diff --git a/firebase-config/CHANGELOG.md b/firebase-config/CHANGELOG.md
index edf65709ccd..29ca82b2238 100644
--- a/firebase-config/CHANGELOG.md
+++ b/firebase-config/CHANGELOG.md
@@ -1,5 +1,5 @@
 # Unreleased
-
+* [feature] Added support for custom signal targeting in Remote Config. Use `setCustomSignals` API for setting custom signals and use them to build custom targeting conditions in Remote Config.
 
 # 22.0.1
 * [changed] Updated protobuf dependency to `3.25.5` to fix
diff --git a/firebase-config/api.txt b/firebase-config/api.txt
index 61528ec5d11..58e75c9e18c 100644
--- a/firebase-config/api.txt
+++ b/firebase-config/api.txt
@@ -16,6 +16,17 @@ package com.google.firebase.remoteconfig {
     method public void remove();
   }
 
+  public class CustomSignals {
+  }
+
+  public static class CustomSignals.Builder {
+    ctor public CustomSignals.Builder();
+    method @NonNull public com.google.firebase.remoteconfig.CustomSignals build();
+    method @NonNull public com.google.firebase.remoteconfig.CustomSignals.Builder put(@NonNull String, @Nullable String);
+    method @NonNull public com.google.firebase.remoteconfig.CustomSignals.Builder put(@NonNull String, long);
+    method @NonNull public com.google.firebase.remoteconfig.CustomSignals.Builder put(@NonNull String, double);
+  }
+
   public class FirebaseRemoteConfig {
     method @NonNull public com.google.android.gms.tasks.Task<java.lang.Boolean> activate();
     method @NonNull public com.google.firebase.remoteconfig.ConfigUpdateListenerRegistration addOnConfigUpdateListener(@NonNull com.google.firebase.remoteconfig.ConfigUpdateListener);
@@ -35,6 +46,7 @@ package com.google.firebase.remoteconfig {
     method @NonNull public com.google.firebase.remoteconfig.FirebaseRemoteConfigValue getValue(@NonNull String);
     method @NonNull public com.google.android.gms.tasks.Task<java.lang.Void> reset();
     method @NonNull public com.google.android.gms.tasks.Task<java.lang.Void> setConfigSettingsAsync(@NonNull com.google.firebase.remoteconfig.FirebaseRemoteConfigSettings);
+    method @NonNull public com.google.android.gms.tasks.Task<java.lang.Void> setCustomSignals(@NonNull com.google.firebase.remoteconfig.CustomSignals);
     method @NonNull public com.google.android.gms.tasks.Task<java.lang.Void> setDefaultsAsync(@NonNull java.util.Map<java.lang.String,java.lang.Object>);
     method @NonNull public com.google.android.gms.tasks.Task<java.lang.Void> setDefaultsAsync(@XmlRes int);
     field public static final boolean DEFAULT_VALUE_FOR_BOOLEAN = false;
@@ -121,6 +133,7 @@ package com.google.firebase.remoteconfig {
   }
 
   public final class RemoteConfigKt {
+    method @NonNull public static com.google.firebase.remoteconfig.CustomSignals customSignals(@NonNull kotlin.jvm.functions.Function1<? super com.google.firebase.remoteconfig.CustomSignals.Builder,kotlin.Unit> builder);
     method @NonNull public static operator com.google.firebase.remoteconfig.FirebaseRemoteConfigValue get(@NonNull com.google.firebase.remoteconfig.FirebaseRemoteConfig, @NonNull String key);
     method @NonNull public static kotlinx.coroutines.flow.Flow<com.google.firebase.remoteconfig.ConfigUpdate> getConfigUpdates(@NonNull com.google.firebase.remoteconfig.FirebaseRemoteConfig);
     method @NonNull public static com.google.firebase.remoteconfig.FirebaseRemoteConfig getRemoteConfig(@NonNull com.google.firebase.Firebase);
diff --git a/firebase-config/ktx/src/test/kotlin/com/google/firebase/remoteconfig/TestConstructorUtil.kt b/firebase-config/ktx/src/test/kotlin/com/google/firebase/remoteconfig/TestConstructorUtil.kt
index e6167b5ab09..4c153bff1e3 100644
--- a/firebase-config/ktx/src/test/kotlin/com/google/firebase/remoteconfig/TestConstructorUtil.kt
+++ b/firebase-config/ktx/src/test/kotlin/com/google/firebase/remoteconfig/TestConstructorUtil.kt
@@ -23,8 +23,8 @@ import com.google.firebase.installations.FirebaseInstallationsApi
 import com.google.firebase.remoteconfig.internal.ConfigCacheClient
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler
 import com.google.firebase.remoteconfig.internal.ConfigGetParameterHandler
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient
 import com.google.firebase.remoteconfig.internal.ConfigRealtimeHandler
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient
 import com.google.firebase.remoteconfig.internal.rollouts.RolloutsStateSubscriptionsHandler
 import java.util.concurrent.Executor
 
@@ -41,7 +41,7 @@ fun createRemoteConfig(
   defaultConfigsCache: ConfigCacheClient,
   fetchHandler: ConfigFetchHandler,
   getHandler: ConfigGetParameterHandler,
-  frcMetadata: ConfigMetadataClient,
+  frcSharedPrefs: ConfigSharedPrefsClient,
   realtimeHandler: ConfigRealtimeHandler,
   rolloutsStateSubscriptionsHandler: RolloutsStateSubscriptionsHandler
 ): FirebaseRemoteConfig {
@@ -56,7 +56,7 @@ fun createRemoteConfig(
     defaultConfigsCache,
     fetchHandler,
     getHandler,
-    frcMetadata,
+    frcSharedPrefs,
     realtimeHandler,
     rolloutsStateSubscriptionsHandler
   )
diff --git a/firebase-config/ktx/src/test/kotlin/com/google/firebase/remoteconfig/ktx/RemoteConfigTests.kt b/firebase-config/ktx/src/test/kotlin/com/google/firebase/remoteconfig/ktx/RemoteConfigTests.kt
index bb525cf4090..d3e7d10e725 100644
--- a/firebase-config/ktx/src/test/kotlin/com/google/firebase/remoteconfig/ktx/RemoteConfigTests.kt
+++ b/firebase-config/ktx/src/test/kotlin/com/google/firebase/remoteconfig/ktx/RemoteConfigTests.kt
@@ -32,8 +32,8 @@ import com.google.firebase.remoteconfig.createRemoteConfig
 import com.google.firebase.remoteconfig.internal.ConfigCacheClient
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler
 import com.google.firebase.remoteconfig.internal.ConfigGetParameterHandler
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient
 import com.google.firebase.remoteconfig.internal.ConfigRealtimeHandler
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient
 import com.google.firebase.remoteconfig.internal.rollouts.RolloutsStateSubscriptionsHandler
 import org.junit.After
 import org.junit.Before
@@ -142,7 +142,7 @@ class ConfigTests : BaseTestCase() {
         defaultConfigsCache = mock(ConfigCacheClient::class.java),
         fetchHandler = mock(ConfigFetchHandler::class.java),
         getHandler = mockGetHandler,
-        frcMetadata = mock(ConfigMetadataClient::class.java),
+        frcSharedPrefs = mock(ConfigSharedPrefsClient::class.java),
         realtimeHandler = mock(ConfigRealtimeHandler::class.java),
         rolloutsStateSubscriptionsHandler = mock(RolloutsStateSubscriptionsHandler::class.java)
       )
diff --git a/firebase-config/src/androidTest/java/com/google/firebase/remoteconfig/FirebaseRemoteConfigIntegrationTest.java b/firebase-config/src/androidTest/java/com/google/firebase/remoteconfig/FirebaseRemoteConfigIntegrationTest.java
index 19900986b6f..cc8c259836e 100644
--- a/firebase-config/src/androidTest/java/com/google/firebase/remoteconfig/FirebaseRemoteConfigIntegrationTest.java
+++ b/firebase-config/src/androidTest/java/com/google/firebase/remoteconfig/FirebaseRemoteConfigIntegrationTest.java
@@ -35,8 +35,8 @@
 import com.google.firebase.remoteconfig.internal.ConfigContainer;
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler;
 import com.google.firebase.remoteconfig.internal.ConfigGetParameterHandler;
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient;
 import com.google.firebase.remoteconfig.internal.ConfigRealtimeHandler;
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient;
 import com.google.firebase.remoteconfig.internal.rollouts.RolloutsStateSubscriptionsHandler;
 import java.util.Date;
 import java.util.HashMap;
@@ -60,7 +60,7 @@ public class FirebaseRemoteConfigIntegrationTest {
   @Mock private ConfigCacheClient mockDefaultsCache;
   @Mock private ConfigFetchHandler mockFetchHandler;
   @Mock private ConfigGetParameterHandler mockGetHandler;
-  @Mock private ConfigMetadataClient metadataClient;
+  @Mock private ConfigSharedPrefsClient sharedPrefsClient;
   @Mock private ConfigRealtimeHandler mockConfigRealtimeHandler;
   @Mock private RolloutsStateSubscriptionsHandler mockRolloutsStateSubscriptionHandler;
 
@@ -112,7 +112,7 @@ public void setUp() {
             mockDefaultsCache,
             mockFetchHandler,
             mockGetHandler,
-            metadataClient,
+            sharedPrefsClient,
             mockConfigRealtimeHandler,
             mockRolloutsStateSubscriptionHandler);
   }
diff --git a/firebase-config/src/main/java/com/google/firebase/remoteconfig/CustomSignals.java b/firebase-config/src/main/java/com/google/firebase/remoteconfig/CustomSignals.java
new file mode 100644
index 00000000000..78d8d6cc415
--- /dev/null
+++ b/firebase-config/src/main/java/com/google/firebase/remoteconfig/CustomSignals.java
@@ -0,0 +1,86 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.firebase.remoteconfig;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+import java.util.HashMap;
+import java.util.Map;
+
+/**
+ * A container type to represent key/value pairs of heterogeneous types to be set as custom signals
+ * in {@link FirebaseRemoteConfig#setCustomSignals}.
+ */
+public class CustomSignals {
+  final Map<String, String> customSignals;
+
+  /** Builder for constructing {@link CustomSignals} instances. */
+  public static class Builder {
+    private Map<String, String> customSignals = new HashMap<String, String>();
+
+    /**
+     * Adds a custom signal with a value that can be a string or null to the builder.
+     *
+     * @param key The key for the custom signal.
+     * @param value The string value associated with the key. Can be null.
+     * @return This Builder instance to allow chaining of method calls.
+     */
+    @NonNull
+    public Builder put(@NonNull String key, @Nullable String value) {
+      customSignals.put(key, value);
+      return this;
+    }
+
+    /**
+     * Adds a custom signal with a long value to the builder.
+     *
+     * @param key The key for the custom signal.
+     * @param value The long value for the custom signal.
+     * @return This Builder instance to allow chaining of method calls.
+     */
+    @NonNull
+    public Builder put(@NonNull String key, long value) {
+      customSignals.put(key, Long.toString(value));
+      return this;
+    }
+
+    /**
+     * Adds a custom signal with a double value to the builder.
+     *
+     * @param key The key for the custom signal.
+     * @param value The double value for the custom signal.
+     * @return This Builder instance to allow chaining of method calls.
+     */
+    @NonNull
+    public Builder put(@NonNull String key, double value) {
+      customSignals.put(key, Double.toString(value));
+      return this;
+    }
+
+    /**
+     * Creates a {@link CustomSignals} instance with the added custom signals.
+     *
+     * @return The constructed {@link CustomSignals} instance.
+     */
+    @NonNull
+    public CustomSignals build() {
+      return new CustomSignals(this);
+    }
+  }
+
+  CustomSignals(@NonNull Builder builder) {
+    this.customSignals = builder.customSignals;
+  }
+}
diff --git a/firebase-config/src/main/java/com/google/firebase/remoteconfig/FirebaseRemoteConfig.java b/firebase-config/src/main/java/com/google/firebase/remoteconfig/FirebaseRemoteConfig.java
index b2e7e73d954..808892e7521 100644
--- a/firebase-config/src/main/java/com/google/firebase/remoteconfig/FirebaseRemoteConfig.java
+++ b/firebase-config/src/main/java/com/google/firebase/remoteconfig/FirebaseRemoteConfig.java
@@ -33,8 +33,8 @@
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler;
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler.FetchResponse;
 import com.google.firebase.remoteconfig.internal.ConfigGetParameterHandler;
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient;
 import com.google.firebase.remoteconfig.internal.ConfigRealtimeHandler;
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient;
 import com.google.firebase.remoteconfig.internal.DefaultsXmlParser;
 import com.google.firebase.remoteconfig.internal.rollouts.RolloutsStateSubscriptionsHandler;
 import java.util.ArrayList;
@@ -160,7 +160,7 @@ public static FirebaseRemoteConfig getInstance(@NonNull FirebaseApp app) {
   private final ConfigCacheClient defaultConfigsCache;
   private final ConfigFetchHandler fetchHandler;
   private final ConfigGetParameterHandler getHandler;
-  private final ConfigMetadataClient frcMetadata;
+  private final ConfigSharedPrefsClient frcSharedPrefs;
   private final FirebaseInstallationsApi firebaseInstallations;
   private final ConfigRealtimeHandler configRealtimeHandler;
   private final RolloutsStateSubscriptionsHandler rolloutsStateSubscriptionsHandler;
@@ -181,7 +181,7 @@ public static FirebaseRemoteConfig getInstance(@NonNull FirebaseApp app) {
       ConfigCacheClient defaultConfigsCache,
       ConfigFetchHandler fetchHandler,
       ConfigGetParameterHandler getHandler,
-      ConfigMetadataClient frcMetadata,
+      ConfigSharedPrefsClient frcSharedPrefs,
       ConfigRealtimeHandler configRealtimeHandler,
       RolloutsStateSubscriptionsHandler rolloutsStateSubscriptionsHandler) {
     this.context = context;
@@ -194,7 +194,7 @@ public static FirebaseRemoteConfig getInstance(@NonNull FirebaseApp app) {
     this.defaultConfigsCache = defaultConfigsCache;
     this.fetchHandler = fetchHandler;
     this.getHandler = getHandler;
-    this.frcMetadata = frcMetadata;
+    this.frcSharedPrefs = frcSharedPrefs;
     this.configRealtimeHandler = configRealtimeHandler;
     this.rolloutsStateSubscriptionsHandler = rolloutsStateSubscriptionsHandler;
   }
@@ -208,7 +208,7 @@ public Task<FirebaseRemoteConfigInfo> ensureInitialized() {
     Task<ConfigContainer> activatedConfigsTask = activatedConfigsCache.get();
     Task<ConfigContainer> defaultsConfigsTask = defaultConfigsCache.get();
     Task<ConfigContainer> fetchedConfigsTask = fetchedConfigsCache.get();
-    Task<FirebaseRemoteConfigInfo> metadataTask = Tasks.call(executor, this::getInfo);
+    Task<FirebaseRemoteConfigInfo> sharedPrefsTask = Tasks.call(executor, this::getInfo);
     Task<String> installationIdTask = firebaseInstallations.getId();
     Task<InstallationTokenResult> installationTokenTask = firebaseInstallations.getToken(false);
 
