# Mobile App Lifecycle Events ## How it works[](#how-it-works) Our [Mobile App Lifecycle Event specification](/integrations/api/cdp/mobile-app/) helps you send events in a uniform format that automatically maps data to the integrations we support. Following this spec makes it easier to use data from your mobile apps without having to re-map your incoming data each time you set up a new integration. These events typically contain information about your app version and build. If you use our SDKs, we capture some of the following events automatically. Some, like `Application Crashed`, are events you’ll send manually. ## Our mobile SDKs send lifecycle events automatically[](#mobile-sdks) If you use one of our [mobile SDKs](/integrations/sdk/), we automatically capture the following events by default. * Application Installed * Application Opened * Application Backgrounded * Application Foregrounded * Application Updated These events can help you understand your customer’s lifecycle—like the time they spend in the app (time from opened to backgrounded), how often they update the app, and so on. You’ll notice that our mobile SDKs don’t capture events like `Application Crashed` automatically. That’s because the app must be open for us to send events from your app to Customer.io. These are the minimum required versions of our mobile SDKs to capture application lifecycle events. If you’re running an earlier version, update the SDK to take advantage of these events and other features! SDK Minimum version for lifecycle events Android 3.0 iOS 4.0 React Native 4.0 Flutter 2.0 Expo 2.0 ## Application Installed[](#application-installed) Our CDP-enabled SDKs send this event the *first* time a user opens your application. If the user never opens your app, we won’t be able to collect this event. This event doesn’t wait for the SDK to capture attribution or campaign information, and is collected automatically. Platforms like Facebook and Google require discrete install events to correctly attribute installs to ads served through their platforms. ```json { "userId": "019mr8mf4r", "type": "track", "event": "Application Installed", "properties": { "version": "1.2.3", "build": "1234" } } ``` * event string A person installed your app. Accepted values:`Application Installed` * properties object The properties typically sent with the event. * build string The specific build of the app installed. * version string The version of the app installed. * event string A person installed your app. Accepted values:`Application Installed` * properties object The properties typically sent with the event. * build string The specific build of the app installed. * version string The version of the app installed. ## Application Opened[](#application-opened) Send this event when a user launches your mobile application—after the first open. The first open results in an `Application Installed` event, so we only send this event on subsequent opens. Like the `Application Installed` event, this event also does not wait for the SDK to capture attribution information but it *can* include information about referring applications or deep link URLs if available when the app opens. ```json { "userId": "019mr8mf4r", "type": "track", "event": "Application Opened", "properties": { "from_background": false, "referring_application": "GMail", "url": "url://location" } } ``` * event string A person opened your app. Our SDKs automatically send this event when a person opens your app fresh or when they return to the app after sending it to the the background. Accepted values:`Application Opened` * properties object The properties typically sent with the event. * build string The specific build of the app opened. * from\_background boolean If true, the user opened the app from the background. * url string The value of `UIApplicationLaunchOptionsURLKey` from launchOptions. Collected on iOS only. * version string The version of the app opened. * event string A person opened your app. Our SDKs automatically send this event when a person opens your app fresh or when they return to the app after sending it to the the background. Accepted values:`Application Opened` * properties object The properties typically sent with the event. * build string The specific build of the app opened. * from\_background boolean If true, the user opened the app from the background. * url string The value of `UIApplicationLaunchOptionsURLKey` from launchOptions. Collected on iOS only. * version string The version of the app opened. ## Application Backgrounded[](#application-backgrounded) Send this event when a user backgrounds the application upon [`applicationDidEnterBackground`](https://developer.apple.com/reference/uikit/uiapplicationdelegate/1622997-applicationdidenterbackground). ```json { "userId": "019mr8mf4r", "type": "track", "event": "Application Backgrounded", "properties": {} } ``` * event string A person sent your app to the background. Our SDKs automatically send this event when a person backgrounds your app. Accepted values:`Application Backgrounded` * properties object There are no default properties for the `Application Backgrounded` event. You can add custom properties to the event payload. * event string A person