Guide to Foreground Services

Foreground services are an essential component for executing long-running tasks on Android. However, as each new Android version introduces changes and limitations, implementing them correctly has become increasingly challenging. In this session, we will cover what a foreground service is, the changes introduced in recent Android versions, and how to update your apps to target the latest SDK versions. You will learn about different types of foreground services and common errors to avoid. We will also explore alternative approaches for handling background work. Additionally, we will take a practical look at how to correctly implement foreground services through a sample project. Walk away feeling confident you can leverage foreground services for long-running work in your apps.

Transcript

1. Guide to Foreground Services droidcon London 2025 Domen Lanišnik Senior Android Engineer @ DuckDuckGo
2. Why Foreground Services? 🤔
4. Haven’t foreground services existed since the beginning? 😅
5. Because of the frequent API and behavioral changes 😅 API 28 API 29 API 30 API 31 API 33 API 34 API 35 API 36
6. Android 9 API 28 API 29 API 30 API 31 API 33 API 34 API 35 API 36 • Introduced a new mandatory permission
 FOREGROUND_SERVICE 🆕
7. Android 10 API 28 API 29 API 30 API 31 API 33 API 34 API 35 API 36 • Introduced concept of foreground service type 🆕 • Mandatory for location 🧭
8. Android 11 API 28 API 29 API 30 API 31 API 33 API 34 API 35 API 36 • New 📸 and 🎤 foreground service types 🆕 • Restrictions to access 📸 and 🎤 when 
 FGS started from background 🤚
9. Android 12 API 28 API 29 API 30 API 31 API 33 API 34 API 35 API 36 • Restrictions on starting a FGS while in the background 🤚
10. Android 13 API 28 API 29 API 30 API 31 API 33 API 34 API 35 API 36 • Introduced noti fi cation permissions 🆕 • FGS noti fi cations can be dismissed 🔕
11. Android 14 API 28 API 29 API 30 API 31 API 33 API 34 API 35 API 36 • Foreground service type become mandatory ⚠ • Introduced new types 🆕
12. Android 15 API 28 API 29 API 30 API 31 API 33 API 34 API 35 API 36 • New type for media processing 🆕 • Boot completed receivers can’t launch some types of FGS 📵 • Introduced service timeouts ⏲
13. Android 16 API 28 API 29 API 30 API 31 API 33 API 34 API 35 API 36 • Background jobs started from a FGS must adhere to their respective runtime quotas ⚠ • New granular health permissions that
 a ff ect the health type 🏥
14. What is next in Android 17 and beyond? 😅
15. Likely more limitations is a solid guess 😢
16. What is a Service? 🤔
17. Broadcast receivers Content providers App Components Activities Services
18. Service • Perform long-running operations in the background ⏳ • No user interface 🙈 • Components can bind to it and interact with it ↔
20. • User-initiated, time-sensitive tasks ⏱ • User-visible 📢 • Can run even after app is stopped 🏃 • Prioritized by the system ⬆ • Restricted background usage ⚠ Foreground Service
21. Background Foreground • User-initiated tasks ⏱ • App-internal tasks 🧹 • User-visible 📢 • Runs silently 🙈 • Even when app stopped 🏃 • While the app is running 🫠 • Prioritized by the system ⬆ • No prioritization ⬇ Restricted background usage ⚠
22. What is a Foreground Service Type? 🤔
23. • Simple string type ✍ • Declared in manifest and service 📝 • Describes the work 📝 Foreground Service Type
24. <service android:name=".service.ExampleForegroundService" android:exported="false" android:foregroundServiceType="camera" />
25. ServiceCompat.startForeground( this, // service 1, // notification ID notification, // notification to display if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) { ServiceInfo.FOREGROUND_SERVICE_TYPE_LOCATION } else { 0 } )
26. Foreground Service Types camera 📷 connectedDevice 🎧 dataSync 🔄 health 🩺 location 🧭 mediaPlayback ▶ mediaProjection 📺 microphone 🎤 phoneCall 📲 remoteMessaging 💬 shortService ⚠ specialUse ⚠ systemExempted ⚠ mediaProcessing 📀 https://developer.android.com/develop/background-work/services/fg-service-types