@@ -216,10 +216,10 @@ public Task<FirebaseRemoteConfigInfo> ensureInitialized() {
             activatedConfigsTask,
             defaultsConfigsTask,
             fetchedConfigsTask,
-            metadataTask,
+            sharedPrefsTask,
             installationIdTask,
             installationTokenTask)
-        .continueWith(executor, (unusedListOfCompletedTasks) -> metadataTask.getResult());
+        .continueWith(executor, (unusedListOfCompletedTasks) -> sharedPrefsTask.getResult());
   }
 
   /**
@@ -475,7 +475,7 @@ public Map<String, FirebaseRemoteConfigValue> getAll() {
    */
   @NonNull
   public FirebaseRemoteConfigInfo getInfo() {
-    return frcMetadata.getInfo();
+    return frcSharedPrefs.getInfo();
   }
 
   /**
@@ -488,7 +488,7 @@ public Task<Void> setConfigSettingsAsync(@NonNull FirebaseRemoteConfigSettings s
     return Tasks.call(
         executor,
         () -> {
-          frcMetadata.setConfigSettings(settings);
+          frcSharedPrefs.setConfigSettings(settings);
 
           // Return value required; return null for Void.
           return null;
@@ -548,14 +548,14 @@ public Task<Void> setDefaultsAsync(@XmlRes int resourceId) {
   @NonNull
   public Task<Void> reset() {
     // Use a Task to avoid throwing potential file I/O errors to the caller and because
-    // frcMetadata's clear call is blocking.
+    // frcSharedPrefs's clear call is blocking.
     return Tasks.call(
         executor,
         () -> {
           activatedConfigsCache.clear();
           fetchedConfigsCache.clear();
           defaultConfigsCache.clear();
-          frcMetadata.clear();
+          frcSharedPrefs.clear();
           return null;
         });
   }
@@ -652,6 +652,30 @@ private Task<Void> setDefaultsWithStringsMapAsync(Map<String, String> defaultsSt
         FirebaseExecutors.directExecutor(), (unusedContainer) -> Tasks.forResult(null));
   }
 
+  /**
+   * Asynchronously changes the custom signals for this {@link FirebaseRemoteConfig} instance.
+   *
+   * <p>Custom signals are subject to limits on the size of key/value pairs and the total
+   * number of signals. Any calls that exceed these limits will be discarded.
+   *
+   * @param customSignals The custom signals to set for this instance.
+   * <ol>
+   *   <li>New keys will add new key-value pairs in the custom signals.
+   *   <li>Existing keys with new values will update the corresponding signals.
+   *   <li>Setting a key's value to {@code null} will remove the associated signal.
+   * </ol>
+   */
+  // TODO(b/385028620): Add link to documentation about custom signal limits.
+  @NonNull
+  public Task<Void> setCustomSignals(@NonNull CustomSignals customSignals) {
+    return Tasks.call(
+        executor,
+        () -> {
+          frcSharedPrefs.setCustomSignals(customSignals.customSignals);
+          return null;
+        });
+  }
+
   /**
    * Notifies the Firebase A/B Testing SDK about activated experiments.
    *
diff --git a/firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfig.kt b/firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfig.kt
index a944a7e8857..3a7ef220198 100644
--- a/firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfig.kt
+++ b/firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfig.kt
@@ -48,6 +48,9 @@ fun remoteConfigSettings(
   return builder.build()
 }
 
+fun customSignals(builder: CustomSignals.Builder.() -> Unit) =
+  CustomSignals.Builder().apply(builder).build()
+
 /**
  * Starts listening for config updates from the Remote Config backend and emits [ConfigUpdate]s via
  * a [Flow]. See [FirebaseRemoteConfig.addOnConfigUpdateListener] for more information.
diff --git a/firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfigComponent.java b/firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfigComponent.java
index 0835488f934..73fcec6e6c0 100644
--- a/firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfigComponent.java
+++ b/firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfigComponent.java
@@ -36,8 +36,8 @@
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler;
 import com.google.firebase.remoteconfig.internal.ConfigFetchHttpClient;
 import com.google.firebase.remoteconfig.internal.ConfigGetParameterHandler;
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient;
 import com.google.firebase.remoteconfig.internal.ConfigRealtimeHandler;
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient;
 import com.google.firebase.remoteconfig.internal.ConfigStorageClient;
 import com.google.firebase.remoteconfig.internal.Personalization;
 import com.google.firebase.remoteconfig.internal.rollouts.RolloutsStateFactory;
@@ -166,7 +166,7 @@ public synchronized FirebaseRemoteConfig get(String namespace) {
     ConfigCacheClient fetchedCacheClient = getCacheClient(namespace, FETCH_FILE_NAME);
     ConfigCacheClient activatedCacheClient = getCacheClient(namespace, ACTIVATE_FILE_NAME);
     ConfigCacheClient defaultsCacheClient = getCacheClient(namespace, DEFAULTS_FILE_NAME);
-    ConfigMetadataClient metadataClient = getMetadataClient(context, appId, namespace);
+    ConfigSharedPrefsClient sharedPrefsClient = getSharedPrefsClient(context, appId, namespace);
 
     ConfigGetParameterHandler getHandler = getGetHandler(activatedCacheClient, defaultsCacheClient);
     Personalization personalization =
@@ -187,9 +187,9 @@ public synchronized FirebaseRemoteConfig get(String namespace) {
         fetchedCacheClient,
         activatedCacheClient,
         defaultsCacheClient,
-        getFetchHandler(namespace, fetchedCacheClient, metadataClient),
+        getFetchHandler(namespace, fetchedCacheClient, sharedPrefsClient),
         getHandler,
-        metadataClient,
+        sharedPrefsClient,
         rolloutsStateSubscriptionsHandler);
   }
 
@@ -206,7 +206,7 @@ synchronized FirebaseRemoteConfig get(
       ConfigCacheClient defaultsClient,
       ConfigFetchHandler fetchHandler,
       ConfigGetParameterHandler getHandler,
-      ConfigMetadataClient metadataClient,
+      ConfigSharedPrefsClient sharedPrefsClient,
       RolloutsStateSubscriptionsHandler rolloutsStateSubscriptionsHandler) {
     if (!frcNamespaceInstances.containsKey(namespace)) {
       FirebaseRemoteConfig in =
@@ -221,7 +221,7 @@ synchronized FirebaseRemoteConfig get(
               defaultsClient,
               fetchHandler,
               getHandler,
-              metadataClient,
+              sharedPrefsClient,
               getRealtime(
                   firebaseApp,
                   firebaseInstallations,
@@ -229,7 +229,7 @@ synchronized FirebaseRemoteConfig get(
                   activatedClient,
                   context,
                   namespace,
-                  metadataClient),
+                  sharedPrefsClient),
               rolloutsStateSubscriptionsHandler);
       in.startLoadingConfigsFromDisk();
       frcNamespaceInstances.put(namespace, in);
@@ -254,20 +254,22 @@ private ConfigCacheClient getCacheClient(String namespace, String configStoreTyp
 
   @VisibleForTesting
   ConfigFetchHttpClient getFrcBackendApiClient(
-      String apiKey, String namespace, ConfigMetadataClient metadataClient) {
+      String apiKey, String namespace, ConfigSharedPrefsClient sharedPrefsClient) {
     String appId = firebaseApp.getOptions().getApplicationId();
     return new ConfigFetchHttpClient(
         context,
         appId,
         apiKey,
         namespace,
-        /* connectTimeoutInSeconds= */ metadataClient.getFetchTimeoutInSeconds(),
-        /* readTimeoutInSeconds= */ metadataClient.getFetchTimeoutInSeconds());
+        /* connectTimeoutInSeconds= */ sharedPrefsClient.getFetchTimeoutInSeconds(),
+        /* readTimeoutInSeconds= */ sharedPrefsClient.getFetchTimeoutInSeconds());
   }
 
   @VisibleForTesting
   synchronized ConfigFetchHandler getFetchHandler(
-      String namespace, ConfigCacheClient fetchedCacheClient, ConfigMetadataClient metadataClient) {
+      String namespace,
+      ConfigCacheClient fetchedCacheClient,
+      ConfigSharedPrefsClient sharedPrefsClient) {
     return new ConfigFetchHandler(
         firebaseInstallations,
         isPrimaryApp(firebaseApp) ? analyticsConnector : () -> null,
@@ -275,8 +277,8 @@ synchronized ConfigFetchHandler getFetchHandler(
         DEFAULT_CLOCK,
         DEFAULT_RANDOM,
         fetchedCacheClient,
-        getFrcBackendApiClient(firebaseApp.getOptions().getApiKey(), namespace, metadataClient),
-        metadataClient,
+        getFrcBackendApiClient(firebaseApp.getOptions().getApiKey(), namespace, sharedPrefsClient),
+        sharedPrefsClient,
         this.customHeaders);
   }
 
@@ -287,7 +289,7 @@ synchronized ConfigRealtimeHandler getRealtime(
       ConfigCacheClient activatedCacheClient,
       Context context,
       String namespace,
-      ConfigMetadataClient metadataClient) {
+      ConfigSharedPrefsClient sharedPrefsClient) {
     return new ConfigRealtimeHandler(
         firebaseApp,
         firebaseInstallations,
@@ -295,7 +297,7 @@ synchronized ConfigRealtimeHandler getRealtime(
         activatedCacheClient,
         context,
         namespace,
-        metadataClient,
+        sharedPrefsClient,
         executor);
   }
 
@@ -305,13 +307,14 @@ private ConfigGetParameterHandler getGetHandler(
   }
 
   @VisibleForTesting
-  static ConfigMetadataClient getMetadataClient(Context context, String appId, String namespace) {
+  static ConfigSharedPrefsClient getSharedPrefsClient(
+      Context context, String appId, String namespace) {
     String fileName =
         String.format(
             "%s_%s_%s_%s",
             FIREBASE_REMOTE_CONFIG_FILE_NAME_PREFIX, appId, namespace, PREFERENCES_FILE_NAME);
     SharedPreferences preferences = context.getSharedPreferences(fileName, Context.MODE_PRIVATE);
-    return new ConfigMetadataClient(preferences);
+    return new ConfigSharedPrefsClient(preferences);
   }
 
   @Nullable
diff --git a/firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfigConstants.java b/firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfigConstants.java
index 9c1a352dd0a..410306afd9c 100644
--- a/firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfigConstants.java
+++ b/firebase-config/src/main/java/com/google/firebase/remoteconfig/RemoteConfigConstants.java
@@ -51,7 +51,8 @@ public final class RemoteConfigConstants {
     RequestFieldKey.PACKAGE_NAME,
     RequestFieldKey.SDK_VERSION,
     RequestFieldKey.ANALYTICS_USER_PROPERTIES,
-    RequestFieldKey.FIRST_OPEN_TIME
+    RequestFieldKey.FIRST_OPEN_TIME,
+    RequestFieldKey.CUSTOM_SIGNALS
   })
   @Retention(RetentionPolicy.SOURCE)
   public @interface RequestFieldKey {
@@ -68,6 +69,7 @@ public final class RemoteConfigConstants {
     String SDK_VERSION = "sdkVersion";
     String ANALYTICS_USER_PROPERTIES = "analyticsUserProperties";
     String FIRST_OPEN_TIME = "firstOpenTime";
+    String CUSTOM_SIGNALS = "customSignals";
   }
 
   /** Keys of fields in the Fetch response body from the Firebase Remote Config server. */
diff --git a/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigFetchHandler.java b/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigFetchHandler.java
index 7c98589b153..e130d13df49 100644
--- a/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigFetchHandler.java
+++ b/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigFetchHandler.java
@@ -14,7 +14,7 @@
 
 package com.google.firebase.remoteconfig.internal;
 
-import static com.google.firebase.remoteconfig.internal.ConfigMetadataClient.LAST_FETCH_TIME_NO_FETCH_YET;
+import static com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.LAST_FETCH_TIME_NO_FETCH_YET;
 import static java.net.HttpURLConnection.HTTP_BAD_GATEWAY;
 import static java.net.HttpURLConnection.HTTP_FORBIDDEN;
 import static java.net.HttpURLConnection.HTTP_GATEWAY_TIMEOUT;
@@ -43,7 +43,7 @@
 import com.google.firebase.remoteconfig.FirebaseRemoteConfigFetchThrottledException;
 import com.google.firebase.remoteconfig.FirebaseRemoteConfigServerException;
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler.FetchResponse.Status;
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient.BackoffMetadata;
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.BackoffMetadata;
 import java.lang.annotation.Retention;
 import java.lang.annotation.RetentionPolicy;
 import java.net.HttpURLConnection;
@@ -96,7 +96,7 @@ public class ConfigFetchHandler {
   private final Random randomGenerator;
   private final ConfigCacheClient fetchedConfigsCache;
   private final ConfigFetchHttpClient frcBackendApiClient;
-  private final ConfigMetadataClient frcMetadata;
+  private final ConfigSharedPrefsClient frcSharedPrefs;
 
   private final Map<String, String> customHttpHeaders;
 
@@ -109,7 +109,7 @@ public ConfigFetchHandler(
       Random randomGenerator,
       ConfigCacheClient fetchedConfigsCache,
       ConfigFetchHttpClient frcBackendApiClient,
-      ConfigMetadataClient frcMetadata,
+      ConfigSharedPrefsClient frcSharedPrefs,
       Map<String, String> customHttpHeaders) {
     this.firebaseInstallations = firebaseInstallations;
     this.analyticsConnector = analyticsConnector;
@@ -118,16 +118,16 @@ public ConfigFetchHandler(
     this.randomGenerator = randomGenerator;
     this.fetchedConfigsCache = fetchedConfigsCache;
     this.frcBackendApiClient = frcBackendApiClient;
-    this.frcMetadata = frcMetadata;
+    this.frcSharedPrefs = frcSharedPrefs;
     this.customHttpHeaders = customHttpHeaders;
   }
 
   /**
    * Calls {@link #fetch(long)} with the {@link
-   * ConfigMetadataClient#getMinimumFetchIntervalInSeconds()}.
+   * ConfigSharedPrefsClient#getMinimumFetchIntervalInSeconds()}.
    */
   public Task<FetchResponse> fetch() {
-    return fetch(frcMetadata.getMinimumFetchIntervalInSeconds());
+    return fetch(frcSharedPrefs.getMinimumFetchIntervalInSeconds());
   }
 
   /**
@@ -228,7 +228,7 @@ public Task<FetchResponse> fetchNowWithTypeAndAttemptNumber(
    * currently throttled.
    *
    * <p>If a fetch request is made to the backend, updates the last fetch status, last successful
-   * fetch time and {@link BackoffMetadata} in {@link ConfigMetadataClient}.
+   * fetch time and {@link BackoffMetadata} in {@link ConfigSharedPrefsClient}.
    */
   private Task<FetchResponse> fetchIfCacheExpiredAndNotThrottled(
       Task<ConfigContainer> cachedFetchConfigsTask,
@@ -295,7 +295,7 @@ && areCachedFetchConfigsValid(minimumFetchIntervalInSeconds, currentTime)) {
    * on.
    */
   private boolean areCachedFetchConfigsValid(long cacheExpirationInSeconds, Date newFetchTime) {
-    Date lastSuccessfulFetchTime = frcMetadata.getLastSuccessfulFetchTime();
+    Date lastSuccessfulFetchTime = frcSharedPrefs.getLastSuccessfulFetchTime();
     // RC always fetches if the client has not previously had a successful fetch.
 
