chore: remote config api

CHANGELOG.md

@@ -1,5 +1,7 @@
 ## Next
 
+- feat: use remote config API ([#233](https://github.com/PostHog/posthog-android/pull/233))
+
 ## 3.12.0 - 2025-03-10
 
 - feat: support reuse of `anonymousId` between user changes ([#229](https://github.com/PostHog/posthog-android/pull/229))

posthog-android/lint-baseline.xml

@@ -45,4 +45,26 @@
             column="17"/>
     </issue>
 
+    <issue
+        id="GradleDependency"
+        message="A newer version of org.codehaus.mojo:animal-sniffer-annotations than 1.23 is available: 1.24"
+        errorLine1="    compileOnly(&quot;org.codehaus.mojo:animal-sniffer-annotations:${PosthogBuildConfig.Plugins.ANIMAL_SNIFFER_SDK_ANNOTATION}&quot;)"
+        errorLine2="                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~">
+        <location
+            file="build.gradle.kts"
+            line="94"
+            column="17"/>
+    </issue>
+
+    <issue
+        id="GradleDependency"
+        message="A newer version of com.squareup.okhttp3:mockwebserver than 4.11.0 is available: 4.12.0"
+        errorLine1="    testImplementation(&quot;com.squareup.okhttp3:mockwebserver:${PosthogBuildConfig.Dependencies.OKHTTP}&quot;)"
+        errorLine2="                       ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~">
+        <location
+            file="build.gradle.kts"
+            line="109"
+            column="24"/>
+    </issue>
+
 </issues>

posthog/api/posthog.api

@@ -71,9 +71,13 @@ public final class com/posthog/PostHog$Companion : com/posthog/PostHogInterface
 
 public class com/posthog/PostHogConfig {
 	public static final field Companion Lcom/posthog/PostHogConfig$Companion;
+	public static final field DEFAULT_EU_ASSETS_HOST Ljava/lang/String;
+	public static final field DEFAULT_EU_HOST Ljava/lang/String;
 	public static final field DEFAULT_HOST Ljava/lang/String;
-	public fun <init> (Ljava/lang/String;Ljava/lang/String;ZZZZIIIILcom/posthog/PostHogEncryption;Lcom/posthog/PostHogOnFeatureFlags;ZLcom/posthog/PostHogPropertiesSanitizer;Lkotlin/jvm/functions/Function1;ZLcom/posthog/PersonProfiles;)V
-	public synthetic fun <init> (Ljava/lang/String;Ljava/lang/String;ZZZZIIIILcom/posthog/PostHogEncryption;Lcom/posthog/PostHogOnFeatureFlags;ZLcom/posthog/PostHogPropertiesSanitizer;Lkotlin/jvm/functions/Function1;ZLcom/posthog/PersonProfiles;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
+	public static final field DEFAULT_US_ASSETS_HOST Ljava/lang/String;
+	public static final field DEFAULT_US_HOST Ljava/lang/String;
+	public fun <init> (Ljava/lang/String;Ljava/lang/String;ZZZZZIIIILcom/posthog/PostHogEncryption;Lcom/posthog/PostHogOnFeatureFlags;ZLcom/posthog/PostHogPropertiesSanitizer;Lkotlin/jvm/functions/Function1;ZLcom/posthog/PersonProfiles;)V
+	public synthetic fun <init> (Ljava/lang/String;Ljava/lang/String;ZZZZZIIIILcom/posthog/PostHogEncryption;Lcom/posthog/PostHogOnFeatureFlags;ZLcom/posthog/PostHogPropertiesSanitizer;Lkotlin/jvm/functions/Function1;ZLcom/posthog/PersonProfiles;ILkotlin/jvm/internal/DefaultConstructorMarker;)V
 	public final fun addIntegration (Lcom/posthog/PostHogIntegration;)V
 	public final fun getApiKey ()Ljava/lang/String;
 	public final fun getCachePreferences ()Lcom/posthog/internal/PostHogPreferences;
@@ -96,6 +100,7 @@ public class com/posthog/PostHogConfig {
 	public final fun getPersonProfiles ()Lcom/posthog/PersonProfiles;
 	public final fun getPreloadFeatureFlags ()Z
 	public final fun getPropertiesSanitizer ()Lcom/posthog/PostHogPropertiesSanitizer;
+	public final fun getRemoteConfig ()Z
 	public final fun getReplayStoragePrefix ()Ljava/lang/String;
 	public final fun getReuseAnonymousId ()Z
 	public final fun getSdkName ()Ljava/lang/String;
@@ -124,6 +129,7 @@ public class com/posthog/PostHogConfig {
 	public final fun setPersonProfiles (Lcom/posthog/PersonProfiles;)V
 	public final fun setPreloadFeatureFlags (Z)V
 	public final fun setPropertiesSanitizer (Lcom/posthog/PostHogPropertiesSanitizer;)V
+	public final fun setRemoteConfig (Z)V
 	public final fun setReplayStoragePrefix (Ljava/lang/String;)V
 	public final fun setReuseAnonymousId (Z)V
 	public final fun setSdkName (Ljava/lang/String;)V

