@"cities"] documentWithPath:@"SF"]; [self.db runTransactionWithBlock:^id (FIRTransaction *transaction, NSError **errorPointer) { FIRDocumentSnapshot *sfDocument = [transaction getDocument:sfReference error:errorPointer]; if (*errorPointer != nil) { return nil; } if (![sfDocument.data[@"population"] isKindOfClass:[NSNumber class]]) { *errorPointer = [NSError errorWithDomain:@"AppErrorDomain" code:-1 userInfo:@{ NSLocalizedDescriptionKey: @"Unable to retreive population from snapshot" }]; return nil; } NSInteger oldPopulation = [sfDocument.data[@"population"] integerValue]; // Note: this could be done without a transaction // by updating the population using FieldValue.increment() [transaction updateData:@{ @"population": @(oldPopulation + 1) } forDocument:sfReference]; return nil; } completion:^(id result, NSError *error) { if (error != nil) { NSLog(@"Transaction failed: %@", error); } else { NSLog(@"Transaction successfully committed!"); } }];<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-ios/blob/8cf680bc095d6e3bdbe273ce94511f1cd88b6e7b/firestore/objc/firestore-smoketest-objc/ViewController.m#L461-L486" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-ios/firestore/objc/firestore-smoketest-objc/ViewController.m#simple_transaction" data-code-snippet="true" data-github-path="firebase/snippets-ios/firestore/objc/firestore-smoketest-objc/ViewController.m" data-region-tag="simple_transaction">ViewController.m</a></div> </pre> </section> <section> <h3 id="java" data-text="Java"><span class="two-line-tab"><span tab-label="Android">Java</span></span></h3> <pre class="prettyprint" translate="no" dir="ltr"> final DocumentReference sfDocRef = db.collection("cities").document("SF"); db.runTransaction(new Transaction.Function<Void>() { @Override public Void apply(Transaction transaction) throws FirebaseFirestoreException { DocumentSnapshot snapshot = transaction.get(sfDocRef); // Note: this could be done without a transaction // by updating the population using FieldValue.increment() double newPopulation = snapshot.getDouble("population") + 1; transaction.update(sfDocRef, "population", newPopulation); // Success return null; } }).addOnSuccessListener(new OnSuccessListener<Void>() { @Override public void onSuccess(Void aVoid) { Log.d(TAG, "Transaction success!"); } }) .addOnFailureListener(new OnFailureListener() { @Override public void onFailure(@NonNull Exception e) { Log.w(TAG, "Transaction failure.", e); } });<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-android/blob/3cdf635260fbc295cfd4649df1bbf23bea8f5d7c/firestore/app/src/main/java/com/google/example/firestore/DocSnippets.java#L527-L553" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-android/firestore/app/src/main/java/com/google/example/firestore/DocSnippets.java#transactions" data-code-snippet="true" data-github-path="firebase/snippets-android/firestore/app/src/main/java/com/google/example/firestore/DocSnippets.java" data-region-tag="transactions">DocSnippets.java</a></div> </pre> </section> <section> <h3 id="kotlin+ktx" data-text="Kotlin+KTX"><span class="two-line-tab"><span tab-label="Android">Kotlin+KTX</span></span></h3> <pre class="prettyprint lang-kotlin" translate="no" dir="ltr"> val sfDocRef = db.collection("cities").document("SF") db.runTransaction { transaction -> val snapshot = transaction.get(sfDocRef) // Note: this could be done without a transaction // by updating the population using FieldValue.increment() val newPopulation = snapshot.getDouble("population")!! + 1 transaction.update(sfDocRef, "population", newPopulation) // Success null }.addOnSuccessListener { Log.d(TAG, "Transaction success!") } .addOnFailureListener { e -> Log.w(TAG, "Transaction failure.", e) }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-android/blob/3cdf635260fbc295cfd4649df1bbf23bea8f5d7c/firestore/app/src/main/java/com/google/example/firestore/kotlin/DocSnippets.kt#L400-L413" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-android/firestore/app/src/main/java/com/google/example/firestore/kotlin/DocSnippets.kt#transactions" data-code-snippet="true" data-github-path="firebase/snippets-android/firestore/app/src/main/java/com/google/example/firestore/kotlin/DocSnippets.kt" data-region-tag="transactions">DocSnippets.kt</a></div> </pre> </section> <section> <h5 id="java_1" data-text="Java">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Initialize doc final DocumentReference docRef = db.collection("cities").document("SF"); City city = new City("SF"); city.setCountry("USA"); city.setPopulation(860000L); docRef.set(city).get(); // run an asynchronous transaction ApiFuture<Void> futureTransaction = db.runTransaction(transaction -> { // retrieve document and increment population field DocumentSnapshot snapshot = transaction.get(docRef).get(); long oldPopulation = snapshot.getLong("population"); transaction.update(docRef, "population", oldPopulation + 1); return null; }); // block on transaction operation using transaction.get()<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/googleapis/java-firestore/blob/18879321123e74dc6763cb355a4d14a7d2f18b20/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java#L368-L385" class="gc-analytics-event" data-category="github_link" data-label="googleapis/java-firestore/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java#fs_run_simple_transaction" data-code-snippet="true" data-github-path="googleapis/java-firestore/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java" data-region-tag="fs_run_simple_transaction">ManageDataSnippets.java</a></div> </pre> </section> <section> <h5 id="python" data-text="Python">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> transaction = db.transaction() city_ref = db.collection(u'cities').document(u'SF') @firestore.transactional def update_in_transaction(transaction, city_ref): snapshot = city_ref.get(transaction=transaction) transaction.update(city_ref, { u'population': snapshot.get(u'population') + 1 }) update_in_transaction(transaction, city_ref)<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/GoogleCloudPlatform/python-docs-samples/blob/f604c2451f08bb0d099e2fa99bbf18299df308e6/firestore/cloud-client/snippets.py#L458-L470" class="gc-analytics-event" data-category="github_link" data-label="GoogleCloudPlatform/python-docs-samples/firestore/cloud-client/snippets.py#update_data_transaction" data-code-snippet="true" data-github-path="GoogleCloudPlatform/python-docs-samples/firestore/cloud-client/snippets.py" data-region-tag="update_data_transaction">snippets.py</a></div> </pre> </section> <section> <h5 id="c++" data-text="C++">C++</h5> <pre class="prettyprint" translate="no" dir="ltr"> DocumentReference sf_doc_ref = db->Collection("cities").Document("SF"); db->RunTransaction([sf_doc_ref](Transaction& transaction, std::string& out_error_message) -> Error { Error error = Error::kErrorOk; DocumentSnapshot snapshot = transaction.Get(sf_doc_ref, &error, &out_error_message); // Note: this could be done without a transaction by updating the // population using FieldValue::Increment(). std::int64_t new_population = snapshot.Get("population").integer_value() + 1; transaction.Update( sf_doc_ref, {{"population", FieldValue::Integer(new_population)}}); return Error::kErrorOk; }).OnCompletion([](const Future<void>& future) { if (future.error() == Error::kErrorOk) { std::cout << "Transaction success!