     if (lastSuccessfulFetchTime.equals(LAST_FETCH_TIME_NO_FETCH_YET)) {
@@ -315,7 +315,7 @@ private boolean areCachedFetchConfigsValid(long cacheExpirationInSeconds, Date n
    */
   @Nullable
   private Date getBackoffEndTimeInMillis(Date currentTime) {
-    Date backoffEndTime = frcMetadata.getBackoffMetadata().getBackoffEndTime();
+    Date backoffEndTime = frcSharedPrefs.getBackoffMetadata().getBackoffEndTime();
     if (currentTime.before(backoffEndTime)) {
       return backoffEndTime;
     }
@@ -381,21 +381,23 @@ private FetchResponse fetchFromBackend(
               installationId,
               installationToken,
               getUserProperties(),
-              frcMetadata.getLastFetchETag(),
+              frcSharedPrefs.getLastFetchETag(),
               customFetchHeaders,
               getFirstOpenTime(),
-              currentTime);
+              currentTime,
+              frcSharedPrefs.getCustomSignals());
 
       if (response.getFetchedConfigs() != null) {
         // Set template version in metadata to be saved on disk.
-        frcMetadata.setLastTemplateVersion(response.getFetchedConfigs().getTemplateVersionNumber());
+        frcSharedPrefs.setLastTemplateVersion(
+            response.getFetchedConfigs().getTemplateVersionNumber());
       }
       if (response.getLastFetchETag() != null) {
-        frcMetadata.setLastFetchETag(response.getLastFetchETag());
+        frcSharedPrefs.setLastFetchETag(response.getLastFetchETag());
       }
       // If the execute method did not throw exceptions, then the server sent a successful response
       // and the client can stop backing off.
-      frcMetadata.resetBackoff();
+      frcSharedPrefs.resetBackoff();
 
       return response;
     } catch (FirebaseRemoteConfigServerException serverHttpError) {
@@ -473,7 +475,7 @@ private BackoffMetadata updateAndReturnBackoffMetadata(int statusCode, Date curr
     if (isThrottleableServerError(statusCode)) {
       updateBackoffMetadataWithLastFailedFetchTime(currentTime);
     }
-    return frcMetadata.getBackoffMetadata();
+    return frcSharedPrefs.getBackoffMetadata();
   }
 
   /**
@@ -497,14 +499,14 @@ private boolean isThrottleableServerError(int httpStatusCode) {
    * disk-backed metadata.
    */
   private void updateBackoffMetadataWithLastFailedFetchTime(Date lastFailedFetchTime) {
-    int numFailedFetches = frcMetadata.getBackoffMetadata().getNumFailedFetches();
+    int numFailedFetches = frcSharedPrefs.getBackoffMetadata().getNumFailedFetches();
 
     numFailedFetches++;
 
     long backoffDurationInMillis = getRandomizedBackoffDurationInMillis(numFailedFetches);
     Date backoffEndTime = new Date(lastFailedFetchTime.getTime() + backoffDurationInMillis);
 
-    frcMetadata.setBackoffMetadata(numFailedFetches, backoffEndTime);
+    frcSharedPrefs.setBackoffMetadata(numFailedFetches, backoffEndTime);
   }
 
   /**
@@ -551,7 +553,7 @@ private boolean shouldThrottle(BackoffMetadata backoffMetadata, int httpStatusCo
   private void updateLastFetchStatusAndTime(
       Task<FetchResponse> completedFetchTask, Date fetchTime) {
     if (completedFetchTask.isSuccessful()) {
-      frcMetadata.updateLastFetchAsSuccessfulAt(fetchTime);
+      frcSharedPrefs.updateLastFetchAsSuccessfulAt(fetchTime);
       return;
     }
 
@@ -562,9 +564,9 @@ private void updateLastFetchStatusAndTime(
     }
 
     if (fetchException instanceof FirebaseRemoteConfigFetchThrottledException) {
-      frcMetadata.updateLastFetchAsThrottled();
+      frcSharedPrefs.updateLastFetchAsThrottled();
     } else {
-      frcMetadata.updateLastFetchAsFailed();
+      frcSharedPrefs.updateLastFetchAsFailed();
     }
   }
 
@@ -602,7 +604,7 @@ private Long getFirstOpenTime() {
   }
 
   public long getTemplateVersionNumber() {
-    return frcMetadata.getLastTemplateVersion();
+    return frcSharedPrefs.getLastTemplateVersion();
   }
 
   /** Used to verify that the fetch handler is getting Analytics as expected. */
diff --git a/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigFetchHttpClient.java b/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigFetchHttpClient.java
index b1867347580..ab068ffc674 100644
--- a/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigFetchHttpClient.java
+++ b/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigFetchHttpClient.java
@@ -21,6 +21,7 @@
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.APP_ID;
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.APP_VERSION;
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.COUNTRY_CODE;
+import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.CUSTOM_SIGNALS;
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.FIRST_OPEN_TIME;
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.INSTANCE_ID;
 import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.INSTANCE_ID_TOKEN;
@@ -183,7 +184,8 @@ FetchResponse fetch(
       String lastFetchETag,
       Map<String, String> customHeaders,
       Long firstOpenTime,
-      Date currentTime)
+      Date currentTime,
+      Map<String, String> customSignalsMap)
       throws FirebaseRemoteConfigException {
     setUpUrlConnection(urlConnection, lastFetchETag, installationAuthToken, customHeaders);
 
@@ -192,7 +194,11 @@ FetchResponse fetch(
     try {
       byte[] requestBody =
           createFetchRequestBody(
-                  installationId, installationAuthToken, analyticsUserProperties, firstOpenTime)
+                  installationId,
+                  installationAuthToken,
+                  analyticsUserProperties,
+                  firstOpenTime,
+                  customSignalsMap)
               .toString()
               .getBytes("utf-8");
       setFetchRequestBody(urlConnection, requestBody);
@@ -303,7 +309,8 @@ private JSONObject createFetchRequestBody(
       String installationId,
       String installationAuthToken,
       Map<String, String> analyticsUserProperties,
-      Long firstOpenTime)
+      Long firstOpenTime,
+      Map<String, String> customSignalsMap)
       throws FirebaseRemoteConfigClientException {
     Map<String, Object> requestBodyMap = new HashMap<>();
 
@@ -347,6 +354,13 @@ private JSONObject createFetchRequestBody(
 
     requestBodyMap.put(ANALYTICS_USER_PROPERTIES, new JSONObject(analyticsUserProperties));
 
+    if (!customSignalsMap.isEmpty()) {
+      requestBodyMap.put(CUSTOM_SIGNALS, new JSONObject(customSignalsMap));
+
+      // Log the keys of the custom signals sent during fetch.
+      Log.d(TAG, "Keys of custom signals during fetch: " + customSignalsMap.keySet());
+    }
+
     if (firstOpenTime != null) {
       requestBodyMap.put(FIRST_OPEN_TIME, convertToISOString(firstOpenTime));
     }
diff --git a/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigRealtimeHandler.java b/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigRealtimeHandler.java
index 53f89a71e8c..5ed1135dfc7 100644
--- a/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigRealtimeHandler.java
+++ b/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigRealtimeHandler.java
@@ -39,7 +39,7 @@ public class ConfigRealtimeHandler {
   private final ConfigCacheClient activatedCacheClient;
   private final Context context;
   private final String namespace;
-  private final ConfigMetadataClient metadataClient;
+  private final ConfigSharedPrefsClient sharedPrefsClient;
   private final ScheduledExecutorService scheduledExecutorService;
 
   public ConfigRealtimeHandler(
@@ -49,7 +49,7 @@ public ConfigRealtimeHandler(
       ConfigCacheClient activatedCacheClient,
       Context context,
       String namespace,
-      ConfigMetadataClient metadataClient,
+      ConfigSharedPrefsClient sharedPrefsClient,
       ScheduledExecutorService scheduledExecutorService) {
 
     this.listeners = new LinkedHashSet<>();
@@ -62,7 +62,7 @@ public ConfigRealtimeHandler(
             context,
             namespace,
             listeners,
-            metadataClient,
+            sharedPrefsClient,
             scheduledExecutorService);
 
     this.firebaseApp = firebaseApp;
@@ -71,7 +71,7 @@ public ConfigRealtimeHandler(
     this.activatedCacheClient = activatedCacheClient;
     this.context = context;
     this.namespace = namespace;
-    this.metadataClient = metadataClient;
+    this.sharedPrefsClient = sharedPrefsClient;
     this.scheduledExecutorService = scheduledExecutorService;
   }
 
diff --git a/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigRealtimeHttpClient.java b/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigRealtimeHttpClient.java
index ef0ef2defc5..2c1c44480e2 100644
--- a/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigRealtimeHttpClient.java
+++ b/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigRealtimeHttpClient.java
@@ -110,7 +110,7 @@ public class ConfigRealtimeHttpClient {
   private final String namespace;
   private final Random random;
   private final Clock clock;
-  private final ConfigMetadataClient metadataClient;
+  private final ConfigSharedPrefsClient sharedPrefsClient;
 
   public ConfigRealtimeHttpClient(
       FirebaseApp firebaseApp,
@@ -120,7 +120,7 @@ public ConfigRealtimeHttpClient(
       Context context,
       String namespace,
       Set<ConfigUpdateListener> listeners,
-      ConfigMetadataClient metadataClient,
+      ConfigSharedPrefsClient sharedPrefsClient,
       ScheduledExecutorService scheduledExecutorService) {
 
     this.listeners = listeners;
@@ -132,7 +132,7 @@ public ConfigRealtimeHttpClient(
     // Retrieve number of remaining retries from last session. The minimum retry count being one.
     httpRetriesRemaining =
         Math.max(
-            ORIGINAL_RETRIES - metadataClient.getRealtimeBackoffMetadata().getNumFailedStreams(),
+            ORIGINAL_RETRIES - sharedPrefsClient.getRealtimeBackoffMetadata().getNumFailedStreams(),
             1);
     clock = DefaultClock.getInstance();
 
@@ -142,7 +142,7 @@ public ConfigRealtimeHttpClient(
     this.activatedCache = activatedCache;
     this.context = context;
     this.namespace = namespace;
-    this.metadataClient = metadataClient;
+    this.sharedPrefsClient = sharedPrefsClient;
     this.isRealtimeDisabled = false;
     this.isInBackground = false;
   }
@@ -230,13 +230,13 @@ private synchronized void propagateErrors(FirebaseRemoteConfigException exceptio
   // Used for Tests only.
   @SuppressLint("VisibleForTests")
   public int getNumberOfFailedStreams() {
-    return metadataClient.getRealtimeBackoffMetadata().getNumFailedStreams();
+    return sharedPrefsClient.getRealtimeBackoffMetadata().getNumFailedStreams();
   }
 
   // Used for Tests only.
   @SuppressLint("VisibleForTests")
   public Date getBackoffEndTime() {
-    return metadataClient.getRealtimeBackoffMetadata().getBackoffEndTime();
+    return sharedPrefsClient.getRealtimeBackoffMetadata().getBackoffEndTime();
   }
 
   // TODO(issues/265): Make this an atomic operation within the Metadata class to avoid possible
@@ -248,7 +248,7 @@ public Date getBackoffEndTime() {
    */
   private void updateBackoffMetadataWithLastFailedStreamConnectionTime(
       Date lastFailedRealtimeStreamTime) {
-    int numFailedStreams = metadataClient.getRealtimeBackoffMetadata().getNumFailedStreams();
+    int numFailedStreams = sharedPrefsClient.getRealtimeBackoffMetadata().getNumFailedStreams();
 
     numFailedStreams++;
 
@@ -256,7 +256,7 @@ private void updateBackoffMetadataWithLastFailedStreamConnectionTime(
     Date backoffEndTime =
         new Date(lastFailedRealtimeStreamTime.getTime() + backoffDurationInMillis);
 
-    metadataClient.setRealtimeBackoffMetadata(numFailedStreams, backoffEndTime);
+    sharedPrefsClient.setRealtimeBackoffMetadata(numFailedStreams, backoffEndTime);
   }
 
   /**
@@ -362,7 +362,7 @@ public synchronized void retryHttpConnectionWhenBackoffEnds() {
     long retrySeconds =
         Math.max(
             0,
-            metadataClient.getRealtimeBackoffMetadata().getBackoffEndTime().getTime()
+            sharedPrefsClient.getRealtimeBackoffMetadata().getBackoffEndTime().getTime()
                 - currentTime.getTime());
     makeRealtimeHttpConnection(retrySeconds);
   }
@@ -473,8 +473,8 @@ public void beginRealtimeHttpStream() {
       return;
     }
 
-    ConfigMetadataClient.RealtimeBackoffMetadata backoffMetadata =
-        metadataClient.getRealtimeBackoffMetadata();
+    ConfigSharedPrefsClient.RealtimeBackoffMetadata backoffMetadata =
+        sharedPrefsClient.getRealtimeBackoffMetadata();
     Date currentTime = new Date(clock.currentTimeMillis());
     if (currentTime.before(backoffMetadata.getBackoffEndTime())) {
       retryHttpConnectionWhenBackoffEnds();
@@ -506,7 +506,7 @@ public void beginRealtimeHttpStream() {
                 if (responseCode == HttpURLConnection.HTTP_OK) {
                   // Reset the retries remaining if we opened the connection without an exception.
                   resetRetryCount();
-                  metadataClient.resetRealtimeBackoff();
+                  sharedPrefsClient.resetRealtimeBackoff();
 
                   // Start listening for realtime notifications.
                   ConfigAutoFetch configAutoFetch = startAutoFetch(httpURLConnection);
diff --git a/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigMetadataClient.java b/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigSharedPrefsClient.java
similarity index 65%
rename from firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigMetadataClient.java
rename to firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigSharedPrefsClient.java
index dddcb24bdb8..7ce24bc44f6 100644
--- a/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigMetadataClient.java
+++ b/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/ConfigSharedPrefsClient.java
@@ -18,11 +18,14 @@
 import static com.google.firebase.remoteconfig.FirebaseRemoteConfig.LAST_FETCH_STATUS_NO_FETCH_YET;
 import static com.google.firebase.remoteconfig.FirebaseRemoteConfig.LAST_FETCH_STATUS_SUCCESS;
 import static com.google.firebase.remoteconfig.FirebaseRemoteConfig.LAST_FETCH_STATUS_THROTTLED;
+import static com.google.firebase.remoteconfig.FirebaseRemoteConfig.TAG;
 import static com.google.firebase.remoteconfig.RemoteConfigComponent.CONNECTION_TIMEOUT_IN_SECONDS;
+import static com.google.firebase.remoteconfig.RemoteConfigConstants.RequestFieldKey.CUSTOM_SIGNALS;
 import static com.google.firebase.remoteconfig.internal.ConfigFetchHandler.DEFAULT_MINIMUM_FETCH_INTERVAL_IN_SECONDS;
 import static java.lang.annotation.RetentionPolicy.SOURCE;
 
 import android.content.SharedPreferences;
+import android.util.Log;
 import androidx.annotation.IntDef;
 import androidx.annotation.Nullable;
 import androidx.annotation.VisibleForTesting;
@@ -31,14 +34,20 @@
 import com.google.firebase.remoteconfig.FirebaseRemoteConfigSettings;
 import java.lang.annotation.Retention;
 import java.util.Date;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Objects;
+import org.json.JSONException;
+import org.json.JSONObject;
 