27. • Ensures correct usage ✅ • Brings consistency across devices 📱 • Defines runtime pre-requisites 📋 • Mandatory since Android 14❗ • Multiple types at once 🅰 🅱 Foreground Service Type
28. What are runtime pre-requisites? 🤔
29. You need to have all necessary permissions BEFORE you start the service 📋
30. • When interacting with an external device through BT, NFC, USB or WiFi 📲 • Several Runtime prerequisites (at least one of the following) ➡ connectedDevice Foreground Service Type
31. • Declare one of the permissions in manifest: • CHANGE_NETWORK_STATE • CHANGE_WIFI_STATE • CHANGE_WIFI_MULTICAST_STATE, • NFC, • TRANSMIT_IR connectedDevice Foreground Service Type
32. • OR one of the runtime permissions: • BLUETOOTH_CONNECT • BLUETOOTH_SCAN • BLUETOOTH_ADVERTISE • BLUETOOTH_SCAN • UWB_RANGING connectedDevice Foreground Service Type
33. • OR call UsbManager.requestPermission() • Only after one of the following is true, can you start the service ✅ connectedDevice Foreground Service Type
34. When CAN you start a FGS? ✅
35. When can you start a FGS? • When app is in foreground ✅ • App transitions from a user-visible state 🏃 • App receives a high-priority message using FCM* 🚨 • App receives BOOT_COMPLETED action* 🥾 • … https://developer.android.com/develop/background-work/services/foreground-services#background-start-restriction-exemptions
36. When can you NOT? ❌
37. https://developer.android.com/develop/background-work/services/foreground-services#wiu-restrictions When can you not? ❌ • When app is in background 🙈 • Service needs while-in-use permissions* 📸 🎤 🧭
38. What happens if you start a FGS when you shouldn’t? 😅
39. 💥 ForegroundServiceStartNotAllowedException
40. Notifications 📢
41. Notifications • Required when starting a FGS ❗ • Visible for the duration of the service 👀 • Requires channels, runtime permissions, … ⚠
42. Any special behavior around notifications? 😅
43. Notifications • Android 12 and newer: • System waits 10 seconds before showing it
44. Notifications • Android 13 and newer: • Notification is dismissible • App is shown in task manager
45. Play Console Declaration 📝
47. Play Console Declaration https://developer.android.com/develop/background-work/services/fg-service-types#google-play-enforcement • Describe app functionality 📝 • Describe user impact if task deferred or interrupted ⏹ • Include a link to a demo video 📹 • Select from a pre-defined list of use cases 📋
48. That seems difficult. Should I use something else? 🤔
49. When to choose a Foreground Service? 🤔
50. 1⃣ Should the task continue while the app in in background?
51. No?
52. Coroutines RxJava Asynchronous work
53. Yes, continue in the background?
54. 2⃣ Acceptable if the task is deferred or interrupted?
55. Yes?
56. WorkManager JobScheduler Task scheduling APIs
57. No, should not be interrupted?
58. 3⃣ Is it a short critical task?
59. Yes?
60. < 3 minutes Special FGS
61. Not a short task?
62. 4⃣ Alternative API available?
63. Yes?
64. Alternative APIs Geofence API CompanionDevice Manager … Bluetooth Scan API
65. • Continuous data transfer to external device -> CompanionDeviceManager 📲 • Scanning for BT devices -> Bluetooth scan API 🔀 connectedDevice Foreground Service Type
66. No alternative API?
67. Foreground Service is the right choice 👍 👍
68. Are there any time limitations? 🤔
69. • From Android 15 for dataSync and mediaProcessing types ⏳ • 6 hours per 24h per type ⏰ • System calls onTimeout(), giving you a few seconds to stop 🛑 Service Timeouts
70. What if you don’t stop the service? 😏
71. ANR ⚠ A foreground service of TYPE did not stop within its timeout: COMPONENT_NAME
72. What if you simply restart the service? 😏
73. 💥 ForegroundServiceStartNotAllowedException “Time limit already exhausted for foreground service type dataSync"
74. What if I need to respond to an event while app is in the background? 🤔
75. • Broadcast message 🔊 • FCM Message 💬 • Alarm set by the app ⏰ Responding to an event
76. 1⃣ Can the work finish in few seconds?