\n"; } else { std::cout << "Transaction failure: " << future.error_message() << '\n'; } });<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-cpp/blob/7c0ddc1923c85b025877a9186e46eac74c2a9ba5/firestore/android/FirestoreSnippetsCpp/app/src/main/cpp/snippets.cpp#L352-L375" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-cpp/firestore/android/FirestoreSnippetsCpp/app/src/main/cpp/snippets.cpp#simple_transaction" data-code-snippet="true" data-github-path="firebase/snippets-cpp/firestore/android/FirestoreSnippetsCpp/app/src/main/cpp/snippets.cpp" data-region-tag="simple_transaction">snippets.cpp</a></div> </pre> </section> <section> <h5 id="node.js" data-text="Node.js">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Initialize document const cityRef = db.collection('cities').doc('SF'); await cityRef.set({ name: 'San Francisco', state: 'CA', country: 'USA', capital: false, population: 860000 }); try { await db.runTransaction(async (t) => { const doc = await t.get(cityRef); // Add one person to the city population. // Note: this could be done without a transaction // by updating the population using FieldValue.increment() const newPopulation = doc.data().population + 1; t.update(cityRef, {population: newPopulation}); }); console.log('Transaction success!'); } catch (e) { console.log('Transaction failure:', e); }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-node/blob/8985ddbfeb7320108b85eb1fa8852d807d9d79de/firestore/main/index.js#L391-L417" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-node/firestore/main/index.js#transaction" data-code-snippet="true" data-github-path="firebase/snippets-node/firestore/main/index.js" data-region-tag="transaction">index.js</a></div> </pre> </section> <section> <h5 id="go" data-text="Go">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.Collection("cities").Doc("SF") err := client.RunTransaction(ctx, func(ctx context.Context, tx *firestore.Transaction) error { doc, err := tx.Get(ref) // tx.Get, NOT ref.Get! if err != nil { return err } pop, err := doc.DataAt("population") if err != nil { return err } return tx.Set(ref, map[string]interface{}{ "population": pop.(int64) + 1, }, firestore.MergeAll) }) if err != nil { // Handle any errors appropriately in this section. log.Printf("An error has occurred: %s", err) }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/GoogleCloudPlatform/golang-samples/blob/c789b285febcca601ed10db769fd59e2e4bb4f60/firestore/firestore_snippets/save.go#L347-L366" class="gc-analytics-event" data-category="github_link" data-label="GoogleCloudPlatform/golang-samples/firestore/firestore_snippets/save.go#fs_run_simple_transaction" data-code-snippet="true" data-github-path="GoogleCloudPlatform/golang-samples/firestore/firestore_snippets/save.go" data-region-tag="fs_run_simple_transaction">save.go</a></div> </pre> </section> <section> <h5 id="php" data-text="PHP">PHP</h5> <pre class="prettyprint" translate="no" dir="ltr"> $cityRef = $db->collection('cities')->document('SF'); $db->runTransaction(function (Transaction $transaction) use ($cityRef) { $snapshot = $transaction->snapshot($cityRef); $newPopulation = $snapshot['population'] + 1; $transaction->update($cityRef, [ ['path' => 'population', 'value' => $newPopulation] ]); });<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/GoogleCloudPlatform/php-docs-samples/blob/906d56f233954dfcaa47237d491851234608257c/firestore/src/run_simple_transaction.php#L42-L49" class="gc-analytics-event" data-category="github_link" data-label="GoogleCloudPlatform/php-docs-samples/firestore/src/run_simple_transaction.php#fs_run_simple_transaction" data-code-snippet="true" data-github-path="GoogleCloudPlatform/php-docs-samples/firestore/src/run_simple_transaction.php" data-region-tag="fs_run_simple_transaction">run_simple_transaction.php</a></div> </pre> </section> <section> <h5 id="unity" data-text="Unity">Unity</h5> <pre class="prettyprint" translate="no" dir="ltr"> DocumentReference cityRef = db.Collection("cities").Document("SF"); db.RunTransactionAsync(transaction => { return transaction.GetSnapshotAsync(cityRef).ContinueWith((snapshotTask) => { DocumentSnapshot snapshot = snapshotTask.Result; long newPopulation = snapshot.GetValue<long>("Population") + 1; Dictionary<string, object> updates = new Dictionary<string, object> { { "Population", newPopulation} }; transaction.Update(cityRef, updates); }); }); </pre> </section> <section> <h5 id="c" data-text="C#">C#</h5> <pre class="prettyprint" translate="no" dir="ltr"> DocumentReference cityRef = db.Collection("cities").Document("SF"); await db.RunTransactionAsync(async transaction => { DocumentSnapshot snapshot = await transaction.GetSnapshotAsync(cityRef); long newPopulation = snapshot.GetValue<long>("Population") + 1; Dictionary<string, object> updates = new Dictionary<string, object> { { "Population", newPopulation} }; transaction.Update(cityRef, updates); });<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/GoogleCloudPlatform/dotnet-docs-samples/blob/95ab04d6b87ffa53031f71d61045f7261b157cd5/firestore/api/TransactionsAndBatchedWrites/Program.cs#L38-L48" class="gc-analytics-event" data-category="github_link" data-label="GoogleCloudPlatform/dotnet-docs-samples/firestore/api/TransactionsAndBatchedWrites/Program.cs#fs_run_simple_transaction" data-code-snippet="true" data-github-path="GoogleCloudPlatform/dotnet-docs-samples/firestore/api/TransactionsAndBatchedWrites/Program.cs" data-region-tag="fs_run_simple_transaction">Program.cs</a></div> </pre> </section> <section> <h5 id="ruby" data-text="Ruby">Ruby</h5> <pre class="prettyprint" translate="no" dir="ltr"> def run_simple_transaction project_id:, collection_path: "cities" # project_id = "Your Google Cloud Project ID" # collection_path = "cities" firestore = Google::Cloud::Firestore.new project_id: project_id city_ref = firestore.doc "#{collection_path}/SF" firestore.transaction do |tx| new_population = tx.get(city_ref).data[:population] + 1 puts "New population is #{new_population}." tx.update city_ref, population: new_population end puts "Ran a simple transaction to update the population field in the SF document in the cities collection." end<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/googleapis/google-cloud-ruby/blob/146b9fbd185ff9018f6d3bca573cf8e875db3ab0/google-cloud-firestore/samples/transactions_and_batched_writes.rb#L18-L32" class="gc-analytics-event" data-category="github_link" data-label="googleapis/google-cloud-ruby/google-cloud-firestore/samples/transactions_and_batched_writes.rb#fs_run_simple_transaction" data-code-snippet="true" data-github-path="googleapis/google-cloud-ruby/google-cloud-firestore/samples/transactions_and_batched_writes.rb" data-region-tag="fs_run_simple_transaction">transactions_and_batched_writes.rb</a></div> </pre> </section> </div> <h3 