 /**
- * Client for handling Firebase Remote Config (FRC) metadata that is saved to disk and persisted
- * across App life cycles.
+ * Client for handling Firebase Remote Config (FRC) metadata and custom signals that are saved to
+ * disk and persisted across App life cycles.
  *
  * @author Miraziz Yusupov
  */
-public class ConfigMetadataClient {
+public class ConfigSharedPrefsClient {
   @Retention(SOURCE)
   @IntDef({
     LAST_FETCH_STATUS_SUCCESS,
@@ -75,65 +84,75 @@ public class ConfigMetadataClient {
   private static final String REALTIME_BACKOFF_END_TIME_IN_MILLIS_KEY =
       "realtime_backoff_end_time_in_millis";
 
-  private final SharedPreferences frcMetadata;
+  /** Constants for custom signal limits.*/
+  private static final int CUSTOM_SIGNALS_MAX_KEY_LENGTH = 250;
+
+  private static final int CUSTOM_SIGNALS_MAX_STRING_VALUE_LENGTH = 500;
+
+  private static final int CUSTOM_SIGNALS_MAX_COUNT = 100;
+
+  private final SharedPreferences frcSharedPrefs;
 
   private final Object frcInfoLock;
   private final Object backoffMetadataLock;
   private final Object realtimeBackoffMetadataLock;
+  private final Object customSignalsLock;
 
-  public ConfigMetadataClient(SharedPreferences frcMetadata) {
-    this.frcMetadata = frcMetadata;
+  public ConfigSharedPrefsClient(SharedPreferences frcSharedPrefs) {
+    this.frcSharedPrefs = frcSharedPrefs;
     this.frcInfoLock = new Object();
     this.backoffMetadataLock = new Object();
     this.realtimeBackoffMetadataLock = new Object();
+    this.customSignalsLock = new Object();
   }
 
   public long getFetchTimeoutInSeconds() {
-    return frcMetadata.getLong(FETCH_TIMEOUT_IN_SECONDS_KEY, CONNECTION_TIMEOUT_IN_SECONDS);
+    return frcSharedPrefs.getLong(FETCH_TIMEOUT_IN_SECONDS_KEY, CONNECTION_TIMEOUT_IN_SECONDS);
   }
 
   public long getMinimumFetchIntervalInSeconds() {
-    return frcMetadata.getLong(
+    return frcSharedPrefs.getLong(
         MINIMUM_FETCH_INTERVAL_IN_SECONDS_KEY, DEFAULT_MINIMUM_FETCH_INTERVAL_IN_SECONDS);
   }
 
   @LastFetchStatus
   int getLastFetchStatus() {
-    return frcMetadata.getInt(LAST_FETCH_STATUS_KEY, LAST_FETCH_STATUS_NO_FETCH_YET);
+    return frcSharedPrefs.getInt(LAST_FETCH_STATUS_KEY, LAST_FETCH_STATUS_NO_FETCH_YET);
   }
 
   Date getLastSuccessfulFetchTime() {
     return new Date(
-        frcMetadata.getLong(
+        frcSharedPrefs.getLong(
             LAST_SUCCESSFUL_FETCH_TIME_IN_MILLIS_KEY, LAST_FETCH_TIME_IN_MILLIS_NO_FETCH_YET));
   }
 
   @Nullable
   String getLastFetchETag() {
-    return frcMetadata.getString(LAST_FETCH_ETAG_KEY, null);
+    return frcSharedPrefs.getString(LAST_FETCH_ETAG_KEY, null);
   }
 
   long getLastTemplateVersion() {
-    return frcMetadata.getLong(LAST_TEMPLATE_VERSION, 0);
+    return frcSharedPrefs.getLong(LAST_TEMPLATE_VERSION, 0);
   }
 
   public FirebaseRemoteConfigInfo getInfo() {
     // A lock is used here to prevent the setters in this class from changing the state of
-    // frcMetadata during a getInfo call.
+    // frcSharedPrefs during a getInfo call.
     synchronized (frcInfoLock) {
       long lastSuccessfulFetchTimeInMillis =
-          frcMetadata.getLong(
+          frcSharedPrefs.getLong(
               LAST_SUCCESSFUL_FETCH_TIME_IN_MILLIS_KEY, LAST_FETCH_TIME_IN_MILLIS_NO_FETCH_YET);
       @LastFetchStatus
       int lastFetchStatus =
-          frcMetadata.getInt(LAST_FETCH_STATUS_KEY, LAST_FETCH_STATUS_NO_FETCH_YET);
+          frcSharedPrefs.getInt(LAST_FETCH_STATUS_KEY, LAST_FETCH_STATUS_NO_FETCH_YET);
 
       FirebaseRemoteConfigSettings settings =
           new FirebaseRemoteConfigSettings.Builder()
               .setFetchTimeoutInSeconds(
-                  frcMetadata.getLong(FETCH_TIMEOUT_IN_SECONDS_KEY, CONNECTION_TIMEOUT_IN_SECONDS))
+                  frcSharedPrefs.getLong(
+                      FETCH_TIMEOUT_IN_SECONDS_KEY, CONNECTION_TIMEOUT_IN_SECONDS))
               .setMinimumFetchIntervalInSeconds(
-                  frcMetadata.getLong(
+                  frcSharedPrefs.getLong(
                       MINIMUM_FETCH_INTERVAL_IN_SECONDS_KEY,
                       DEFAULT_MINIMUM_FETCH_INTERVAL_IN_SECONDS))
               .build();
@@ -147,14 +166,14 @@ public FirebaseRemoteConfigInfo getInfo() {
   }
 
   /**
-   * Clears all metadata values from memory and disk.
+   * Clears all metadata and custom signals values from memory and disk.
    *
    * <p>The method is blocking and returns only when the values in disk are also cleared.
    */
   @WorkerThread
   public void clear() {
     synchronized (frcInfoLock) {
-      frcMetadata.edit().clear().commit();
+      frcSharedPrefs.edit().clear().commit();
     }
   }
 
@@ -167,7 +186,7 @@ public void clear() {
   @WorkerThread
   public void setConfigSettings(FirebaseRemoteConfigSettings settings) {
     synchronized (frcInfoLock) {
-      frcMetadata
+      frcSharedPrefs
           .edit()
           .putLong(FETCH_TIMEOUT_IN_SECONDS_KEY, settings.getFetchTimeoutInSeconds())
           .putLong(
@@ -184,7 +203,7 @@ public void setConfigSettings(FirebaseRemoteConfigSettings settings) {
    */
   public void setConfigSettingsWithoutWaitingOnDiskWrite(FirebaseRemoteConfigSettings settings) {
     synchronized (frcInfoLock) {
-      frcMetadata
+      frcSharedPrefs
           .edit()
           .putLong(FETCH_TIMEOUT_IN_SECONDS_KEY, settings.getFetchTimeoutInSeconds())
           .putLong(
@@ -195,7 +214,7 @@ public void setConfigSettingsWithoutWaitingOnDiskWrite(FirebaseRemoteConfigSetti
 
   void updateLastFetchAsSuccessfulAt(Date fetchTime) {
     synchronized (frcInfoLock) {
-      frcMetadata
+      frcSharedPrefs
           .edit()
           .putInt(LAST_FETCH_STATUS_KEY, LAST_FETCH_STATUS_SUCCESS)
           .putLong(LAST_SUCCESSFUL_FETCH_TIME_IN_MILLIS_KEY, fetchTime.getTime())
@@ -205,25 +224,25 @@ void updateLastFetchAsSuccessfulAt(Date fetchTime) {
 
   void updateLastFetchAsFailed() {
     synchronized (frcInfoLock) {
-      frcMetadata.edit().putInt(LAST_FETCH_STATUS_KEY, LAST_FETCH_STATUS_FAILURE).apply();
+      frcSharedPrefs.edit().putInt(LAST_FETCH_STATUS_KEY, LAST_FETCH_STATUS_FAILURE).apply();
     }
   }
 
   void updateLastFetchAsThrottled() {
     synchronized (frcInfoLock) {
-      frcMetadata.edit().putInt(LAST_FETCH_STATUS_KEY, LAST_FETCH_STATUS_THROTTLED).apply();
+      frcSharedPrefs.edit().putInt(LAST_FETCH_STATUS_KEY, LAST_FETCH_STATUS_THROTTLED).apply();
     }
   }
 
   void setLastFetchETag(String eTag) {
     synchronized (frcInfoLock) {
-      frcMetadata.edit().putString(LAST_FETCH_ETAG_KEY, eTag).apply();
+      frcSharedPrefs.edit().putString(LAST_FETCH_ETAG_KEY, eTag).apply();
     }
   }
 
   void setLastTemplateVersion(long templateVersion) {
     synchronized (frcInfoLock) {
-      frcMetadata.edit().putLong(LAST_TEMPLATE_VERSION, templateVersion).apply();
+      frcSharedPrefs.edit().putLong(LAST_TEMPLATE_VERSION, templateVersion).apply();
     }
   }
 
@@ -234,14 +253,15 @@ void setLastTemplateVersion(long templateVersion) {
   BackoffMetadata getBackoffMetadata() {
     synchronized (backoffMetadataLock) {
       return new BackoffMetadata(
-          frcMetadata.getInt(NUM_FAILED_FETCHES_KEY, NO_FAILED_FETCHES),
-          new Date(frcMetadata.getLong(BACKOFF_END_TIME_IN_MILLIS_KEY, NO_BACKOFF_TIME_IN_MILLIS)));
+          frcSharedPrefs.getInt(NUM_FAILED_FETCHES_KEY, NO_FAILED_FETCHES),
+          new Date(
+              frcSharedPrefs.getLong(BACKOFF_END_TIME_IN_MILLIS_KEY, NO_BACKOFF_TIME_IN_MILLIS)));
     }
   }
 
   void setBackoffMetadata(int numFailedFetches, Date backoffEndTime) {
     synchronized (backoffMetadataLock) {
-      frcMetadata
+      frcSharedPrefs
           .edit()
           .putInt(NUM_FAILED_FETCHES_KEY, numFailedFetches)
           .putLong(BACKOFF_END_TIME_IN_MILLIS_KEY, backoffEndTime.getTime())
@@ -249,6 +269,77 @@ void setBackoffMetadata(int numFailedFetches, Date backoffEndTime) {
     }
   }
 
+  public void setCustomSignals(Map<String, String> newCustomSignals) {
+    synchronized (customSignalsLock) {
+      // Retrieve existing custom signals
+      Map<String, String> existingCustomSignals = getCustomSignals();
+      // Tracks whether the custom signals have been modified.
+      boolean modified = false;
+
+      for (Map.Entry<String, String> entry : newCustomSignals.entrySet()) {
+        String key = entry.getKey();
+        String value = entry.getValue();
+
+        // Validate key and value length
+        if (key.length() > CUSTOM_SIGNALS_MAX_KEY_LENGTH
+            || (value != null && value.length() > CUSTOM_SIGNALS_MAX_STRING_VALUE_LENGTH)) {
+          Log.w(
+              TAG,
+              String.format(
+                  "Invalid custom signal: Custom signal keys must be %d characters or less, and values must be %d characters or less.",
+                  CUSTOM_SIGNALS_MAX_KEY_LENGTH, CUSTOM_SIGNALS_MAX_STRING_VALUE_LENGTH));
+          return;
+        }
+
+        // Merge new signals with existing ones, overwriting existing keys.
+        // Also, remove entries where the new value is null.
+        if (value != null) {
+          modified |= !Objects.equals(existingCustomSignals.put(key, value), value);
+        } else {
+          modified |= existingCustomSignals.remove(key) != null;
+        }
+      }
+
+      // Check if the map has actually changed and the size limit
+      if (!modified) {
+        return;
+      }
+      if (existingCustomSignals.size() > CUSTOM_SIGNALS_MAX_COUNT) {
+        Log.w(
+            TAG,
+            String.format(
+                "Invalid custom signal: Too many custom signals provided. The maximum allowed is %d.",
+                CUSTOM_SIGNALS_MAX_COUNT));
+        return;
+      }
+
+      frcSharedPrefs
+          .edit()
+          .putString(CUSTOM_SIGNALS, new JSONObject(existingCustomSignals).toString())
+          .commit();
+
+      // Log the keys of the updated custom signals.
+      Log.d(TAG, "Keys of updated custom signals: " + getCustomSignals().keySet());
+    }
+  }
+
+  public Map<String, String> getCustomSignals() {
+    String jsonString = frcSharedPrefs.getString(CUSTOM_SIGNALS, "{}");
+    try {
+      JSONObject existingCustomSignalsJson = new JSONObject(jsonString);
+      Map<String, String> custom_signals = new HashMap<>();
+      Iterator<String> keys = existingCustomSignalsJson.keys();
+      while (keys.hasNext()) {
+        String key = keys.next();
+        String value = existingCustomSignalsJson.optString(key);
+        custom_signals.put(key, value);
+      }
+      return custom_signals;
+    } catch (JSONException e) {
+      return new HashMap<>();
+    }
+  }
+
   void resetBackoff() {
     setBackoffMetadata(NO_FAILED_FETCHES, NO_BACKOFF_TIME);
   }
@@ -286,16 +377,16 @@ Date getBackoffEndTime() {
   public RealtimeBackoffMetadata getRealtimeBackoffMetadata() {
     synchronized (realtimeBackoffMetadataLock) {
       return new RealtimeBackoffMetadata(
-          frcMetadata.getInt(NUM_FAILED_REALTIME_STREAMS_KEY, NO_FAILED_REALTIME_STREAMS),
+          frcSharedPrefs.getInt(NUM_FAILED_REALTIME_STREAMS_KEY, NO_FAILED_REALTIME_STREAMS),
           new Date(
-              frcMetadata.getLong(
+              frcSharedPrefs.getLong(
                   REALTIME_BACKOFF_END_TIME_IN_MILLIS_KEY, NO_BACKOFF_TIME_IN_MILLIS)));
     }
   }
 
   void setRealtimeBackoffMetadata(int numFailedStreams, Date backoffEndTime) {
     synchronized (realtimeBackoffMetadataLock) {
-      frcMetadata
+      frcSharedPrefs
           .edit()
           .putInt(NUM_FAILED_REALTIME_STREAMS_KEY, numFailedStreams)
           .putLong(REALTIME_BACKOFF_END_TIME_IN_MILLIS_KEY, backoffEndTime.getTime())
diff --git a/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/FirebaseRemoteConfigInfoImpl.java b/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/FirebaseRemoteConfigInfoImpl.java
index 15f0bb00028..4a16f7bf4e9 100644
--- a/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/FirebaseRemoteConfigInfoImpl.java
+++ b/firebase-config/src/main/java/com/google/firebase/remoteconfig/internal/FirebaseRemoteConfigInfoImpl.java
@@ -16,7 +16,7 @@
 
 import com.google.firebase.remoteconfig.FirebaseRemoteConfigInfo;
 import com.google.firebase.remoteconfig.FirebaseRemoteConfigSettings;
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient.LastFetchStatus;
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.LastFetchStatus;
 