posthog/src/main/java/com/posthog/PostHog.kt

@@ -2,7 +2,6 @@ package com.posthog
 
 import com.posthog.internal.PostHogApi
 import com.posthog.internal.PostHogApiEndpoint
-import com.posthog.internal.PostHogFeatureFlags
 import com.posthog.internal.PostHogMemoryPreferences
 import com.posthog.internal.PostHogNoOpLogger
 import com.posthog.internal.PostHogPreferences
@@ -17,6 +16,7 @@ import com.posthog.internal.PostHogPreferences.Companion.PERSON_PROCESSING
 import com.posthog.internal.PostHogPreferences.Companion.VERSION
 import com.posthog.internal.PostHogPrintLogger
 import com.posthog.internal.PostHogQueue
+import com.posthog.internal.PostHogRemoteConfig
 import com.posthog.internal.PostHogSendCachedEventsIntegration
 import com.posthog.internal.PostHogSerializer
 import com.posthog.internal.PostHogSessionManager
@@ -35,9 +35,9 @@ public class PostHog private constructor(
         Executors.newSingleThreadScheduledExecutor(
             PostHogThreadFactory("PostHogReplayQueueThread"),
         ),
-    private val featureFlagsExecutor: ExecutorService =
+    private val remoteConfigExecutor: ExecutorService =
         Executors.newSingleThreadScheduledExecutor(
-            PostHogThreadFactory("PostHogFeatureFlagsThread"),
+            PostHogThreadFactory("PostHogRemoteConfigThread"),
         ),
     private val cachedEventsExecutor: ExecutorService =
         Executors.newSingleThreadScheduledExecutor(
@@ -59,7 +59,7 @@ public class PostHog private constructor(
 
     private var config: PostHogConfig? = null
 
-    private var featureFlags: PostHogFeatureFlags? = null
+    private var remoteConfig: PostHogRemoteConfig? = null
     private var queue: PostHogQueue? = null
     private var replayQueue: PostHogQueue? = null
     private var memoryPreferences = PostHogMemoryPreferences()
@@ -86,7 +86,7 @@ public class PostHog private constructor(
                 val api = PostHogApi(config)
                 val queue = PostHogQueue(config, api, PostHogApiEndpoint.BATCH, config.storagePrefix, queueExecutor)
                 val replayQueue = PostHogQueue(config, api, PostHogApiEndpoint.SNAPSHOT, config.replayStoragePrefix, replayExecutor)
-                val featureFlags = PostHogFeatureFlags(config, api, featureFlagsExecutor)
+                val featureFlags = PostHogRemoteConfig(config, api, remoteConfigExecutor)
 
                 // no need to lock optOut here since the setup is locked already
                 val optOut =
@@ -110,7 +110,7 @@ public class PostHog private constructor(
                 this.config = config
                 this.queue = queue
                 this.replayQueue = replayQueue
-                this.featureFlags = featureFlags
+                this.remoteConfig = featureFlags
 
                 config.addIntegration(sendCachedEventsIntegration)
 