id="passing_information_out_of_transactions" data-text="Passing information out of transactions">Passing information out of transactions</h3> <p>Do not modify application state inside of your transaction functions. Doing so will introduce concurrency issues, because transaction functions can run multiple times and are not guaranteed to run on the UI thread. Instead, pass information you need out of your transaction functions. The following example builds on the previous example to show how to pass information out of a transaction:</p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="web_1" data-text="Web">Web</h5> <pre class="prettyprint lang-js" translate="no" dir="ltr" data-code-snippet="true" data-github-path="firebase/snippets-web/firestore/test.firestore.js" data-region-tag="transaction_promise">// Create a reference to the SF doc. var sfDocRef = db.collection("cities").doc("SF"); db.runTransaction(function(transaction) { return transaction.get(sfDocRef).then(function(sfDoc) { if (!sfDoc.exists) { throw "Document does not exist!"; } var newPopulation = sfDoc.data().population + 1; if (newPopulation <= 1000000) { transaction.update(sfDocRef, { population: newPopulation }); return newPopulation; } else { return Promise.reject("Sorry! Population is too big."); } }); }).then(function(newPopulation) { console.log("Population increased to ", newPopulation); }).catch(function(err) { // This will be an "population is too big" error. console.error(err); });<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-web/blob/d01cdd5bb99621cf790b30505f1a2a9fec744584/firestore/test.firestore.js#L555-L577" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-web/firestore/test.firestore.js#transaction_promise">test.firestore.js</a></div></pre> </section> <section> <h5 id="swift_1" data-text="Swift">Swift</h5> <pre class="prettyprint" translate="no" dir="ltr"> let sfReference = db.collection("cities").document("SF") db.runTransaction({ (transaction, errorPointer) -> Any? in let sfDocument: DocumentSnapshot do { try sfDocument = transaction.getDocument(sfReference) } catch let fetchError as NSError { errorPointer?.pointee = fetchError return nil } guard let oldPopulation = sfDocument.data()?["population"] as? Int else { let error = NSError( domain: "AppErrorDomain", code: -1, userInfo: [ NSLocalizedDescriptionKey: "Unable to retrieve population from snapshot \(sfDocument)" ] ) errorPointer?.pointee = error return nil } // Note: this could be done without a transaction // by updating the population using FieldValue.increment() let newPopulation = oldPopulation + 1 guard newPopulation <= 1000000 else { let error = NSError( domain: "AppErrorDomain", code: -2, userInfo: [NSLocalizedDescriptionKey: "Population \(newPopulation) too big"] ) errorPointer?.pointee = error return nil } transaction.updateData(["population": newPopulation], forDocument: sfReference) return newPopulation }) { (object, error) in if let error = error { print("Error updating population: \(error)") } else { print("Population increased to \(object!)") } }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-ios/blob/8cf680bc095d6e3bdbe273ce94511f1cd88b6e7b/firestore/swift/firestore-smoketest/ViewController.swift#L561-L605" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-ios/firestore/swift/firestore-smoketest/ViewController.swift#transaction" data-code-snippet="true" data-github-path="firebase/snippets-ios/firestore/swift/firestore-smoketest/ViewController.swift" data-region-tag="transaction">ViewController.swift</a></div> </pre> </section> <section> <h5 id="objective-c_1" data-text="Objective-C">Objective-C</h5> <pre class="prettyprint" translate="no" dir="ltr"> FIRDocumentReference *sfReference = [[self.db collectionWithPath:@"cities"] documentWithPath:@"SF"]; [self.db runTransactionWithBlock:^id (FIRTransaction *transaction, NSError **errorPointer) { FIRDocumentSnapshot *sfDocument = [transaction getDocument:sfReference error:errorPointer]; if (*errorPointer != nil) { return nil; } if (![sfDocument.data[@"population"] isKindOfClass:[NSNumber class]]) { *errorPointer = [NSError errorWithDomain:@"AppErrorDomain" code:-1 userInfo:@{ NSLocalizedDescriptionKey: @"Unable to retreive population from snapshot" }]; return nil; } NSInteger population = [sfDocument.data[@"population"] integerValue]; population++; if (population >= 1000000) { *errorPointer = [NSError errorWithDomain:@"AppErrorDomain" code:-2 userInfo:@{ NSLocalizedDescriptionKey: @"Population too big" }]; return @(population); } [transaction updateData:@{ @"population": @(population) } forDocument:sfReference]; return nil; } completion:^(id result, NSError *error) { if (error != nil) { NSLog(@"Transaction failed: %@", error); } else { NSLog(@"Population increased to %@", result); } }];<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-ios/blob/8cf680bc095d6e3bdbe273ce94511f1cd88b6e7b/firestore/objc/firestore-smoketest-objc/ViewController.m#L492-L523" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-ios/firestore/objc/firestore-smoketest-objc/ViewController.m#transaction" data-code-snippet="true" data-github-path="firebase/snippets-ios/firestore/objc/firestore-smoketest-objc/ViewController.m" data-region-tag="transaction">ViewController.m</a></div> </pre> </section> <section> <h3 id="java_2" data-text="Java"><span class="two-line-tab"><span tab-label="Android">Java</span></span></h3> <pre class="prettyprint" translate="no" dir="ltr"> final DocumentReference sfDocRef = db.collection("cities").document("SF"); db.runTransaction(new Transaction.Function<Double>() { @Override public Double apply(Transaction transaction) throws FirebaseFirestoreException { DocumentSnapshot snapshot = transaction.get(sfDocRef); double newPopulation = snapshot.getDouble("population") + 1; if (newPopulation <= 1000000) { transaction.update(sfDocRef, "population", newPopulation); return newPopulation; } else { throw new FirebaseFirestoreException("Population too high", FirebaseFirestoreException.Code.ABORTED); } } }).addOnSuccessListener(new OnSuccessListener<Double>() { @Override public void onSuccess(Double result) { Log.d(TAG, "Transaction success: " + result); } }) .addOnFailureListener(new OnFailureListener() { @Override public void onFailure(@NonNull Exception e) { Log.w(TAG, "Transaction failure.", e); } });<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-android/blob/3cdf635260fbc295cfd4649df1bbf23bea8f5d7c/firestore/app/src/main/java/com/google/example/firestore/DocSnippets.java#L559-L585" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-android/firestore/app/src/main/java/com/google/example/firestore/DocSnippets.java#transaction_with_result" data-code-snippet="true" data-github-path="firebase/snippets-android/firestore/app/src/main/java/com/google/example/firestore/DocSnippets.java" data-region-tag="transaction_with_result">DocSnippets.java</a></div> </pre> </section> <section> <h3 