 /**
  * Impl class for FirebaseRemoteConfigInfo.
diff --git a/firebase-config/src/test/java/com/google/firebase/remoteconfig/CustomSignalsTest.java b/firebase-config/src/test/java/com/google/firebase/remoteconfig/CustomSignalsTest.java
new file mode 100644
index 00000000000..cf97e17226e
--- /dev/null
+++ b/firebase-config/src/test/java/com/google/firebase/remoteconfig/CustomSignalsTest.java
@@ -0,0 +1,86 @@
+// Copyright 2024 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+//
+// You may obtain a copy of the License at
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.firebase.remoteconfig;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import com.google.common.collect.ImmutableMap;
+import java.util.HashMap;
+import java.util.Map;
+import org.junit.Test;
+
+/** Unit tests for the {@link CustomSignals}.*/
+public class CustomSignalsTest {
+  @Test
+  public void testCustomSignals_builderPutString() {
+    CustomSignals customSignals =
+        new CustomSignals.Builder().put("key1", "value1").put("key2", "value2").build();
+    Map<String, String> expectedSignals = ImmutableMap.of("key1", "value1", "key2", "value2");
+    assertThat(customSignals.customSignals).isEqualTo(expectedSignals);
+  }
+
+  @Test
+  public void testCustomSignals_builderPutLong() {
+    CustomSignals customSignals =
+        new CustomSignals.Builder().put("key1", 123L).put("key2", 456L).build();
+    Map<String, String> expectedSignals = ImmutableMap.of("key1", "123", "key2", "456");
+    assertThat(customSignals.customSignals).isEqualTo(expectedSignals);
+  }
+
+  @Test
+  public void testCustomSignals_builderPutDouble() {
+    CustomSignals customSignals =
+        new CustomSignals.Builder().put("key1", 12.34).put("key2", 56.78).build();
+    Map<String, String> expectedSignals = ImmutableMap.of("key1", "12.34", "key2", "56.78");
+    assertThat(customSignals.customSignals).isEqualTo(expectedSignals);
+  }
+
+  @Test
+  public void testCustomSignals_builderPutNullValue() {
+    CustomSignals customSignals = new CustomSignals.Builder().put("key1", null).build();
+    Map<String, String> expectedSignals = new HashMap<>();
+    expectedSignals.put("key1", null);
+    assertThat(customSignals.customSignals).isEqualTo(expectedSignals);
+  }
+
+  @Test
+  public void testCustomSignals_builderPutDuplicateKeys() {
+    CustomSignals customSignals =
+        new CustomSignals.Builder()
+            .put("key1", "value1")
+            .put("key1", "value2")
+            .put("key1", "value3")
+            .build();
+    Map<String, String> expectedSignals = ImmutableMap.of("key1", "value3");
+    assertThat(customSignals.customSignals).isEqualTo(expectedSignals);
+  }
+
+  @Test
+  public void testCustomSignals_builderPutMixedTypes() {
+    CustomSignals customSignals =
+        new CustomSignals.Builder()
+            .put("key1", "value1")
+            .put("key2", 123L)
+            .put("key3", 45.67)
+            .put("key4", null)
+            .build();
+    Map<String, String> expectedSignals = new HashMap<>();
+    expectedSignals.put("key1", "value1");
+    expectedSignals.put("key2", "123");
+    expectedSignals.put("key3", "45.67");
+    expectedSignals.put("key4", null);
+    assertThat(customSignals.customSignals).isEqualTo(expectedSignals);
+  }
+}
diff --git a/firebase-config/src/test/java/com/google/firebase/remoteconfig/FirebaseRemoteConfigTest.java b/firebase-config/src/test/java/com/google/firebase/remoteconfig/FirebaseRemoteConfigTest.java
index 81f292a4c2b..fffc439dc2b 100644
--- a/firebase-config/src/test/java/com/google/firebase/remoteconfig/FirebaseRemoteConfigTest.java
+++ b/firebase-config/src/test/java/com/google/firebase/remoteconfig/FirebaseRemoteConfigTest.java
@@ -72,9 +72,9 @@
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler;
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler.FetchResponse;
 import com.google.firebase.remoteconfig.internal.ConfigGetParameterHandler;
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient;
 import com.google.firebase.remoteconfig.internal.ConfigRealtimeHandler;
 import com.google.firebase.remoteconfig.internal.ConfigRealtimeHttpClient;
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient;
 import com.google.firebase.remoteconfig.internal.FakeHttpURLConnection;
 import com.google.firebase.remoteconfig.internal.Personalization;
 import com.google.firebase.remoteconfig.internal.rollouts.RolloutsStateSubscriptionsHandler;
@@ -155,7 +155,7 @@ public final class FirebaseRemoteConfigTest {
   @Mock private ConfigCacheClient mockDefaultsCache;
   @Mock private ConfigFetchHandler mockFetchHandler;
   @Mock private ConfigGetParameterHandler mockGetHandler;
-  @Mock private ConfigMetadataClient metadataClient;
+  @Mock private ConfigSharedPrefsClient sharedPrefsClient;
 
   @Mock private ConfigRealtimeHandler mockConfigRealtimeHandler;
   @Mock private ConfigAutoFetch mockConfigAutoFetch;
@@ -192,7 +192,7 @@ public final class FirebaseRemoteConfigTest {
   private ConfigContainer realtimeFetchedContainer;
   private ConfigAutoFetch configAutoFetch;
   private ConfigRealtimeHttpClient configRealtimeHttpClient;
-  private ConfigMetadataClient realtimeMetadataClient;
+  private ConfigSharedPrefsClient realtimeSharedPrefsClient;
 
   private FetchResponse firstFetchedContainerResponse;
 
@@ -240,7 +240,7 @@ public void setUp() throws Exception {
             mockDefaultsCache,
             mockFetchHandler,
             mockGetHandler,
-            metadataClient,
+            sharedPrefsClient,
             mockConfigRealtimeHandler,
             mockRolloutsStateSubscriptionsHandler);
 
@@ -259,7 +259,7 @@ public void setUp() throws Exception {
                 mockFireperfDefaultsCache,
                 mockFireperfFetchHandler,
                 mockFireperfGetHandler,
-                RemoteConfigComponent.getMetadataClient(context, APP_ID, FIREPERF_NAMESPACE),
+                RemoteConfigComponent.getSharedPrefsClient(context, APP_ID, FIREPERF_NAMESPACE),
                 mockRolloutsStateSubscriptionsHandler);
 
     personalizationFrc =
@@ -276,7 +276,8 @@ public void setUp() throws Exception {
                 mockDefaultsCache,
                 mockFetchHandler,
                 parameterHandler,
-                RemoteConfigComponent.getMetadataClient(context, APP_ID, PERSONALIZATION_NAMESPACE),
+                RemoteConfigComponent.getSharedPrefsClient(
+                    context, APP_ID, PERSONALIZATION_NAMESPACE),
                 mockRolloutsStateSubscriptionsHandler);
 
     firstFetchedContainer =
@@ -349,8 +350,9 @@ public void onError(@NonNull FirebaseRemoteConfigException error) {
             listeners,
             mockRetryListener,
             scheduledExecutorService);
-    realtimeMetadataClient =
-        new ConfigMetadataClient(context.getSharedPreferences("test_file", Context.MODE_PRIVATE));
+    realtimeSharedPrefsClient =
+        new ConfigSharedPrefsClient(
+            context.getSharedPreferences("test_file", Context.MODE_PRIVATE));
     configRealtimeHttpClient =
         new ConfigRealtimeHttpClient(
             firebaseApp,
@@ -360,7 +362,7 @@ public void onError(@NonNull FirebaseRemoteConfigException error) {
             context,
             "firebase",
             listeners,
-            realtimeMetadataClient,
+            realtimeSharedPrefsClient,
             scheduledExecutorService);
   }
 
@@ -1024,7 +1026,7 @@ public void getLong_fireperfNamespace_keyExists_returnsRemoteValue() {
 
   @Test
   public void getInfo_returnsInfo() {
-    when(metadataClient.getInfo()).thenReturn(mockFrcInfo);
+    when(sharedPrefsClient.getInfo()).thenReturn(mockFrcInfo);
 
     long fetchTimeInMillis = 100L;
     int lastFetchStatus = LAST_FETCH_STATUS_THROTTLED;
@@ -1071,11 +1073,11 @@ public void clear_hasSettings_clearsEverything() {
     verify(mockActivatedCache).clear();
     verify(mockFetchedCache).clear();
     verify(mockDefaultsCache).clear();
-    verify(metadataClient).clear();
+    verify(sharedPrefsClient).clear();
   }
 
   @Test
-  public void setConfigSettingsAsync_updatesMetadata() {
+  public void setConfigSettingsAsync_updatesSharedPrefs() {
     long fetchTimeout = 13L;
     long minimumFetchInterval = 666L;
     FirebaseRemoteConfigSettings frcSettings =
@@ -1087,7 +1089,7 @@ public void setConfigSettingsAsync_updatesMetadata() {
     Task<Void> setterTask = frc.setConfigSettingsAsync(frcSettings);
 
     assertThat(setterTask.isSuccessful()).isTrue();
-    verify(metadataClient).setConfigSettings(frcSettings);
+    verify(sharedPrefsClient).setConfigSettings(frcSettings);
   }
 
   @Test
@@ -1658,6 +1660,22 @@ public void realtimeRequest_setRequestParams_succeedsWithCorrectParams() throws
     assertThat(fakeConnection.getRequestMethod()).isEqualTo("POST");
   }
 
+  @Test
+  public void setCustomSignals_succeeds_and_calls_sharedPrefsClient() {
+    CustomSignals customSignals =
+        new CustomSignals.Builder()
+            .put("key1", "value1")
+            .put("key2", 123L)
+            .put("key3", 12.34)
+            .put("key4", null)
+            .build();
+
+    Task<Void> setterTask = frc.setCustomSignals(customSignals);
+
+    assertThat(setterTask.isSuccessful()).isTrue();
+    verify(sharedPrefsClient).setCustomSignals(customSignals.customSignals);
+  }
+
   private static void loadCacheWithConfig(
       ConfigCacheClient cacheClient, ConfigContainer container) {
     when(cacheClient.getBlocking()).thenReturn(container);
diff --git a/firebase-config/src/test/java/com/google/firebase/remoteconfig/RemoteConfigComponentTest.java b/firebase-config/src/test/java/com/google/firebase/remoteconfig/RemoteConfigComponentTest.java
index c6869267a4d..e0ee9220855 100644
--- a/firebase-config/src/test/java/com/google/firebase/remoteconfig/RemoteConfigComponentTest.java
+++ b/firebase-config/src/test/java/com/google/firebase/remoteconfig/RemoteConfigComponentTest.java
@@ -39,7 +39,7 @@
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler;
 import com.google.firebase.remoteconfig.internal.ConfigFetchHttpClient;
 import com.google.firebase.remoteconfig.internal.ConfigGetParameterHandler;
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient;
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient;
 import com.google.firebase.remoteconfig.internal.rollouts.RolloutsStateSubscriptionsHandler;
 import com.google.firebase.remoteconfig.interop.rollouts.RolloutsStateSubscriber;
 import java.util.Date;
@@ -73,7 +73,7 @@ public class RemoteConfigComponentTest {
   @Mock private ConfigCacheClient mockDefaultsCache;
   @Mock private ConfigFetchHandler mockFetchHandler;
   @Mock private ConfigGetParameterHandler mockGetParameterHandler;
-  @Mock private ConfigMetadataClient mockMetadataClient;
+  @Mock private ConfigSharedPrefsClient mockSharedPrefsClient;
   @Mock private RolloutsStateSubscriptionsHandler mockRolloutsStateSubscriptionsHandler;
 
   @Mock private RolloutsStateSubscriber mockRolloutsStateSubscriber;
@@ -82,7 +82,7 @@ public class RemoteConfigComponentTest {
   private ExecutorService directExecutor;
   private ScheduledExecutorService scheduledExecutorService;
   private FirebaseApp defaultApp;
-  private ConfigMetadataClient metadataClient;
+  private ConfigSharedPrefsClient sharedPrefsClient;
 
   @Before
   public void setUp() {
@@ -94,7 +94,8 @@ public void setUp() {
 
     defaultApp = initializeFirebaseApp(context);
 
-    metadataClient = RemoteConfigComponent.getMetadataClient(context, APP_ID, "personalization");
+    sharedPrefsClient =
+        RemoteConfigComponent.getSharedPrefsClient(context, APP_ID, "personalization");
 
     when(mockFirebaseApp.getOptions())
         .thenReturn(new FirebaseOptions.Builder().setApplicationId(APP_ID).build());
@@ -106,7 +107,7 @@ public void setUp() {
   public void frc2p_doesNotCallAbt() throws Exception {
 
     FirebaseRemoteConfig fireperfFrc =
-        getFrcInstanceFromComponentWithMetadataClient(
+        getFrcInstanceFromComponentWithSharedPrefsClient(
             getNewFrcComponent(), /* namespace= */ "fireperf");
     loadConfigsWithExperimentsForActivate();
 
@@ -123,7 +124,7 @@ public void frcNonMainFirebaseApp_doesNotCallAbt() throws Exception {
 
     when(mockFirebaseApp.getName()).thenReturn("secondary");
     FirebaseRemoteConfig frc =
-        getFrcInstanceFromComponentWithMetadataClient(
+        getFrcInstanceFromComponentWithSharedPrefsClient(
             getNewFrcComponentWithoutLoadingDefault(), DEFAULT_NAMESPACE);
     loadConfigsWithExperimentsForActivate();
 
@@ -139,7 +140,7 @@ public void getFetchHandler_nonMainFirebaseApp_doesNotUseAnalytics() {
 
     ConfigFetchHandler fetchHandler =
         getNewFrcComponent()
-            .getFetchHandler(DEFAULT_NAMESPACE, mockFetchedCache, mockMetadataClient);
+            .getFetchHandler(DEFAULT_NAMESPACE, mockFetchedCache, mockSharedPrefsClient);
 
     assertThat(fetchHandler.getAnalyticsConnector().get()).isNull();
   }
@@ -149,10 +150,12 @@ public void getFetchHandler_nonMainFirebaseApp_doesNotUseAnalytics() {
       getFrcBackendApiClient_fetchTimeoutIsNotSet_buildsConfigFetchHttpClientWithDefaultConnectionTimeout() {
 
     RemoteConfigComponent frcComponent = defaultApp.get(RemoteConfigComponent.class);
-    when(mockMetadataClient.getFetchTimeoutInSeconds()).thenReturn(CONNECTION_TIMEOUT_IN_SECONDS);
+    when(mockSharedPrefsClient.getFetchTimeoutInSeconds())
+        .thenReturn(CONNECTION_TIMEOUT_IN_SECONDS);
 
     ConfigFetchHttpClient frcBackendClient =
-        frcComponent.getFrcBackendApiClient(DUMMY_API_KEY, DEFAULT_NAMESPACE, mockMetadataClient);
+        frcComponent.getFrcBackendApiClient(
+            DUMMY_API_KEY, DEFAULT_NAMESPACE, mockSharedPrefsClient);
 
     int actualConnectTimeout = getConnectTimeoutInSeconds(frcBackendClient);
     int actualReadTimeout = getReadTimeoutInSeconds(frcBackendClient);
@@ -167,11 +170,12 @@ public void getFetchHandler_nonMainFirebaseApp_doesNotUseAnalytics() {
     RemoteConfigComponent frcComponent = defaultApp.get(RemoteConfigComponent.class);
 
     long customConnectionTimeoutInSeconds = 2 * CONNECTION_TIMEOUT_IN_SECONDS;
-    when(mockMetadataClient.getFetchTimeoutInSeconds())
+    when(mockSharedPrefsClient.getFetchTimeoutInSeconds())
         .thenReturn(customConnectionTimeoutInSeconds);
 