77. Yes?
78. Coroutines RxJava Asynchronous work
79. No, it will take longer?
80. 2⃣ User-initiated & needs to run immediately?
81. No, and it can run a bit later?
82. WorkManager JobScheduler Task scheduling APIs
83. Yes, and it needs to run immediately?
84. 3⃣ Is app in foreground, or can start from background?
85. No?
86. WorkManager JobScheduler Task scheduling APIs
87. Yes, it’s in foreground or allowed to start from background?
88. Foreground Service is the right choice 👍 👍
89. How to create a Foreground Service? 🏗
90. How to create a Foreground Service? 1⃣ Create a Service and elevate it to foreground 🛠 2⃣ Use WorkManager to define a long- running Worker 🔧
91. 1⃣.0⃣ The “Typical” Way 🛠
92. 1⃣.1⃣ Create a Service 🏗
93. class ExampleForegroundService : Service() { override fun onStartCommand(…): Int { // TODO Start as foreground service return super.onStartCommand(intent, flags, startId) } }
94. 1⃣.2⃣ Declare service 📝
95. <service android:name=".service.ExampleForegroundService" android:exported="false" />
96. 1⃣.3⃣ Declare FGS type 📝
97. <service android:name=".service.ExampleForegroundService" android:exported="false" android:foregroundServiceType="location" />
98. What if you forget to declare the type? 😅
99. 💥 MissingForegroundServiceTypeException
100. 1⃣.4⃣ Declare runtime permissions 📝
101. <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
102. 1⃣.5⃣ Declare FGS runtime permissions 📝
103. <!- - Request the general foreground service permission -- > <uses-permission android:name="android.permission.FOREGROUND_SERVICE" / > <!- - Request the specific foreground service permission for each declared type --> <uses-permission android:name="android.permission.FOREGROUND_SERVICE_LOCATION" />
104. What if you forget to declare the general one? 😅
105. 💥 java.lang.SecurityException: Permission Denial: startForeground from pid=8589, uid=10623 requires android.permission.FOREGROUND_SERVICE
106. What if you forget to declare the type one? 😅
107. 💥 java.lang.SecurityException: Starting FGS with type location targetSDK=34 requires permissions: all of the permissions allOf=true [android.permission.FOREGROUND_SERVICE_LOCATION]
108. 1⃣.6⃣ Elevate service to foreground 📣
109. override fun onStartCommand(…): Int { ServiceCompat.startForeground( this, // service 1, // notification ID notification, // notification to display if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) { ServiceInfo.FOREGROUND_SERVICE_TYPE_LOCATION } else { 0 } ) return super.onStartCommand(intent, flags, startId) }
110. What if you pass 0 for the type? 😅
111. 💥 android.app.InvalidForegroundServiceTypeException: Starting FGS with type none targetSDK=34 has been prohibited
112. What if you pass an undeclared type? 😅
113. 💥 java.lang.IllegalArgumentException: foregroundServiceType 0x00000002 is not a subset of foregroundServiceType attribute 0x00000000 in service element of manifest file
114. What if you don’t call startForeground() quick enough? 😅
115. 💥 android.app.ForegroundServiceDidNotStartInTimeException: Context.startForegroundService() did not then call Service.startForeground()
116. 1⃣.7⃣ Start the service 🎬
117. val serviceIntent = Intent( this, ExampleForegroundService :: class.java ) context.startForegroundService(serviceIntent)