id="kotlin+ktx_1" data-text="Kotlin+KTX"><span class="two-line-tab"><span tab-label="Android">Kotlin+KTX</span></span></h3> <pre class="prettyprint lang-kotlin" translate="no" dir="ltr"> val sfDocRef = db.collection("cities").document("SF") db.runTransaction { transaction -> val snapshot = transaction.get(sfDocRef) val newPopulation = snapshot.getDouble("population")!! + 1 if (newPopulation <= 1000000) { transaction.update(sfDocRef, "population", newPopulation) newPopulation } else { throw FirebaseFirestoreException("Population too high", FirebaseFirestoreException.Code.ABORTED) } }.addOnSuccessListener { result -> Log.d(TAG, "Transaction success: $result") }.addOnFailureListener { e -> Log.w(TAG, "Transaction failure.", e) }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-android/blob/3cdf635260fbc295cfd4649df1bbf23bea8f5d7c/firestore/app/src/main/java/com/google/example/firestore/kotlin/DocSnippets.kt#L419-L435" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-android/firestore/app/src/main/java/com/google/example/firestore/kotlin/DocSnippets.kt#transaction_with_result" data-code-snippet="true" data-github-path="firebase/snippets-android/firestore/app/src/main/java/com/google/example/firestore/kotlin/DocSnippets.kt" data-region-tag="transaction_with_result">DocSnippets.kt</a></div> </pre> </section> <section> <h5 id="java_3" data-text="Java">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> final DocumentReference docRef = db.collection("cities").document("SF"); ApiFuture<String> futureTransaction = db.runTransaction(transaction -> { DocumentSnapshot snapshot = transaction.get(docRef).get(); Long newPopulation = snapshot.getLong("population") + 1; // conditionally update based on current population if (newPopulation <= 1000000L) { transaction.update(docRef, "population", newPopulation); return "Population increased to " + newPopulation; } else { throw new Exception("Sorry! Population is too big."); } }); // Print information retrieved from transaction System.out.println(futureTransaction.get());<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/googleapis/java-firestore/blob/18879321123e74dc6763cb355a4d14a7d2f18b20/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java#L402-L417" class="gc-analytics-event" data-category="github_link" data-label="googleapis/java-firestore/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java#fs_return_info_transaction" data-code-snippet="true" data-github-path="googleapis/java-firestore/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java" data-region-tag="fs_return_info_transaction">ManageDataSnippets.java</a></div> </pre> </section> <section> <h5 id="python_1" data-text="Python">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> transaction = db.transaction() city_ref = db.collection(u'cities').document(u'SF') @firestore.transactional def update_in_transaction(transaction, city_ref): snapshot = city_ref.get(transaction=transaction) new_population = snapshot.get(u'population') + 1 if new_population < 1000000: transaction.update(city_ref, { u'population': new_population }) return True else: return False result = update_in_transaction(transaction, city_ref) if result: print(u'Population updated') else: print(u'Sorry! Population is too big.')<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/GoogleCloudPlatform/python-docs-samples/blob/f604c2451f08bb0d099e2fa99bbf18299df308e6/firestore/cloud-client/snippets.py#L477-L499" class="gc-analytics-event" data-category="github_link" data-label="GoogleCloudPlatform/python-docs-samples/firestore/cloud-client/snippets.py#update_data_transaction_result" data-code-snippet="true" data-github-path="GoogleCloudPlatform/python-docs-samples/firestore/cloud-client/snippets.py" data-region-tag="update_data_transaction_result">snippets.py</a></div> </pre> </section> <section> <h5 id="c++_1" data-text="C++">C++</h5> <pre class="prettyprint" translate="no" dir="ltr"> // This is not yet supported. </pre> </section> <section> <h5 id="node.js_1" data-text="Node.js">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> const cityRef = db.collection('cities').doc('SF'); try { const res = await db.runTransaction(async t => { const doc = await t.get(cityRef); const newPopulation = doc.data().population + 1; if (newPopulation <= 1000000) { await t.update(cityRef, { population: newPopulation }); return `Population increased to ${newPopulation}`; } else { throw 'Sorry! Population is too big.'; } }); console.log('Transaction success', res); } catch (e) { console.log('Transaction failure:', e); }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-node/blob/8985ddbfeb7320108b85eb1fa8852d807d9d79de/firestore/main/index.js#L423-L440" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-node/firestore/main/index.js#transaction_with_result" data-code-snippet="true" data-github-path="firebase/snippets-node/firestore/main/index.js" data-region-tag="transaction_with_result">index.js</a></div> </pre> </section> <section> <h5 id="go_1" data-text="Go">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> ref := client.Collection("cities").Doc("SF") err := client.RunTransaction(ctx, func(ctx context.Context, tx *firestore.Transaction) error { doc, err := tx.Get(ref) if err != nil { return err } pop, err := doc.DataAt("population") if err != nil { return err } newpop := pop.(int64) + 1 if newpop <= 1000000 { return tx.Set(ref, map[string]interface{}{ "population": pop.(int64) + 1, }, firestore.MergeAll) } return errors.New("population is too big") }) if err != nil { // Handle any errors in an appropriate way, such as returning them. log.Printf("An error has occurred: %s", err) }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/GoogleCloudPlatform/golang-samples/blob/c789b285febcca601ed10db769fd59e2e4bb4f60/firestore/firestore_snippets/save.go#L373-L396" class="gc-analytics-event" data-category="github_link" data-label="GoogleCloudPlatform/golang-samples/firestore/firestore_snippets/save.go#fs_return_info_transaction" data-code-snippet="true" data-github-path="GoogleCloudPlatform/golang-samples/firestore/firestore_snippets/save.go" data-region-tag="fs_return_info_transaction">save.go</a></div> </pre> </section> <section> <h5 id="php_1" data-text="PHP">PHP</h5> <pre class="prettyprint" translate="no" dir="ltr"> $cityRef = $db->collection('cities')->document('SF'); $transactionResult = $db->runTransaction(function (Transaction $transaction) use ($cityRef) { $snapshot = $transaction->snapshot($cityRef); $newPopulation = $snapshot['population'] + 1; if ($newPopulation <= 1000000) { $transaction->update($cityRef, [ ['path' => 'population', 'value' => $newPopulation] ]); return true; } else { return false; } }); if ($transactionResult) { printf('Population updated successfully.' . PHP_EOL); } else { printf('Sorry! Population is too