     ConfigFetchHttpClient frcBackendClient =
-        frcComponent.getFrcBackendApiClient(DUMMY_API_KEY, DEFAULT_NAMESPACE, mockMetadataClient);
+        frcComponent.getFrcBackendApiClient(
+            DUMMY_API_KEY, DEFAULT_NAMESPACE, mockSharedPrefsClient);
 
     int actualConnectTimeout = getConnectTimeoutInSeconds(frcBackendClient);
     int actualReadTimeout = getReadTimeoutInSeconds(frcBackendClient);
@@ -181,9 +185,9 @@ public void getFetchHandler_nonMainFirebaseApp_doesNotUseAnalytics() {
 
   @Test
   public void registerRolloutsStateSubscriber_firebaseNamespace_callsSubscriptionHandler() {
-    // Mock metadata client response since Realtime handler can't be mocked here.
-    when(mockMetadataClient.getRealtimeBackoffMetadata())
-        .thenReturn(new ConfigMetadataClient.RealtimeBackoffMetadata(0, new Date()));
+    // Mock shared preference client response since Realtime handler can't be mocked here.
+    when(mockSharedPrefsClient.getRealtimeBackoffMetadata())
+        .thenReturn(new ConfigSharedPrefsClient.RealtimeBackoffMetadata(0, new Date()));
 
     RemoteConfigComponent frcComponent = getNewFrcComponentWithoutLoadingDefault();
     FirebaseRemoteConfig instance = getFrcInstanceFromComponent(frcComponent, DEFAULT_NAMESPACE);
@@ -216,7 +220,7 @@ private RemoteConfigComponent getNewFrcComponentWithoutLoadingDefault() {
         /* loadGetDefault= */ false);
   }
 
-  private FirebaseRemoteConfig getFrcInstanceFromComponentWithMetadataClient(
+  private FirebaseRemoteConfig getFrcInstanceFromComponentWithSharedPrefsClient(
       RemoteConfigComponent frcComponent, String namespace) {
     return frcComponent.get(
         mockFirebaseApp,
@@ -229,7 +233,7 @@ private FirebaseRemoteConfig getFrcInstanceFromComponentWithMetadataClient(
         mockDefaultsCache,
         mockFetchHandler,
         mockGetParameterHandler,
-        metadataClient,
+        sharedPrefsClient,
         mockRolloutsStateSubscriptionsHandler);
   }
 
@@ -246,7 +250,7 @@ private FirebaseRemoteConfig getFrcInstanceFromComponent(
         mockDefaultsCache,
         mockFetchHandler,
         mockGetParameterHandler,
-        mockMetadataClient,
+        mockSharedPrefsClient,
         mockRolloutsStateSubscriptionsHandler);
   }
 
diff --git a/firebase-config/src/test/java/com/google/firebase/remoteconfig/RemoteConfigTests.kt b/firebase-config/src/test/java/com/google/firebase/remoteconfig/RemoteConfigTests.kt
index 7624ee3827d..81cb8115661 100644
--- a/firebase-config/src/test/java/com/google/firebase/remoteconfig/RemoteConfigTests.kt
+++ b/firebase-config/src/test/java/com/google/firebase/remoteconfig/RemoteConfigTests.kt
@@ -29,8 +29,8 @@ import com.google.firebase.platforminfo.UserAgentPublisher
 import com.google.firebase.remoteconfig.internal.ConfigCacheClient
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler
 import com.google.firebase.remoteconfig.internal.ConfigGetParameterHandler
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient
 import com.google.firebase.remoteconfig.internal.ConfigRealtimeHandler
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient
 import com.google.firebase.remoteconfig.internal.rollouts.RolloutsStateSubscriptionsHandler
 import org.junit.After
 import org.junit.Before
@@ -139,7 +139,7 @@ class ConfigTests : BaseTestCase() {
         defaultConfigsCache = mock(ConfigCacheClient::class.java),
         fetchHandler = mock(ConfigFetchHandler::class.java),
         getHandler = mockGetHandler,
-        frcMetadata = mock(ConfigMetadataClient::class.java),
+        frcSharedPrefs = mock(ConfigSharedPrefsClient::class.java),
         realtimeHandler = mock(ConfigRealtimeHandler::class.java),
         rolloutsStateSubscriptionsHandler = mock(RolloutsStateSubscriptionsHandler::class.java)
       )
@@ -147,6 +147,19 @@ class ConfigTests : BaseTestCase() {
     `when`(mockGetHandler.getValue("KEY")).thenReturn(StringRemoteConfigValue("non default value"))
     assertThat(remoteConfig["KEY"].asString()).isEqualTo("non default value")
   }
+
+  @Test
+  fun `Custom Signals builder support multiple types`() {
+    val customSignals = customSignals {
+      put("key1", "value1")
+      put("key2", 123L)
+      put("key3", 45.67)
+      put("key4", null)
+    }
+    val expectedSignals =
+      mapOf("key1" to "value1", "key2" to "123", "key3" to "45.67", "key4" to null)
+    assertThat(customSignals.customSignals).isEqualTo(expectedSignals)
+  }
 }
 
 @RunWith(RobolectricTestRunner::class)
diff --git a/firebase-config/src/test/java/com/google/firebase/remoteconfig/TestConstructorUtil.kt b/firebase-config/src/test/java/com/google/firebase/remoteconfig/TestConstructorUtil.kt
index e6167b5ab09..4c153bff1e3 100644
--- a/firebase-config/src/test/java/com/google/firebase/remoteconfig/TestConstructorUtil.kt
+++ b/firebase-config/src/test/java/com/google/firebase/remoteconfig/TestConstructorUtil.kt
@@ -23,8 +23,8 @@ import com.google.firebase.installations.FirebaseInstallationsApi
 import com.google.firebase.remoteconfig.internal.ConfigCacheClient
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler
 import com.google.firebase.remoteconfig.internal.ConfigGetParameterHandler
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient
 import com.google.firebase.remoteconfig.internal.ConfigRealtimeHandler
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient
 import com.google.firebase.remoteconfig.internal.rollouts.RolloutsStateSubscriptionsHandler
 import java.util.concurrent.Executor
 
@@ -41,7 +41,7 @@ fun createRemoteConfig(
   defaultConfigsCache: ConfigCacheClient,
   fetchHandler: ConfigFetchHandler,
   getHandler: ConfigGetParameterHandler,
-  frcMetadata: ConfigMetadataClient,
+  frcSharedPrefs: ConfigSharedPrefsClient,
   realtimeHandler: ConfigRealtimeHandler,
   rolloutsStateSubscriptionsHandler: RolloutsStateSubscriptionsHandler
 ): FirebaseRemoteConfig {
@@ -56,7 +56,7 @@ fun createRemoteConfig(
     defaultConfigsCache,
     fetchHandler,
     getHandler,
-    frcMetadata,
+    frcSharedPrefs,
     realtimeHandler,
     rolloutsStateSubscriptionsHandler
   )
diff --git a/firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigFetchHandlerTest.java b/firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigFetchHandlerTest.java
index ed2781710fd..740a00191ec 100644
--- a/firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigFetchHandlerTest.java
+++ b/firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigFetchHandlerTest.java
@@ -29,9 +29,9 @@
 import static com.google.firebase.remoteconfig.internal.ConfigFetchHandler.DEFAULT_MINIMUM_FETCH_INTERVAL_IN_SECONDS;
 import static com.google.firebase.remoteconfig.internal.ConfigFetchHandler.FIRST_OPEN_TIME_KEY;
 import static com.google.firebase.remoteconfig.internal.ConfigFetchHandler.HTTP_TOO_MANY_REQUESTS;
-import static com.google.firebase.remoteconfig.internal.ConfigMetadataClient.LAST_FETCH_TIME_NO_FETCH_YET;
-import static com.google.firebase.remoteconfig.internal.ConfigMetadataClient.NO_BACKOFF_TIME;
-import static com.google.firebase.remoteconfig.internal.ConfigMetadataClient.NO_FAILED_FETCHES;
+import static com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.LAST_FETCH_TIME_NO_FETCH_YET;
+import static com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.NO_BACKOFF_TIME;
+import static com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.NO_FAILED_FETCHES;
 import static com.google.firebase.remoteconfig.testutil.Assert.assertThrows;
 import static java.net.HttpURLConnection.HTTP_BAD_GATEWAY;
 import static java.net.HttpURLConnection.HTTP_FORBIDDEN;
@@ -70,7 +70,7 @@
 import com.google.firebase.remoteconfig.FirebaseRemoteConfigServerException;
 import com.google.firebase.remoteconfig.FirebaseRemoteConfigSettings;
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler.FetchResponse;
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient.BackoffMetadata;
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.BackoffMetadata;
 import java.io.IOException;
 import java.net.HttpURLConnection;
 import java.net.URL;
@@ -127,7 +127,7 @@ public class ConfigFetchHandlerTest {
 
   private Context context;
   @Mock private FirebaseInstallationsApi mockFirebaseInstallations;
-  private ConfigMetadataClient metadataClient;
+  private ConfigSharedPrefsClient sharedPrefsClient;
 
   private ConfigFetchHandler fetchHandler;
 
@@ -142,8 +142,9 @@ public void setUp() throws Exception {
     directExecutor = MoreExecutors.directExecutor();
     context = ApplicationProvider.getApplicationContext();
     mockClock = new MockClock(0L);
-    metadataClient =
-        new ConfigMetadataClient(context.getSharedPreferences("test_file", Context.MODE_PRIVATE));
+    sharedPrefsClient =
+        new ConfigSharedPrefsClient(
+            context.getSharedPreferences("test_file", Context.MODE_PRIVATE));
 
     loadBackendApiClient();
     loadInstallationIdAndAuthToken();
@@ -201,7 +202,8 @@ public void fetch_firstFetch_includesInstallationAuthToken() throws Exception {
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
             /* firstOpenTime= */ any(),
-            /* currentTime= */ any());
+            /* currentTime= */ any(),
+            /* customSignals= */ any());
   }
 
   @Test
@@ -400,7 +402,8 @@ public void fetch_gettingFetchCacheFails_doesNotThrowException() throws Exceptio
 
   @Test
   public void fetch_fetchBackendCallFails_taskThrowsException() throws Exception {
-    when(mockBackendFetchApiClient.fetch(any(), any(), any(), any(), any(), any(), any(), any()))
+    when(mockBackendFetchApiClient.fetch(
+            any(), any(), any(), any(), any(), any(), any(), any(), any()))
         .thenThrow(
             new FirebaseRemoteConfigClientException("Fetch failed due to an unexpected error."));
 
@@ -549,7 +552,7 @@ public void fetch_getsMultipleFailedResponsesFromServer_resetsBackoffAfterSucces
 
     assertWithMessage("Fetch() failed!").that(fetchTask.isSuccessful()).isTrue();
 
-    BackoffMetadata backoffMetadata = metadataClient.getBackoffMetadata();
+    BackoffMetadata backoffMetadata = sharedPrefsClient.getBackoffMetadata();
     assertThat(backoffMetadata.getNumFailedFetches()).isEqualTo(NO_FAILED_FETCHES);
     assertThat(backoffMetadata.getBackoffEndTime()).isEqualTo(NO_BACKOFF_TIME);
   }
@@ -706,8 +709,9 @@ public void fetch_firstAndOnlyFetchFails_metadataFailStatusAndNoFetchYetTime() t
 
     fetchHandler.fetch();
 
-    assertThat(metadataClient.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_FAILURE);
-    assertThat(metadataClient.getLastSuccessfulFetchTime()).isEqualTo(LAST_FETCH_TIME_NO_FETCH_YET);
+    assertThat(sharedPrefsClient.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_FAILURE);
+    assertThat(sharedPrefsClient.getLastSuccessfulFetchTime())
+        .isEqualTo(LAST_FETCH_TIME_NO_FETCH_YET);
   }
 
   @Test
@@ -716,8 +720,8 @@ public void fetch_fetchSucceeds_metadataSuccessStatusAndFetchTimeUpdated() throw
 
     fetchHandler.fetch();
 
-    assertThat(metadataClient.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_SUCCESS);
-    assertThat(metadataClient.getLastSuccessfulFetchTime())
+    assertThat(sharedPrefsClient.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_SUCCESS);
+    assertThat(sharedPrefsClient.getLastSuccessfulFetchTime())
         .isEqualTo(firstFetchedContainer.getFetchTime());
   }
 
@@ -731,8 +735,8 @@ public void fetch_firstFetchSucceedsSecondFetchFails_failStatusAndFirstFetchTime
 
     fetchHandler.fetch(/* minimumFetchIntervalInSeconds= */ 0);
 
-    assertThat(metadataClient.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_FAILURE);
-    assertThat(metadataClient.getLastSuccessfulFetchTime())
+    assertThat(sharedPrefsClient.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_FAILURE);
+    assertThat(sharedPrefsClient.getLastSuccessfulFetchTime())
         .isEqualTo(firstFetchedContainer.getFetchTime());
   }
 
@@ -745,8 +749,8 @@ public void getInfo_twoFetchesSucceed_successStatusAndSecondFetchTime() throws E
 
     fetchHandler.fetch(/* minimumFetchIntervalInSeconds= */ 0);
 
-    assertThat(metadataClient.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_SUCCESS);
-    assertThat(metadataClient.getLastSuccessfulFetchTime())
+    assertThat(sharedPrefsClient.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_SUCCESS);
+    assertThat(sharedPrefsClient.getLastSuccessfulFetchTime())
         .isEqualTo(secondFetchedContainer.getFetchTime());
   }
 
@@ -759,11 +763,35 @@ public void getInfo_hitsThrottleLimit_throttledStatus() throws Exception {
 
     fetchHandler.fetch(/* minimumFetchIntervalInSeconds= */ 0);
 
-    assertThat(metadataClient.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_THROTTLED);
-    assertThat(metadataClient.getLastSuccessfulFetchTime())
+    assertThat(sharedPrefsClient.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_THROTTLED);
+    assertThat(sharedPrefsClient.getLastSuccessfulFetchTime())
         .isEqualTo(firstFetchedContainer.getFetchTime());
   }
 