@@ -131,7 +131,9 @@ public class PostHog private constructor(
                 }
 
                 // only because of testing in isolation, this flag is always enabled
-                if (reloadFeatureFlags && config.preloadFeatureFlags) {
+                if (reloadFeatureFlags && config.remoteConfig) {
+                    loadRemoteConfigRequest(config.onFeatureFlags)
+                } else if (reloadFeatureFlags && config.preloadFeatureFlags) {
                     loadFeatureFlagsRequest(config.onFeatureFlags)
                 }
             } catch (e: Throwable) {
@@ -299,7 +301,7 @@ public class PostHog private constructor(
             }
 
             if (config?.sendFeatureFlagEvent == true) {
-                featureFlags?.getFeatureFlags()?.let {
+                remoteConfig?.getFeatureFlags()?.let {
                     if (it.isNotEmpty()) {
                         val keys = mutableListOf<String>()
                         for (entry in it.entries) {
@@ -702,7 +704,29 @@ public class PostHog private constructor(
             return
         }
 
-        featureFlags?.loadFeatureFlags(distinctId, anonymousId = anonymousId, groups, onFeatureFlags)
+        val calledFromRemoteConfig = config?.remoteConfig ?: false
+        // only process remote config if the remote config API is disabled
+        remoteConfig?.loadFeatureFlags(
+            distinctId,
+            anonymousId = anonymousId,
+            groups,
+            calledFromRemoteConfig = calledFromRemoteConfig,
+            onFeatureFlags,
+        )
+    }
+
+    private fun loadRemoteConfigRequest(onFeatureFlags: PostHogOnFeatureFlags?) {
+        @Suppress("UNCHECKED_CAST")
+        val groups = getPreferences().getValue(GROUPS) as? Map<String, String>
+
+        val distinctId = this.distinctId
+        var anonymousId: String? = null
+
+        if (config?.reuseAnonymousId != true) {
+            anonymousId = this.anonymousId
+        }
+
+        remoteConfig?.loadRemoteConfig(distinctId, anonymousId = anonymousId, groups, onFeatureFlags)
     }
 
     public override fun isFeatureEnabled(
@@ -712,7 +736,7 @@ public class PostHog private constructor(
         if (!isEnabled()) {
             return defaultValue
         }
-        val value = featureFlags?.isFeatureEnabled(key, defaultValue) ?: defaultValue
+        val value = remoteConfig?.isFeatureEnabled(key, defaultValue) ?: defaultValue
 
         sendFeatureFlagCalled(key, value)
 
@@ -751,7 +775,7 @@ public class PostHog private constructor(
         if (!isEnabled()) {
             return defaultValue
         }
-        val value = featureFlags?.getFeatureFlag(key, defaultValue) ?: defaultValue
+        val value = remoteConfig?.getFeatureFlag(key, defaultValue) ?: defaultValue
 
         sendFeatureFlagCalled(key, value)
 
@@ -765,7 +789,7 @@ public class PostHog private constructor(
         if (!isEnabled()) {
             return defaultValue
         }
-        return featureFlags?.getFeatureFlagPayload(key, defaultValue) ?: defaultValue
+        return remoteConfig?.getFeatureFlagPayload(key, defaultValue) ?: defaultValue
     }
 
     public override fun flush() {
@@ -790,7 +814,7 @@ public class PostHog private constructor(
             except.add(ANONYMOUS_ID)
         }
         getPreferences().clear(except = except.toList())
-        featureFlags?.clear()
+        remoteConfig?.clear()
         featureFlagsCalled.clear()
         synchronized(identifiedLock) {
             isIdentifiedLoaded = false
@@ -878,7 +902,7 @@ public class PostHog private constructor(
     // this is used in cases where we know the session is already active
     // so we spare another locker
     private fun isSessionReplayFlagActive(): Boolean {
-        return config?.sessionReplay == true && featureFlags?.isSessionReplayFlagActive() == true
+        return config?.sessionReplay == true && remoteConfig?.isSessionReplayFlagActive() == true
     }
 