big.' . PHP_EOL); }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/GoogleCloudPlatform/php-docs-samples/blob/906d56f233954dfcaa47237d491851234608257c/firestore/src/return_info_transaction.php#L42-L60" class="gc-analytics-event" data-category="github_link" data-label="GoogleCloudPlatform/php-docs-samples/firestore/src/return_info_transaction.php#fs_return_info_transaction" data-code-snippet="true" data-github-path="GoogleCloudPlatform/php-docs-samples/firestore/src/return_info_transaction.php" data-region-tag="fs_return_info_transaction">return_info_transaction.php</a></div> </pre> </section> <section> <h5 id="unity_1" data-text="Unity">Unity</h5> <pre class="prettyprint" translate="no" dir="ltr"> DocumentReference cityRef = db.Collection("cities").Document("SF"); db.RunTransactionAsync(transaction => { return transaction.GetSnapshotAsync(cityRef).ContinueWith((task) => { long newPopulation = task.Result.GetValue<long>("Population") + 1; if (newPopulation <= 1000000) { Dictionary<string, object> updates = new Dictionary<string, object> { { "Population", newPopulation} }; transaction.Update(cityRef, updates); return true; } else { return false; } }); }).ContinueWith((transactionResultTask) => { if (transactionResultTask.Result) { Console.WriteLine("Population updated successfully."); } else { Console.WriteLine("Sorry! Population is too big."); } }); </pre> </section> <section> <h5 id="c_1" data-text="C#">C#</h5> <pre class="prettyprint" translate="no" dir="ltr"> DocumentReference cityRef = db.Collection("cities").Document("SF"); bool transactionResult = await db.RunTransactionAsync(async transaction => { DocumentSnapshot snapshot = await transaction.GetSnapshotAsync(cityRef); long newPopulation = snapshot.GetValue<long>("Population") + 1; if (newPopulation <= 1000000) { Dictionary<string, object> updates = new Dictionary<string, object> { { "Population", newPopulation} }; transaction.Update(cityRef, updates); return true; } else { return false; } }); if (transactionResult) { Console.WriteLine("Population updated successfully."); } else { Console.WriteLine("Sorry! Population is too big."); }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/GoogleCloudPlatform/dotnet-docs-samples/blob/95ab04d6b87ffa53031f71d61045f7261b157cd5/firestore/api/TransactionsAndBatchedWrites/Program.cs#L57-L84" class="gc-analytics-event" data-category="github_link" data-label="GoogleCloudPlatform/dotnet-docs-samples/firestore/api/TransactionsAndBatchedWrites/Program.cs#fs_return_info_transaction" data-code-snippet="true" data-github-path="GoogleCloudPlatform/dotnet-docs-samples/firestore/api/TransactionsAndBatchedWrites/Program.cs" data-region-tag="fs_return_info_transaction">Program.cs</a></div> </pre> </section> <section> <h5 id="ruby_1" data-text="Ruby">Ruby</h5> <pre class="prettyprint" translate="no" dir="ltr"> def return_info_transaction project_id:, collection_path: "cities" # project_id = "Your Google Cloud Project ID" # collection_path = "cities" firestore = Google::Cloud::Firestore.new project_id: project_id city_ref = firestore.doc "#{collection_path}/SF" updated = firestore.transaction do |tx| new_population = tx.get(city_ref).data[:population] + 1 if new_population < 1_000_000 tx.update city_ref, population: new_population true else false end end if updated puts "Population updated!" else puts "Sorry! Population is too big." end end<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/googleapis/google-cloud-ruby/blob/146b9fbd185ff9018f6d3bca573cf8e875db3ab0/google-cloud-firestore/samples/transactions_and_batched_writes.rb#L36-L59" class="gc-analytics-event" data-category="github_link" data-label="googleapis/google-cloud-ruby/google-cloud-firestore/samples/transactions_and_batched_writes.rb#fs_return_info_transaction" data-code-snippet="true" data-github-path="googleapis/google-cloud-ruby/google-cloud-firestore/samples/transactions_and_batched_writes.rb" data-region-tag="fs_return_info_transaction">transactions_and_batched_writes.rb</a></div> </pre> </section> </div> <h3 id="transaction_failure" data-text="Transaction failure">Transaction failure</h3> <p>A transaction can fail for the following reasons:</p> <ul> <li>The transaction contains read operations after write operations. Read operations must always come before any write operations.</li> <li>The transaction read a document that was modified outside of the transaction. In this case, the transaction automatically runs again. The transaction is retried a finite number of times.</li> <li><p>The transaction exceeded the maximum request size of 10 MiB.</p> <p>Transaction size depends on the sizes of documents and index entries modified by the transaction. For a delete operation, this includes the size of the target document and the sizes of the index entries deleted in response to the operation.</p></li> </ul> <p>A failed transaction returns an error and does not write anything to the database. You do not need to roll back the transaction; Cloud Firestore does this automatically.</p> <h2 id="batched-writes" data-text="Batched writes">Batched writes</h2> <p>If you do not need to read any documents in your operation set, you can execute multiple write operations as a single batch that contains any combination of <code translate="no" dir="ltr">set()</code>, <code translate="no" dir="ltr">update()</code>, or <code translate="no" dir="ltr">delete()</code> operations. A batch of writes completes atomically and can write to multiple documents. The following example shows how to build and commit a write batch:</p> <div class="ds-selector-tabs" data-ds-scope="lang"> <section> <h5 id="web_2" data-text="Web">Web</h5> <pre class="prettyprint lang-js" translate="no" dir="ltr" data-code-snippet="true" data-github-path="firebase/snippets-web/firestore/test.firestore.js" data-region-tag="write_batch">// Get a new write batch var batch = db.batch(); // Set the value of 'NYC' var nycRef = db.collection("cities").doc("NYC"); batch.set(nycRef, {name: "New York City"}); // Update the population of 'SF' var sfRef = db.collection("cities").doc("SF"); batch.update(sfRef, {"population": 1000000}); // Delete the city 'LA' var laRef = db.collection("cities").doc("LA"); batch.delete(laRef); // Commit the batch batch.commit().then(function () { // ... });<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-web/blob/d01cdd5bb99621cf790b30505f1a2a9fec744584/firestore/test.firestore.js#L270-L290" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-web/firestore/test.firestore.js#write_batch">test.firestore.js</a></div></pre> </section> <section> <h5 id="swift_2" data-text="Swift">Swift</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Get new write batch let batch = db.batch() // Set the value of 'NYC' let nycRef = db.collection("cities").document("NYC") batch.setData([:], forDocument: nycRef) // Update the population of 'SF' let sfRef = db.collection("cities").document("SF") batch.updateData(["population": 1000000 ], forDocument: sfRef) // Delete