+  @Test
+  public void fetch_usesLatestCustomSignals() throws Exception {
+    Map<String, String> customSignals =
+        ImmutableMap.of(
+            "subscription", "premium",
+            "age", "20");
+    sharedPrefsClient.setCustomSignals(customSignals);
+    fetchCallToHttpClientUpdatesClockAndReturnsConfig(firstFetchedContainer);
+    fetchHandler.fetch();
+
+    verify(mockBackendFetchApiClient)
+        .fetch(
+            any(HttpURLConnection.class),
+            /* instanceId= */ any(),
+            /* instanceIdToken= */ any(),
+            /* analyticsUserProperties= */ any(),
+            /* lastFetchETag= */ any(),
+            /* customHeaders= */ any(),
+            /* firstOpenTime= */ any(),
+            /* currentTime= */ any(),
+            /* customSignals= */ eq(sharedPrefsClient.getCustomSignals()));
+    assertThat(sharedPrefsClient.getCustomSignals()).isEqualTo(customSignals);
+  }
+
   private ConfigFetchHandler getNewFetchHandler(AnalyticsConnector analyticsConnector) {
     ConfigFetchHandler fetchHandler =
         spy(
@@ -775,7 +803,7 @@ private ConfigFetchHandler getNewFetchHandler(AnalyticsConnector analyticsConnec
                 mockRandom,
                 mockFetchedCache,
                 mockBackendFetchApiClient,
-                metadataClient,
+                sharedPrefsClient,
                 /* customHttpHeaders= */ ImmutableMap.of()));
     return fetchHandler;
   }
@@ -809,7 +837,8 @@ private void setBackendResponseConfigsTo(ConfigContainer container) throws Excep
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
             /* firstOpenTime= */ any(),
-            /* currentTime= */ any());
+            /* currentTime= */ any(),
+            /* customSignals= */ any());
   }
 
   private void setBackendResponseToNoChange(Date date) throws Exception {
@@ -821,7 +850,8 @@ private void setBackendResponseToNoChange(Date date) throws Exception {
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
             /* firstOpenTime= */ any(),
-            /* currentTime= */ any()))
+            /* currentTime= */ any(),
+            /* customSignals= */ any()))
         .thenReturn(FetchResponse.forBackendHasNoUpdates(date, firstFetchedContainer));
   }
 
@@ -836,7 +866,8 @@ private void fetchCallToBackendThrowsException(int httpErrorCode) throws Excepti
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
             /* firstOpenTime= */ any(),
-            /* currentTime= */ any());
+            /* currentTime= */ any(),
+            /* customSignals= */ any());
   }
 
   /**
@@ -875,7 +906,8 @@ private void callFetchAssertThrottledAndAdvanceClock(int httpCode) throws Except
 
     long backoffDurationInMillis =
         loadAndGetNextBackoffDuration(
-            /* numFailedFetches= */ metadataClient.getBackoffMetadata().getNumFailedFetches() + 1);
+            /* numFailedFetches= */ sharedPrefsClient.getBackoffMetadata().getNumFailedFetches()
+                + 1);
 
     assertThrowsThrottledException(fetchHandler.fetch(/* minimumFetchIntervalInSeconds= */ 0L));
 
@@ -900,7 +932,7 @@ private long loadAndGetNextBackoffDuration(int numFailedFetches) {
   }
 
   private void setMinimumFetchIntervalInMetadata(long minimumFetchIntervalInSeconds) {
-    metadataClient.setConfigSettings(
+    sharedPrefsClient.setConfigSettings(
         new FirebaseRemoteConfigSettings.Builder()
             .setMinimumFetchIntervalInSeconds(minimumFetchIntervalInSeconds)
             .build());
@@ -916,7 +948,8 @@ private void verifyBackendIsCalled() throws Exception {
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
             /* firstOpenTime= */ any(),
-            /* currentTime= */ any());
+            /* currentTime= */ any(),
+            /* customSignals= */ any());
   }
 
   private void verifyBackendIsCalled(Map<String, String> userProperties, Long firstOpenTime)
@@ -930,7 +963,8 @@ private void verifyBackendIsCalled(Map<String, String> userProperties, Long firs
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
             /* firstOpenTime= */ eq(firstOpenTime),
-            /* currentTime= */ any());
+            /* currentTime= */ any(),
+            /* customSignals= */ any());
   }
 
   private void verifyBackendIsNeverCalled() throws Exception {
@@ -943,7 +977,8 @@ private void verifyBackendIsNeverCalled() throws Exception {
             /* lastFetchETag= */ any(),
             /* customHeaders= */ any(),
             /* firstOpenTime= */ any(),
-            /* currentTime= */ any());
+            /* currentTime= */ any(),
+            /* customSignals= */ any());
   }
 
   private void verifyETags(@Nullable String requestETag, String responseETag) throws Exception {
@@ -956,8 +991,9 @@ private void verifyETags(@Nullable String requestETag, String responseETag) thro
             /* lastFetchETag= */ eq(requestETag),
             /* customHeaders= */ any(),
             /* firstOpenTime= */ any(),
-            /* currentTime= */ any());
-    assertThat(metadataClient.getLastFetchETag()).isEqualTo(responseETag);
+            /* currentTime= */ any(),
+            /* customSignals= */ any());
+    assertThat(sharedPrefsClient.getLastFetchETag()).isEqualTo(responseETag);
   }
 
   private void loadBackendApiClient() throws Exception {
@@ -966,7 +1002,7 @@ private void loadBackendApiClient() throws Exception {
   }
 
   private void loadETags(String requestETag, String responseETag) {
-    metadataClient.setLastFetchETag(requestETag);
+    sharedPrefsClient.setLastFetchETag(requestETag);
     this.responseETag = responseETag;
   }
 
@@ -981,7 +1017,7 @@ private void loadCacheAndClockWithConfig(
     when(cacheClient.getBlocking()).thenReturn(container);
     when(cacheClient.get()).thenReturn(Tasks.forResult(container));
     mockClock.setCurrentTime(container.getFetchTime().getTime());
-    metadataClient.updateLastFetchAsSuccessfulAt(container.getFetchTime());
+    sharedPrefsClient.updateLastFetchAsSuccessfulAt(container.getFetchTime());
   }
 
   private static void cachePutReturnsConfig(
diff --git a/firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigFetchHttpClientTest.java b/firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigFetchHttpClientTest.java
index edbded6f79b..ae068b4f8d2 100644
--- a/firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigFetchHttpClientTest.java
+++ b/firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigFetchHttpClientTest.java
@@ -344,7 +344,8 @@ private FetchResponse fetch(String eTag) throws Exception {
         eTag,
         /* customHeaders= */ ImmutableMap.of(),
         /* firstOpenTime= */ null,
-        /* currentTime= */ new Date(mockClock.currentTimeMillis()));
+        /* currentTime= */ new Date(mockClock.currentTimeMillis()),
+        /* customSignals= */ ImmutableMap.of());
   }
 
   private FetchResponse fetch(String eTag, Map<String, String> userProperties, Long firstOpenTime)
@@ -357,7 +358,8 @@ private FetchResponse fetch(String eTag, Map<String, String> userProperties, Lon
         eTag,
         /* customHeaders= */ ImmutableMap.of(),
         firstOpenTime,
-        new Date(mockClock.currentTimeMillis()));
+        new Date(mockClock.currentTimeMillis()),
+        /* customSignals= */ ImmutableMap.of());
   }
 
   private FetchResponse fetch(String eTag, Map<String, String> customHeaders) throws Exception {
@@ -369,7 +371,8 @@ private FetchResponse fetch(String eTag, Map<String, String> customHeaders) thro
         eTag,
         customHeaders,
         /* firstOpenTime= */ null,
-        new Date(mockClock.currentTimeMillis()));
+        new Date(mockClock.currentTimeMillis()),
+        /* customSignals= */ ImmutableMap.of());
   }
 
   private FetchResponse fetchWithoutInstallationId() throws Exception {
@@ -381,7 +384,8 @@ private FetchResponse fetchWithoutInstallationId() throws Exception {
         /* lastFetchETag= */ "bogus-etag",
         /* customHeaders= */ ImmutableMap.of(),
         /* firstOpenTime= */ null,
-        new Date(mockClock.currentTimeMillis()));
+        new Date(mockClock.currentTimeMillis()),
+        /* customSignals= */ ImmutableMap.of());
   }
 
   private FetchResponse fetchWithoutInstallationAuthToken() throws Exception {
@@ -393,7 +397,8 @@ private FetchResponse fetchWithoutInstallationAuthToken() throws Exception {
         /* lastFetchETag= */ "bogus-etag",
         /* customHeaders= */ ImmutableMap.of(),
         /* firstOpenTime= */ null,
-        new Date(mockClock.currentTimeMillis()));
+        new Date(mockClock.currentTimeMillis()),
+        /* customSignals= */ ImmutableMap.of());
   }
 
   private void setServerResponseTo(JSONObject requestBody, String eTag) {
diff --git a/firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigMetadataClientTest.java b/firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigSharedPrefsClientTest.java
similarity index 60%
rename from firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigMetadataClientTest.java
rename to firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigSharedPrefsClientTest.java
index e2c38df4a30..2edfb171ddc 100644
--- a/firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigMetadataClientTest.java
+++ b/firebase-config/src/test/java/com/google/firebase/remoteconfig/internal/ConfigSharedPrefsClientTest.java
@@ -21,20 +21,24 @@
 import static com.google.firebase.remoteconfig.FirebaseRemoteConfig.LAST_FETCH_STATUS_THROTTLED;
 import static com.google.firebase.remoteconfig.RemoteConfigComponent.CONNECTION_TIMEOUT_IN_SECONDS;
 import static com.google.firebase.remoteconfig.internal.ConfigFetchHandler.DEFAULT_MINIMUM_FETCH_INTERVAL_IN_SECONDS;
-import static com.google.firebase.remoteconfig.internal.ConfigMetadataClient.LAST_FETCH_TIME_IN_MILLIS_NO_FETCH_YET;
-import static com.google.firebase.remoteconfig.internal.ConfigMetadataClient.LAST_FETCH_TIME_NO_FETCH_YET;
-import static com.google.firebase.remoteconfig.internal.ConfigMetadataClient.NO_BACKOFF_TIME;
-import static com.google.firebase.remoteconfig.internal.ConfigMetadataClient.NO_FAILED_FETCHES;
+import static com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.LAST_FETCH_TIME_IN_MILLIS_NO_FETCH_YET;
+import static com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.LAST_FETCH_TIME_NO_FETCH_YET;
+import static com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.NO_BACKOFF_TIME;
+import static com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.NO_FAILED_FETCHES;
 
 import android.content.Context;
 import android.content.SharedPreferences;
 import androidx.test.core.app.ApplicationProvider;
 import com.google.common.base.Preconditions;
+import com.google.common.collect.ImmutableMap;
 import com.google.firebase.remoteconfig.FirebaseRemoteConfigInfo;
 import com.google.firebase.remoteconfig.FirebaseRemoteConfigSettings;
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient.BackoffMetadata;
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient.LastFetchStatus;
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.BackoffMetadata;
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient.LastFetchStatus;
+import java.util.Collections;
 import java.util.Date;
+import java.util.HashMap;
+import java.util.Map;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
@@ -42,121 +46,123 @@
 import org.robolectric.annotation.Config;
 
 /**
- * Unit tests for the {@link ConfigMetadataClient}.
+ * Unit tests for the {@link ConfigSharedPrefsClient}.
  *
  * @author Miraziz Yusupov
  */
 @RunWith(RobolectricTestRunner.class)
 @Config(manifest = Config.NONE)
-public class ConfigMetadataClientTest {
-  private ConfigMetadataClient metadataClient;
+public class ConfigSharedPrefsClientTest {
+  private ConfigSharedPrefsClient sharedPrefsClient;
   private FirebaseRemoteConfigSettings.Builder settingsBuilder;
 
   @Before
   public void setUp() {
-    SharedPreferences metadata =
+    SharedPreferences sharedPrefs =
         ApplicationProvider.getApplicationContext()
             .getSharedPreferences("TEST_FILE_NAME", Context.MODE_PRIVATE);
 
-    metadata.edit().clear().commit();
+    sharedPrefs.edit().clear().commit();
 
-    metadataClient = new ConfigMetadataClient(metadata);
+    sharedPrefsClient = new ConfigSharedPrefsClient(sharedPrefs);
 
     settingsBuilder = new FirebaseRemoteConfigSettings.Builder();
   }
 
   @Test
   public void getFetchTimeoutInSeconds_isNotSet_returnsDefault() {
-    assertThat(metadataClient.getFetchTimeoutInSeconds()).isEqualTo(CONNECTION_TIMEOUT_IN_SECONDS);
+    assertThat(sharedPrefsClient.getFetchTimeoutInSeconds())
+        .isEqualTo(CONNECTION_TIMEOUT_IN_SECONDS);
   }
 
   @Test
   public void getFetchTimeoutInSeconds_isSetTo10Seconds_returns10Seconds() {
     long expectedFetchTimeout = 10L;
-    metadataClient.setConfigSettings(
+    sharedPrefsClient.setConfigSettings(
         settingsBuilder.setFetchTimeoutInSeconds(expectedFetchTimeout).build());
 
-    long fetchTimeout = metadataClient.getFetchTimeoutInSeconds();
+    long fetchTimeout = sharedPrefsClient.getFetchTimeoutInSeconds();
 
     assertThat(fetchTimeout).isEqualTo(expectedFetchTimeout);
   }
 
   @Test
   public void getMinimumFetchIntervalInSeconds_isNotSet_returnsDefault() {
-    assertThat(metadataClient.getMinimumFetchIntervalInSeconds())
+    assertThat(sharedPrefsClient.getMinimumFetchIntervalInSeconds())
         .isEqualTo(DEFAULT_MINIMUM_FETCH_INTERVAL_IN_SECONDS);
   }
 
   @Test
   public void getMinimumFetchIntervalInSeconds_isSetTo10Seconds_returns10Seconds() {
     long expectedMinimumFetchInterval = 10L;
-    metadataClient.setConfigSettings(
+    sharedPrefsClient.setConfigSettings(
         settingsBuilder.setMinimumFetchIntervalInSeconds(expectedMinimumFetchInterval).build());
 
-    long minimumFetchInterval = metadataClient.getMinimumFetchIntervalInSeconds();
+    long minimumFetchInterval = sharedPrefsClient.getMinimumFetchIntervalInSeconds();
 
     assertThat(minimumFetchInterval).isEqualTo(expectedMinimumFetchInterval);
   }
 
   @Test
   public void getLastFetchStatus_isNotSet_returnsZero() {
-    assertThat(metadataClient.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_NO_FETCH_YET);
+    assertThat(sharedPrefsClient.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_NO_FETCH_YET);
   }
 
   @Test
   public void getLastFetchStatus_isSetToSuccess_returnsSuccess() {
-    metadataClient.updateLastFetchAsSuccessfulAt(new Date(100L));
+    sharedPrefsClient.updateLastFetchAsSuccessfulAt(new Date(100L));
 
-    @LastFetchStatus int lastFetchStatus = metadataClient.getLastFetchStatus();
+    @LastFetchStatus int lastFetchStatus = sharedPrefsClient.getLastFetchStatus();
 
     assertThat(lastFetchStatus).isEqualTo(LAST_FETCH_STATUS_SUCCESS);
   }
 
   @Test
   public void getLastSuccessfulFetchTime_isNotSet_returnsZero() {
-    assertThat(metadataClient.getLastSuccessfulFetchTime()).isEqualTo(LAST_FETCH_TIME_NO_FETCH_YET);
+    assertThat(sharedPrefsClient.getLastSuccessfulFetchTime())
+        .isEqualTo(LAST_FETCH_TIME_NO_FETCH_YET);
   }
 
   @Test
   public void getLastSuccessfulFetchTime_isSet_returnsTime() {
     Date fetchTime = new Date(1000L);
-    metadataClient.updateLastFetchAsSuccessfulAt(fetchTime);
+    sharedPrefsClient.updateLastFetchAsSuccessfulAt(fetchTime);
 
-    Date lastSuccessfulFetchTime = metadataClient.getLastSuccessfulFetchTime();
+    Date lastSuccessfulFetchTime = sharedPrefsClient.getLastSuccessfulFetchTime();
 
     assertThat(lastSuccessfulFetchTime).isEqualTo(fetchTime);
   }
 
   @Test
   public void getLastFetchETag_isNotSet_returnsEmptyString() {
-    assertThat(metadataClient.getLastFetchETag()).isNull();
+    assertThat(sharedPrefsClient.getLastFetchETag()).isNull();
   }
 