118. Crash?!
119. 💥 java.lang.SecurityException: Starting FGS with type location targetSDK=34 requires permissions: - all of the permissions allOf=true - [android.permission.FOREGROUND_SERVICE_LOCATION] - any of the permissions allOf=false - [android.permission.ACCESS_COARSE_LOCATION, android.permission.ACCESS_FINE_LOCATION]
120. 1⃣.7⃣ Fulfill runtime pre-requisites ✅
121. private val locationPermissionRequest = registerForActivityResult( ActivityResultContracts.RequestPermission() ) { granted -> if (granted) { / / Precise location access granted, service can run startForegroundService() } else { } } locationPermissionRequest.launch(ACCESS_FINE_LOCATION)
122. override fun onStartCommand(…): Int { val fineLocationPermission = PermissionChecker.checkSelfPermission(this, ACCESS_FINE_LOCATION) if (fineLocationPermission ! = PermissionChecker.PERMISSION_GRANTED) { / / stop the service if we don't have the necessary permissions stopSelf() } else { startAsForegroundService() startLocationUpdates() } return super.onStartCommand(intent, flags, startId) }
123. 1⃣.8⃣ Stop the service 🛑
124. Stopping a service • stopForeground() for removing the service from foreground only 🔕 • stopSelf() for stopping the entire service 🛑
125. What about threading? 🤔
126. Services run on the main thread by default ⚠
127. 2⃣.0⃣ The WorkManager Way
128. Create FGS using WorkManager • Built-in support for long running workers ⏳ • Can run longer than 10 minutes 🕙 • Manages and runs a FGS on your behalf 😌 • Examples: tasks important to user 🧑💻, uploads/ downloads 🔁, local ML models 🤖, …
129. 2⃣.1⃣ Declare service 📝
130. <service android:name="androidx.work.impl.foreground.SystemForegroundService" android:foregroundServiceType="location" tools:node="merge" / >
131. 2⃣.2⃣ Declare runtime permissions 📝
132. <uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" /> <uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
133. 2⃣.3⃣ Declare FGS runtime permissions 📝
134. <!- - Request the general foreground service permission -- > <uses-permission android:name="android.permission.FOREGROUND_SERVICE" / > <!- - Request the specific foreground service permission for each declared type --> <uses-permission android:name="android.permission.FOREGROUND_SERVICE_LOCATION" />
135. 2⃣.4⃣ Create a Worker 🏋
136. class ForegroundWorker( private val appContext: Context, params: WorkerParameters ) : CoroutineWorker(appContext, params) { override suspend fun doWork(): Result { setForeground(createForegroundInfo()) processLocationUpdates() return Result.success() } private fun createForegroundInfo(): ForegroundInfo { // TODO } }
137. 2⃣.5⃣ Build notification 📣
138. private fun createForegroundInfo(): ForegroundInfo { NotificationsHelper.createNotificationChannel(appContext) val notification = NotificationsHelper.buildNotification(appContext) return ForegroundInfo( 1, notification, if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.R) { ServiceInfo.FOREGROUND_SERVICE_TYPE_LOCATION } else { 0 } ) }
139. 2⃣.6⃣ Enqueue work 🔗
140. val workRequest = OneTimeWorkRequestBuilder<ForegroundWorker>() .setExpedited(OutOfQuotaPolicy.DROP_WORK_REQUEST) .setConstraints( Constraints.Builder() .setRequiredNetworkType(NetworkType.CONNECTED) .build() ) .build() WorkManager.getInstance(this) .enqueue(workRequest)
141. Anything to be aware of with the WorkManager way? 🤔
142. What to watch out for with WM? • FGS types and pre-requisites still apply ⚠ • Only use when the work is important to the user 🧑💻 • Also requires Play Store declaration 📝 • On Android 16 can exhaust the job quota ‼
143. Sample app • Foreground service for location updates • Handling runtime permissions • Binding to the service to update UI • Stopping the service from the UI • Using WorkManager approach https://github.com/landomen/ForegroundServiceSamples
144. Why so much friction? 🤔
145. Why so much friction? • More intentional usage 🧐 • Use purpose-built APIs and
 WorkManager instead 🎯 • Protect users 🛡
146. What have we learned? 👩🏫
147. Summary • Foreground Services can be tricky 😅 • Consider other approaches first 📋 • Use the appropriate type to ensure compliancy ✅ • Two ways to create a FGS 🏗
148. Thank you! droidcon London 2025 Guide to Foreground Services