the city 'LA' let laRef = db.collection("cities").document("LA") batch.deleteDocument(laRef) // Commit the batch batch.commit() { err in if let err = err { print("Error writing batch \(err)") } else { print("Batch write succeeded.") } }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-ios/blob/8cf680bc095d6e3bdbe273ce94511f1cd88b6e7b/firestore/swift/firestore-smoketest/ViewController.swift#L611-L633" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-ios/firestore/swift/firestore-smoketest/ViewController.swift#write_batch" data-code-snippet="true" data-github-path="firebase/snippets-ios/firestore/swift/firestore-smoketest/ViewController.swift" data-region-tag="write_batch">ViewController.swift</a></div> </pre> </section> <section> <h5 id="objective-c_2" data-text="Objective-C">Objective-C</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Get new write batch FIRWriteBatch *batch = [self.db batch]; // Set the value of 'NYC' FIRDocumentReference *nycRef = [[self.db collectionWithPath:@"cities"] documentWithPath:@"NYC"]; [batch setData:@{} forDocument:nycRef]; // Update the population of 'SF' FIRDocumentReference *sfRef = [[self.db collectionWithPath:@"cities"] documentWithPath:@"SF"]; [batch updateData:@{ @"population": @1000000 } forDocument:sfRef]; // Delete the city 'LA' FIRDocumentReference *laRef = [[self.db collectionWithPath:@"cities"] documentWithPath:@"LA"]; [batch deleteDocument:laRef]; // Commit the batch [batch commitWithCompletion:^(NSError * _Nullable error) { if (error != nil) { NSLog(@"Error writing batch %@", error); } else { NSLog(@"Batch write succeeded."); } }];<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-ios/blob/8cf680bc095d6e3bdbe273ce94511f1cd88b6e7b/firestore/objc/firestore-smoketest-objc/ViewController.m#L529-L554" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-ios/firestore/objc/firestore-smoketest-objc/ViewController.m#write_batch" data-code-snippet="true" data-github-path="firebase/snippets-ios/firestore/objc/firestore-smoketest-objc/ViewController.m" data-region-tag="write_batch">ViewController.m</a></div> </pre> </section> <section> <h3 id="java_4" data-text="Java"><span class="two-line-tab"><span tab-label="Android">Java</span></span></h3> <pre class="prettyprint" translate="no" dir="ltr"> // Get a new write batch WriteBatch batch = db.batch(); // Set the value of 'NYC' DocumentReference nycRef = db.collection("cities").document("NYC"); batch.set(nycRef, new City()); // Update the population of 'SF' DocumentReference sfRef = db.collection("cities").document("SF"); batch.update(sfRef, "population", 1000000L); // Delete the city 'LA' DocumentReference laRef = db.collection("cities").document("LA"); batch.delete(laRef); // Commit the batch batch.commit().addOnCompleteListener(new OnCompleteListener<Void>() { @Override public void onComplete(@NonNull Task<Void> task) { // ... } });<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-android/blob/3cdf635260fbc295cfd4649df1bbf23bea8f5d7c/firestore/app/src/main/java/com/google/example/firestore/DocSnippets.java#L591-L612" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-android/firestore/app/src/main/java/com/google/example/firestore/DocSnippets.java#write_batch" data-code-snippet="true" data-github-path="firebase/snippets-android/firestore/app/src/main/java/com/google/example/firestore/DocSnippets.java" data-region-tag="write_batch">DocSnippets.java</a></div> </pre> </section> <section> <h3 id="kotlin+ktx_2" data-text="Kotlin+KTX"><span class="two-line-tab"><span tab-label="Android">Kotlin+KTX</span></span></h3> <pre class="prettyprint lang-kotlin" translate="no" dir="ltr"> val nycRef = db.collection("cities").document("NYC") val sfRef = db.collection("cities").document("SF") val laRef = db.collection("cities").document("LA") // Get a new write batch and commit all write operations db.runBatch { batch -> // Set the value of 'NYC' batch.set(nycRef, City()) // Update the population of 'SF' batch.update(sfRef, "population", 1000000L) // Delete the city 'LA' batch.delete(laRef) }.addOnCompleteListener { // ... }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-android/blob/3cdf635260fbc295cfd4649df1bbf23bea8f5d7c/firestore/app/src/main/java/com/google/example/firestore/kotlin/DocSnippets.kt#L441-L457" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-android/firestore/app/src/main/java/com/google/example/firestore/kotlin/DocSnippets.kt#write_batch" data-code-snippet="true" data-github-path="firebase/snippets-android/firestore/app/src/main/java/com/google/example/firestore/kotlin/DocSnippets.kt" data-region-tag="write_batch">DocSnippets.kt</a></div> </pre> </section> <section> <h5 id="java_5" data-text="Java">Java</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Get a new write batch WriteBatch batch = db.batch(); // Set the value of 'NYC' DocumentReference nycRef = db.collection("cities").document("NYC"); batch.set(nycRef, new City()); // Update the population of 'SF' DocumentReference sfRef = db.collection("cities").document("SF"); batch.update(sfRef, "population", 1000000L); // Delete the city 'LA' DocumentReference laRef = db.collection("cities").document("LA"); batch.delete(laRef); // asynchronously commit the batch ApiFuture<List<WriteResult>> future = batch.commit(); // ... // future.get() blocks on batch commit operation for (WriteResult result : future.get()) { System.out.println("Update time : " + result.getUpdateTime()); }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/googleapis/java-firestore/blob/18879321123e74dc6763cb355a4d14a7d2f18b20/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java#L428-L451" class="gc-analytics-event" data-category="github_link" data-label="googleapis/java-firestore/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java#fs_write_batch" data-code-snippet="true" data-github-path="googleapis/java-firestore/samples/snippets/src/main/java/com/example/firestore/snippets/ManageDataSnippets.java" data-region-tag="fs_write_batch">ManageDataSnippets.java</a></div> </pre> </section> <section> <h5 id="python_2" data-text="Python">Python</h5> <pre class="prettyprint" translate="no" dir="ltr"> batch = db.batch() # Set the data for NYC nyc_ref = db.collection(u'cities').document(u'NYC') batch.set(nyc_ref, {u'name': u'New York City'}) # Update the population for SF sf_ref = db.collection(u'cities').document(u'SF') batch.update(sf_ref, {u'population': 1000000}) # Delete DEN den_ref = db.collection(u'cities').document(u'DEN') batch.delete(den_ref) # Commit the batch batch.commit()<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/GoogleCloudPlatform/python-docs-samples/blob/f604c2451f08bb0d099e2fa99bbf18299df308e6/firestore/cloud-client/snippets.py#L506-L523" class="gc-analytics-event" data-category="github_link" data-label="GoogleCloudPlatform/python-docs-samples/firestore/cloud-client/snippets.py#update_data_batch" data-code-snippet="true" data-github-path="GoogleCloudPlatform/python-docs-samples/firestore/cloud-client/snippets.py" data-region-tag="update_data_batch">snippets.py</a></div> </pre> </section> <section> <h5 id="c++_2" data-text="C++">C++</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Get a new write batch WriteBatch batch = db->batch(); // Set the value of 'NYC' DocumentReference nyc_ref = db->Collection("cities").Document("NYC"); batch.Set(nyc_ref, {}); // Update the population of 'SF' DocumentReference sf_ref = db->Collection("cities").Document("SF"); batch.Update(sf_ref, {{"population", FieldValue::Integer(1000000)}}); // Delete the city 'LA' DocumentReference la_ref = db->Collection("cities").Document("LA"); batch.Delete(la_ref); // Commit the batch batch.Commit().OnCompletion([](const Future<void>& future) { if (future.error() == Error::kErrorOk) { std::cout << "Write batch success!