     override fun isSessionReplayActive(): Boolean {

posthog/src/main/java/com/posthog/PostHogConfig.kt

@@ -50,6 +50,12 @@ public open class PostHogConfig(
      * Defaults to true
      */
     public var preloadFeatureFlags: Boolean = true,
+    /**
+     * Preload PostHog remote config automatically
+     * Defaults to true
+     */
+    @PostHogExperimental
+    public var remoteConfig: Boolean = true,
     /**
      * Number of minimum events before they are sent over the wire
      * Defaults to 20
@@ -212,6 +218,13 @@ public open class PostHogConfig(
     }
 
     public companion object {
-        public const val DEFAULT_HOST: String = "https://us.i.posthog.com"
+        public const val DEFAULT_US_HOST: String = "https://us.i.posthog.com"
+        public const val DEFAULT_US_ASSETS_HOST: String = "https://us-assets.i.posthog.com"
+
+        // flutter uses it
+        public const val DEFAULT_HOST: String = DEFAULT_US_HOST
+
+        public const val DEFAULT_EU_HOST: String = "https://eu.i.posthog.com"
+        public const val DEFAULT_EU_ASSETS_HOST: String = "https://eu-assets.i.posthog.com"
     }
 }

posthog/src/main/java/com/posthog/internal/PostHogApi.kt

@@ -1,6 +1,10 @@
 package com.posthog.internal
 
 import com.posthog.PostHogConfig
+import com.posthog.PostHogConfig.Companion.DEFAULT_EU_ASSETS_HOST
+import com.posthog.PostHogConfig.Companion.DEFAULT_EU_HOST
+import com.posthog.PostHogConfig.Companion.DEFAULT_US_ASSETS_HOST
+import com.posthog.PostHogConfig.Companion.DEFAULT_US_HOST
 import com.posthog.PostHogEvent
 import okhttp3.MediaType.Companion.toMediaType
 import okhttp3.OkHttpClient
@@ -17,10 +21,14 @@ import java.io.OutputStream
 internal class PostHogApi(
     private val config: PostHogConfig,
 ) {
+    private companion object {
+        private const val APP_JSON_UTF_8 = "application/json; charset=utf-8"
+    }
+
     private val mediaType by lazy {
         try {
             // can throw IllegalArgumentException
-            "application/json; charset=utf-8".toMediaType()
+            APP_JSON_UTF_8.toMediaType()
         } catch (ignored: Throwable) {
             null
         }
@@ -117,4 +125,38 @@ internal class PostHogApi(
             return null
         }
     }
+
+    @Throws(PostHogApiError::class, IOException::class)
+    fun remoteConfig(): PostHogRemoteConfigResponse? {
+        var host = theHost
+        host =
+            when (host) {
+                DEFAULT_US_HOST -> {
+                    DEFAULT_US_ASSETS_HOST
+                }
+                DEFAULT_EU_HOST -> {
+                    DEFAULT_EU_ASSETS_HOST
+                }
+                else -> {
+                    host
+                }
+            }
+
+        val request =
+            Request.Builder()
+                .url("$host/array/${config.apiKey}/config")
+                .header("User-Agent", config.userAgent)
+                .header("Content-Type", APP_JSON_UTF_8)
+                .get()
+                .build()
+
+        client.newCall(request).execute().use {
+            if (!it.isSuccessful) throw PostHogApiError(it.code, it.message, it.body)
+
+            it.body?.let { body ->
+                return config.serializer.deserialize(body.charStream().buffered())
+            }
+            return null
+        }
+    }
 }

posthog/src/main/java/com/posthog/internal/PostHogDecideResponse.kt

@@ -15,7 +15,5 @@ internal data class PostHogDecideResponse(
     val errorsWhileComputingFlags: Boolean = false,
     val featureFlags: Map<String, Any>?,
     val featureFlagPayloads: Map<String, Any?>?,
-    // its either a boolean or a map, see https://github.com/PostHog/posthog-js/blob/10fd7f4fa083f997d31a4a4c7be7d311d0a95e74/src/types.ts#L235-L243
-    val sessionRecording: Any? = false,
     val quotaLimited: List<String>? = null,
-)
+) : PostHogRemoteConfigResponse()