sent your app to the background. Our SDKs automatically send this event when a person backgrounds your app. Accepted values:`Application Backgrounded` * properties object There are no default properties for the `Application Backgrounded` event. You can add custom properties to the event payload. ## Application Foregrounded[](#application-foregrounded) Send this event when your audience returns to your app after previously backgrounding it. This event is distinct from `Application Opened` in that the app is considered opened already, even if it’s in the background. ```json { "userId": "019mr8mf4r", "type": "track", "event": "Application Foregrounded", "properties": {} } ``` * event string A person brought your app to the foreground after having backgrounded it, indicating that they’re using it again. Our SDKs automatically send this event when a person brings your app back to the foreground. Accepted values:`Application Foregrounded` * properties object There are no default properties for the `Application Foregrounded` event. You can add custom properties to the event payload. * event string A person brought your app to the foreground after having backgrounded it, indicating that they’re using it again. Our SDKs automatically send this event when a person brings your app back to the foreground. Accepted values:`Application Foregrounded` * properties object There are no default properties for the `Application Foregrounded` event. You can add custom properties to the event payload. ## Application Updated[](#application-updated) This event fires when the user opens your app *after* updating your app. Our CDP-enabled SDKs automatically collect this event rather than the “Application Opened” event after someone updates your app. ```json { "userId": "019mr8mf4r", "type": "track", "event": "Application Updated", "properties": { "previous_version": "1.1.2", "previous_build": "1234", "version": "1.2.0", "build": "1456" } } ``` * event string A person updated your app. Accepted values:`Application Updated` * properties object The properties typically sent with the event. * build string The specific build of the app the person upgraded to. * previous\_build string The previous build of the app installed—the build a person is upgrading *from*. * previous\_version string The previous version of the app installed—the version a person is upgrading *from*. * version string The version of the app a person upgraded to. * event string A person updated your app. Accepted values:`Application Updated` * properties object The properties typically sent with the event. * build string The specific build of the app the person upgraded to. * previous\_build string The previous build of the app installed—the build a person is upgrading *from*. * previous\_version string The previous version of the app installed—the version a person is upgrading *from*. * version string The version of the app a person upgraded to. ## Application Uninstalled[](#application-uninstalled) You can send this event when a user uninstalls your app. Like similar events that happen outside of your app itself, our CDP-enabled SDKs cannot capture this event automatically. However, some direct-mode destinations detect this for you using silent push notifications through their own SDKs. You might also be able to send these events to Customer.io using callbacks. ```json { "userId": "019mr8mf4r", "type": "track", "event": "Application Uninstalled", "properties": {} } ``` * event string A person uninstalled your app. Accepted values:`Application Uninstalled` * properties object There are no default properties for the `Application uninstalled` event. You can add custom properties to the event payload. * event string A person uninstalled your app. Accepted values:`Application Uninstalled` * properties object The properties typically sent with the event. ## Application Crashed[](#application-crashed) You can send this event when you receive a crash notification from your app, but it is not meant to supplant traditional crash reporting tools. By tracking crashes this way, you can analyze which types of users are impacted by crashes and how those crashes affect their engagement. You may also want to send messages to users who experience crashes through other messaging channels. Like similar events that happen outside of your app itself, our CDP-enabled SDKs cannot capture this event automatically. But you might be able to capture this kind of event with a callback or a webhook. ```json { "userId": "019mr8mf4r", "type": "track", "event": "Application Crashed", "properties": {} } ``` * event string A person experienced a crash in your app. Our SDKs automatically send this event when a person experiences a crash in your app. Accepted values:`Application Crashed` * properties object There are no default properties for the `Application Crashed` event. You can add custom properties to the event payload. * event string A person experienced a crash in your app. Our SDKs automatically send this event when a person experiences a crash in your app. Accepted values:`Application Crashed` * properties object There are no default properties for the `Application Crashed` event. You can add custom properties to the event payload.