\n"; } else { std::cout << "Write batch failure: " << future.error_message() << '\n'; } });<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-cpp/blob/7c0ddc1923c85b025877a9186e46eac74c2a9ba5/firestore/android/FirestoreSnippetsCpp/app/src/main/cpp/snippets.cpp#L315-L337" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-cpp/firestore/android/FirestoreSnippetsCpp/app/src/main/cpp/snippets.cpp#write_batch" data-code-snippet="true" data-github-path="firebase/snippets-cpp/firestore/android/FirestoreSnippetsCpp/app/src/main/cpp/snippets.cpp" data-region-tag="write_batch">snippets.cpp</a></div> </pre> </section> <section> <h5 id="node.js_2" data-text="Node.js">Node.js</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Get a new write batch const batch = db.batch(); // Set the value of 'NYC' const nycRef = db.collection('cities').doc('NYC'); batch.set(nycRef, {name: 'New York City'}); // Update the population of 'SF' const sfRef = db.collection('cities').doc('SF'); batch.update(sfRef, {population: 1000000}); // Delete the city 'LA' const laRef = db.collection('cities').doc('LA'); batch.delete(laRef); // Commit the batch await batch.commit();<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/firebase/snippets-node/blob/8985ddbfeb7320108b85eb1fa8852d807d9d79de/firestore/main/index.js#L448-L466" class="gc-analytics-event" data-category="github_link" data-label="firebase/snippets-node/firestore/main/index.js#update_data_batch" data-code-snippet="true" data-github-path="firebase/snippets-node/firestore/main/index.js" data-region-tag="update_data_batch">index.js</a></div> </pre> </section> <section> <h5 id="go_2" data-text="Go">Go</h5> <pre class="prettyprint" translate="no" dir="ltr"> // Get a new write batch. batch := client.Batch() // Set the value of "NYC". nycRef := client.Collection("cities").Doc("NYC") batch.Set(nycRef, map[string]interface{}{ "name": "New York City", }) // Update the population of "SF". sfRef := client.Collection("cities").Doc("SF") batch.Set(sfRef, map[string]interface{}{ "population": 1000000, }, firestore.MergeAll) // Delete the city "LA". laRef := client.Collection("cities").Doc("LA") batch.Delete(laRef) // Commit the batch. _, err := batch.Commit(ctx) if err != nil { // Handle any errors in an appropriate way, such as returning them. log.Printf("An error has occurred: %s", err) }<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/GoogleCloudPlatform/golang-samples/blob/c789b285febcca601ed10db769fd59e2e4bb4f60/firestore/firestore_snippets/save.go#L403-L429" class="gc-analytics-event" data-category="github_link" data-label="GoogleCloudPlatform/golang-samples/firestore/firestore_snippets/save.go#fs_batch_write" data-code-snippet="true" data-github-path="GoogleCloudPlatform/golang-samples/firestore/firestore_snippets/save.go" data-region-tag="fs_batch_write">save.go</a></div> </pre> </section> <section> <h5 id="php_2" data-text="PHP">PHP</h5> <pre class="prettyprint" translate="no" dir="ltr"> $batch = $db->batch(); # Set the data for NYC $nycRef = $db->collection('cities')->document('NYC'); $batch->set($nycRef, [ 'name' => 'New York City' ]); # Update the population for SF $sfRef = $db->collection('cities')->document('SF'); $batch->update($sfRef, [ ['path' => 'population', 'value' => 1000000] ]); # Delete LA $laRef = $db->collection('cities')->document('LA'); $batch->delete($laRef); # Commit the batch $batch->commit();<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/GoogleCloudPlatform/php-docs-samples/blob/906d56f233954dfcaa47237d491851234608257c/firestore/src/batch_write.php#L41-L60" class="gc-analytics-event" data-category="github_link" data-label="GoogleCloudPlatform/php-docs-samples/firestore/src/batch_write.php#fs_batch_write" data-code-snippet="true" data-github-path="GoogleCloudPlatform/php-docs-samples/firestore/src/batch_write.php" data-region-tag="fs_batch_write">batch_write.php</a></div> </pre> </section> <section> <h5 id="unity_2" data-text="Unity">Unity</h5> <pre class="prettyprint" translate="no" dir="ltr"> WriteBatch batch = db.StartBatch(); // Set the data for NYC DocumentReference nycRef = db.Collection("cities").Document("NYC"); Dictionary<string, object> nycData = new Dictionary<string, object> { { "name", "New York City" } }; batch.Set(nycRef, nycData); // Update the population for SF DocumentReference sfRef = db.Collection("cities").Document("SF"); Dictionary<string, object> updates = new Dictionary<string, object> { { "Population", 1000000} }; batch.Update(sfRef, updates); // Delete LA DocumentReference laRef = db.Collection("cities").Document("LA"); batch.Delete(laRef); // Commit the batch batch.CommitAsync(); </pre> </section> <section> <h5 id="c_2" data-text="C#">C#</h5> <pre class="prettyprint" translate="no" dir="ltr"> WriteBatch batch = db.StartBatch(); // Set the data for NYC DocumentReference nycRef = db.Collection("cities").Document("NYC"); Dictionary<string, object> nycData = new Dictionary<string, object> { { "name", "New York City" } }; batch.Set(nycRef, nycData); // Update the population for SF DocumentReference sfRef = db.Collection("cities").Document("SF"); Dictionary<string, object> updates = new Dictionary<string, object> { { "Population", 1000000} }; batch.Update(sfRef, updates); // Delete LA DocumentReference laRef = db.Collection("cities").Document("LA"); batch.Delete(laRef); // Commit the batch await batch.CommitAsync();<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/GoogleCloudPlatform/dotnet-docs-samples/blob/95ab04d6b87ffa53031f71d61045f7261b157cd5/firestore/api/TransactionsAndBatchedWrites/Program.cs#L92-L115" class="gc-analytics-event" data-category="github_link" data-label="GoogleCloudPlatform/dotnet-docs-samples/firestore/api/TransactionsAndBatchedWrites/Program.cs#fs_batch_write" data-code-snippet="true" data-github-path="GoogleCloudPlatform/dotnet-docs-samples/firestore/api/TransactionsAndBatchedWrites/Program.cs" data-region-tag="fs_batch_write">Program.cs</a></div> </pre> </section> <section> <h5 id="ruby_2" data-text="Ruby">Ruby</h5> <pre class="prettyprint" translate="no" dir="ltr"> firestore.batch do |b| # Set the data for NYC b.set "#{collection_path}/NYC", name: "New York City" # Update the population for SF b.update "#{collection_path}/SF", population: 1_000_000 # Delete LA b.delete "#{collection_path}/LA" end<div class="devsite-github-link nocode no-select"><a target="_top" href="https://web.archive.org/web/20210127075900/https://github.com/googleapis/google-cloud-ruby/blob/146b9fbd185ff9018f6d3bca573cf8e875db3ab0/google-cloud-firestore/samples/transactions_and_batched_writes.rb#L68-L77" class="gc-analytics-event" data-category="github_link" data-label="googleapis/google-cloud-ruby/google-cloud-firestore/samples/transactions_and_batched_writes.rb#fs_batch_write" data-code-snippet="true" data-github-path="googleapis/google-cloud-ruby/google-cloud-firestore/samples/transactions_and_batched_writes.rb" data-region-tag="fs_batch_write">transactions_and_batched_writes.rb</a></div> </pre> </section> </div> <p>A batched write can contain up to 500 operations. Each operation in the batch counts separately towards your Cloud Firestore usage. Within a write operation, field transforms like <code translate="no" dir="ltr">serverTimestamp</code>, <code translate="no" dir="ltr">arrayUnion</code>, and <code translate="no" dir="ltr">increment</code> each count as an additional operation.</p> <p>Like transactions, batched writes are atomic. Unlike transactions, batched writes do not need to ensure that read documents remain un-modified which leads to fewer failure cases. They are not subject to retries or to failures from too many retries. Batched writes execute even when the user's device is offline.</p> <aside class="note"><strong>Note:</strong><span> For bulk data entry, use a <a href="/web/20210127075900/https://firebase.google.com/docs/firestore/client/libraries#server_client_libraries">server client library</a> with parallelized individual writes. Batched writes perform better than serialized writes but not better than parallel writes. You should use a server client library for bulk data operations and not a mobile/web SDK.</span></aside> <h2 id="data_validation_for_atomic_operations" data-text="Data validation for atomic operations">Data validation for atomic operations</h2> <p>For mobile/web client libraries, you can validate data using <a href="https://web.archive.org/web/20210127075900/https://firebase.google.com/docs/firestore/security/get-started">Cloud Firestore Security Rules</a>. You can ensure that related documents are always updated atomically and always as part of a transaction or batched write. Use the <a href="https://web.archive.org/web/20210127075900/https://firebase.google.com/docs/reference/rules/rules.firestore#.getAfter"><code translate="no" dir="ltr">getAfter()</code></a> security rule function to access and validate the state of a document after a set of operations completes but <em>before</em> Cloud Firestore commits the operations.</p> <p>For example, imagine that the database for the <code translate="no" dir="ltr">cities</code> example also contains a <code translate="no" dir="ltr">countries</code> collection. Each <code translate="no" dir="ltr">country</code> document uses a <code translate="no" dir="ltr">last_updated</code> field to keep track of the last time any city related to that country was updated. The following security rules require that an update to a <code translate="no" dir="ltr">city</code> document must also atomically update the related country's <code translate="no" dir="ltr">last_updated</code> field:</p> <pre class="prettyprint" translate="no" dir="ltr"> service cloud.firestore { match /databases/{database}/documents { // If you update a city doc, you must also // update the related country's last_updated field. match /cities/{city} { allow write: if request.auth != null && getAfter( /databases/$(database)/documents/countries/$(request.resource.data.country) ).data.last_updated == request.time; } match /countries/{country} { allow write: if request.auth != null; } } } </pre> <h3 id="security_rules_limits" data-text="Security rules limits">Security rules limits</h3> <p>In security rules for transactions or batched writes, there is a <a href="https://web.archive.org/web/20210127075900/https://firebase.google.com/docs/firestore/quotas#security_rules">limit</a> of 20 document access calls for the entire atomic operation in addition to the normal 10 call limit for each single document operation in the batch.</p> <p>For example, consider the following rules for a chat application:</p> <pre class="prettyprint" translate="no" dir="ltr"> service cloud.firestore { match /databases/{db}/documents { function prefix() { return /databases/{db}/documents; } match /chatroom/{roomId} { allow read, write: if request.auth != null && roomId in get(/$(prefix())/users/$(request.auth.uid)).data.chats || exists(/$(prefix())/admins/$(request.auth.uid)); } match /users/{userId} { allow read, write: if request.auth != null && request.auth.uid == userId || exists(/$(prefix())/admins/$(request.auth.uid)); } match /admins/{userId} { allow read, write: if request.auth != null && exists(/$(prefix())/admins/$(request.auth.uid)); } } } </pre> <p>The snippets below illustrate the number of document access calls used for a few data access patterns:</p> <pre class="prettyprint" translate="no" dir="ltr"> // 0 document access calls used, because the rules evaluation short-circuits // before the exists() call is invoked. db.collection('user').doc('myuid').get(...); // 1 document access call used. The maximum total allowed for this call // is 10, because it is a single document request. db.collection('chatroom').doc('mygroup').get(...); // Initializing a write batch... var batch = db.batch(); // 2 document access calls used, 10 allowed. var group1Ref = db.collection("chatroom").doc("group1"); batch.set(group1Ref, {msg: "Hello, from Admin!"}); // 1 document access call used, 10 allowed. var newUserRef = db.collection("users").doc("newuser"); batch.update(newUserRef, {"lastSignedIn": new Date()}); // 1 document access call used, 10 allowed. var removedAdminRef = db.collection("admin").doc("otheruser"); batch.delete(removedAdminRef); // The batch used a total of 2 + 1 + 1 = 4 document access calls, out of a total // 20 allowed. batch.commit(); </pre> </div> <devsite-page-rating position="footer" selected-rating="0" hover-rating-star="0"> </devsite-page-rating> <devsite-feedback position="footer" project-name="Firebase" product-id="719752" bucket="" context="" version="t-devsite-webserver-20210114-r02-rc00.432497685912973661" 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://firebase.google.com/_static/firebase/images/logo.png" project-support-url="https://firebase.google.com/support/" feedback-type="star-rating"> <button> Send feedback </button> </devsite-feedback> </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/20210127075900/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/20210127075900/https://www.apache.org/licenses/LICENSE-2.0">Apache 2.0 License</a>. 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