   @Test
   public void getLastFetchETag_isSet_returnsETag() {
     String expectedETag = "an etag";
-    metadataClient.setLastFetchETag(expectedETag);
+    sharedPrefsClient.setLastFetchETag(expectedETag);
 
-    String eTag = metadataClient.getLastFetchETag();
+    String eTag = sharedPrefsClient.getLastFetchETag();
 
     assertThat(eTag).isEqualTo(expectedETag);
   }
 
   @Test
   public void getLastTemplateVersion_isNotSet_returnsDefault() {
-    assertThat(metadataClient.getLastTemplateVersion()).isEqualTo(0);
+    assertThat(sharedPrefsClient.getLastTemplateVersion()).isEqualTo(0);
   }
 
   @Test
   public void getLastTemplateVersion_isSet_returnsTemplateVersion() {
-    metadataClient.setLastTemplateVersion(1);
-    assertThat(metadataClient.getLastTemplateVersion()).isEqualTo(1);
+    sharedPrefsClient.setLastTemplateVersion(1);
+    assertThat(sharedPrefsClient.getLastTemplateVersion()).isEqualTo(1);
   }
 
   @Test
   public void getRealtimeBackoffMetadata_isNotSet_returnsNoFailedStreamsAndNotThrottled() {
-    ConfigMetadataClient.RealtimeBackoffMetadata defaultRealtimeBackoffMetadata =
-        metadataClient.getRealtimeBackoffMetadata();
+    ConfigSharedPrefsClient.RealtimeBackoffMetadata defaultRealtimeBackoffMetadata =
+        sharedPrefsClient.getRealtimeBackoffMetadata();
 
     assertThat(defaultRealtimeBackoffMetadata.getNumFailedStreams()).isEqualTo(NO_FAILED_FETCHES);
     assertThat(defaultRealtimeBackoffMetadata.getBackoffEndTime()).isEqualTo(NO_BACKOFF_TIME);
@@ -166,10 +172,10 @@ public void getRealtimeBackoffMetadata_isNotSet_returnsNoFailedStreamsAndNotThro
   public void getRealtimeBackoffMetadata_hasValues_returnsValues() {
     int numFailedStreams = 5;
     Date backoffEndTime = new Date(1000L);
-    metadataClient.setRealtimeBackoffMetadata(numFailedStreams, backoffEndTime);
+    sharedPrefsClient.setRealtimeBackoffMetadata(numFailedStreams, backoffEndTime);
 
-    ConfigMetadataClient.RealtimeBackoffMetadata backoffMetadata =
-        metadataClient.getRealtimeBackoffMetadata();
+    ConfigSharedPrefsClient.RealtimeBackoffMetadata backoffMetadata =
+        sharedPrefsClient.getRealtimeBackoffMetadata();
 
     assertThat(backoffMetadata.getNumFailedStreams()).isEqualTo(numFailedStreams);
     assertThat(backoffMetadata.getBackoffEndTime()).isEqualTo(backoffEndTime);
@@ -177,26 +183,26 @@ public void getRealtimeBackoffMetadata_hasValues_returnsValues() {
 
   @Test
   public void resetRealtimeBackoff_hasValues_clearsAllValues() {
-    metadataClient.setRealtimeBackoffMetadata(
+    sharedPrefsClient.setRealtimeBackoffMetadata(
         /* numFailedStreams= */ 5, /* backoffEndTime= */ new Date(1000L));
 
-    ConfigMetadataClient.RealtimeBackoffMetadata realtimeBackoffMetadata =
-        metadataClient.getRealtimeBackoffMetadata();
+    ConfigSharedPrefsClient.RealtimeBackoffMetadata realtimeBackoffMetadata =
+        sharedPrefsClient.getRealtimeBackoffMetadata();
     Preconditions.checkArgument(realtimeBackoffMetadata.getNumFailedStreams() != NO_FAILED_FETCHES);
     Preconditions.checkArgument(
         !realtimeBackoffMetadata.getBackoffEndTime().equals(NO_BACKOFF_TIME));
 
-    metadataClient.resetRealtimeBackoff();
+    sharedPrefsClient.resetRealtimeBackoff();
 
-    ConfigMetadataClient.RealtimeBackoffMetadata resetMetadata =
-        metadataClient.getRealtimeBackoffMetadata();
+    ConfigSharedPrefsClient.RealtimeBackoffMetadata resetMetadata =
+        sharedPrefsClient.getRealtimeBackoffMetadata();
     assertThat(resetMetadata.getNumFailedStreams()).isEqualTo(NO_FAILED_FETCHES);
     assertThat(resetMetadata.getBackoffEndTime()).isEqualTo(NO_BACKOFF_TIME);
   }
 
   @Test
   public void getBackoffMetadata_isNotSet_returnsNoFailedFetchesAndNotThrottled() {
-    BackoffMetadata defaultBackoffMetadata = metadataClient.getBackoffMetadata();
+    BackoffMetadata defaultBackoffMetadata = sharedPrefsClient.getBackoffMetadata();
 
     assertThat(defaultBackoffMetadata.getNumFailedFetches()).isEqualTo(NO_FAILED_FETCHES);
     assertThat(defaultBackoffMetadata.getBackoffEndTime()).isEqualTo(NO_BACKOFF_TIME);
@@ -206,9 +212,9 @@ public void getBackoffMetadata_isNotSet_returnsNoFailedFetchesAndNotThrottled()
   public void getBackoffMetadata_hasValues_returnsValues() {
     int numFailedFetches = 5;
     Date backoffEndTime = new Date(1000L);
-    metadataClient.setBackoffMetadata(numFailedFetches, backoffEndTime);
+    sharedPrefsClient.setBackoffMetadata(numFailedFetches, backoffEndTime);
 
-    BackoffMetadata backoffMetadata = metadataClient.getBackoffMetadata();
+    BackoffMetadata backoffMetadata = sharedPrefsClient.getBackoffMetadata();
 
     assertThat(backoffMetadata.getNumFailedFetches()).isEqualTo(numFailedFetches);
     assertThat(backoffMetadata.getBackoffEndTime()).isEqualTo(backoffEndTime);
@@ -216,23 +222,23 @@ public void getBackoffMetadata_hasValues_returnsValues() {
 
   @Test
   public void resetBackoff_hasValues_clearsAllValues() {
-    metadataClient.setBackoffMetadata(
+    sharedPrefsClient.setBackoffMetadata(
         /* numFailedFetches= */ 5, /* backoffEndTime= */ new Date(1000L));
 
-    BackoffMetadata backoffMetadata = metadataClient.getBackoffMetadata();
+    BackoffMetadata backoffMetadata = sharedPrefsClient.getBackoffMetadata();
     Preconditions.checkArgument(backoffMetadata.getNumFailedFetches() != NO_FAILED_FETCHES);
     Preconditions.checkArgument(!backoffMetadata.getBackoffEndTime().equals(NO_BACKOFF_TIME));
 
-    metadataClient.resetBackoff();
+    sharedPrefsClient.resetBackoff();
 
-    BackoffMetadata resetMetadata = metadataClient.getBackoffMetadata();
+    BackoffMetadata resetMetadata = sharedPrefsClient.getBackoffMetadata();
     assertThat(resetMetadata.getNumFailedFetches()).isEqualTo(NO_FAILED_FETCHES);
     assertThat(resetMetadata.getBackoffEndTime()).isEqualTo(NO_BACKOFF_TIME);
   }
 
   @Test
   public void getInfo_hasNoSetValues_returnsDefaults() {
-    FirebaseRemoteConfigInfo info = metadataClient.getInfo();
+    FirebaseRemoteConfigInfo info = sharedPrefsClient.getInfo();
 
     assertThat(info.getFetchTimeMillis()).isEqualTo(LAST_FETCH_TIME_IN_MILLIS_NO_FETCH_YET);
     assertThat(info.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_NO_FETCH_YET);
@@ -245,18 +251,18 @@ public void getInfo_hasNoSetValues_returnsDefaults() {
   @Test
   public void getInfo_hasSetValues_returnsValues() {
     Date lastSuccessfulFetchTime = new Date(1000L);
-    metadataClient.updateLastFetchAsSuccessfulAt(lastSuccessfulFetchTime);
-    metadataClient.updateLastFetchAsFailed();
+    sharedPrefsClient.updateLastFetchAsSuccessfulAt(lastSuccessfulFetchTime);
+    sharedPrefsClient.updateLastFetchAsFailed();
 
     long fetchTimeout = 666L;
     long minimumFetchInterval = 666L;
-    metadataClient.setConfigSettings(
+    sharedPrefsClient.setConfigSettings(
         new FirebaseRemoteConfigSettings.Builder()
             .setFetchTimeoutInSeconds(fetchTimeout)
             .setMinimumFetchIntervalInSeconds(minimumFetchInterval)
             .build());
 
-    FirebaseRemoteConfigInfo info = metadataClient.getInfo();
+    FirebaseRemoteConfigInfo info = sharedPrefsClient.getInfo();
 
     assertThat(info.getFetchTimeMillis()).isEqualTo(lastSuccessfulFetchTime.getTime());
     assertThat(info.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_FAILURE);
@@ -267,9 +273,9 @@ public void getInfo_hasSetValues_returnsValues() {
 
   @Test
   public void getInfo_firstAndOnlyFetchFails_failStatusAndNoFetchYetTime() {
-    metadataClient.updateLastFetchAsFailed();
+    sharedPrefsClient.updateLastFetchAsFailed();
 
-    FirebaseRemoteConfigInfo info = metadataClient.getInfo();
+    FirebaseRemoteConfigInfo info = sharedPrefsClient.getInfo();
 
     assertThat(info.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_FAILURE);
     assertThat(info.getFetchTimeMillis()).isEqualTo(LAST_FETCH_TIME_IN_MILLIS_NO_FETCH_YET);
@@ -278,9 +284,9 @@ public void getInfo_firstAndOnlyFetchFails_failStatusAndNoFetchYetTime() {
   @Test
   public void getInfo_fetchSucceeds_successStatusAndFetchTimeUpdated() {
     Date fetchTime = new Date(100L);
-    metadataClient.updateLastFetchAsSuccessfulAt(fetchTime);
+    sharedPrefsClient.updateLastFetchAsSuccessfulAt(fetchTime);
 
-    FirebaseRemoteConfigInfo info = metadataClient.getInfo();
+    FirebaseRemoteConfigInfo info = sharedPrefsClient.getInfo();
 
     assertThat(info.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_SUCCESS);
     assertThat(info.getFetchTimeMillis()).isEqualTo(fetchTime.getTime());
@@ -289,11 +295,11 @@ public void getInfo_fetchSucceeds_successStatusAndFetchTimeUpdated() {
   @Test
   public void getInfo_firstFetchSucceedsSecondFetchFails_failStatusAndFirstFetchTime() {
     Date fetchTime = new Date(100L);
-    metadataClient.updateLastFetchAsSuccessfulAt(fetchTime);
+    sharedPrefsClient.updateLastFetchAsSuccessfulAt(fetchTime);
 
-    metadataClient.updateLastFetchAsFailed();
+    sharedPrefsClient.updateLastFetchAsFailed();
 
-    FirebaseRemoteConfigInfo info = metadataClient.getInfo();
+    FirebaseRemoteConfigInfo info = sharedPrefsClient.getInfo();
 
     assertThat(info.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_FAILURE);
     assertThat(info.getFetchTimeMillis()).isEqualTo(fetchTime.getTime());
@@ -302,12 +308,12 @@ public void getInfo_firstFetchSucceedsSecondFetchFails_failStatusAndFirstFetchTi
   @Test
   public void getInfo_twoFetchesSucceed_successStatusAndSecondFetchTime() {
     Date fetchTime = new Date(100L);
-    metadataClient.updateLastFetchAsSuccessfulAt(fetchTime);
+    sharedPrefsClient.updateLastFetchAsSuccessfulAt(fetchTime);
 
     Date secondFetchTime = new Date(200L);
-    metadataClient.updateLastFetchAsSuccessfulAt(secondFetchTime);
+    sharedPrefsClient.updateLastFetchAsSuccessfulAt(secondFetchTime);
 
-    FirebaseRemoteConfigInfo info = metadataClient.getInfo();
+    FirebaseRemoteConfigInfo info = sharedPrefsClient.getInfo();
 
     assertThat(info.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_SUCCESS);
     assertThat(info.getFetchTimeMillis()).isEqualTo(secondFetchTime.getTime());
@@ -316,11 +322,11 @@ public void getInfo_twoFetchesSucceed_successStatusAndSecondFetchTime() {
   @Test
   public void getInfo_hitsThrottleLimit_throttledStatus() {
     Date fetchTime = new Date(100L);
-    metadataClient.updateLastFetchAsSuccessfulAt(fetchTime);
+    sharedPrefsClient.updateLastFetchAsSuccessfulAt(fetchTime);
 
-    metadataClient.updateLastFetchAsThrottled();
+    sharedPrefsClient.updateLastFetchAsThrottled();
 
-    FirebaseRemoteConfigInfo info = metadataClient.getInfo();
+    FirebaseRemoteConfigInfo info = sharedPrefsClient.getInfo();
 
     assertThat(info.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_THROTTLED);
     assertThat(info.getFetchTimeMillis()).isEqualTo(fetchTime.getTime());
@@ -329,19 +335,19 @@ public void getInfo_hitsThrottleLimit_throttledStatus() {
   @Test
   public void clear_hasSetValues_clearsAll() {
     Date lastSuccessfulFetchTime = new Date(1000L);
-    metadataClient.updateLastFetchAsSuccessfulAt(lastSuccessfulFetchTime);
+    sharedPrefsClient.updateLastFetchAsSuccessfulAt(lastSuccessfulFetchTime);
 
     long fetchTimeout = 666L;
     long minimumFetchInterval = 666L;
-    metadataClient.setConfigSettings(
+    sharedPrefsClient.setConfigSettings(
         new FirebaseRemoteConfigSettings.Builder()
             .setFetchTimeoutInSeconds(fetchTimeout)
             .setMinimumFetchIntervalInSeconds(minimumFetchInterval)
             .build());
 
-    metadataClient.clear();
+    sharedPrefsClient.clear();
 
-    FirebaseRemoteConfigInfo info = metadataClient.getInfo();
+    FirebaseRemoteConfigInfo info = sharedPrefsClient.getInfo();
     assertThat(info.getFetchTimeMillis()).isEqualTo(LAST_FETCH_TIME_IN_MILLIS_NO_FETCH_YET);
     assertThat(info.getLastFetchStatus()).isEqualTo(LAST_FETCH_STATUS_NO_FETCH_YET);
     assertThat(info.getConfigSettings().getFetchTimeoutInSeconds())
@@ -349,4 +355,40 @@ public void clear_hasSetValues_clearsAll() {
     assertThat(info.getConfigSettings().getMinimumFetchIntervalInSeconds())
         .isEqualTo(DEFAULT_MINIMUM_FETCH_INTERVAL_IN_SECONDS);
   }
+
+  @Test
+  public void getCustomSignals_isNotSet_returnsEmptyMap() {
+    assertThat(sharedPrefsClient.getCustomSignals()).isEqualTo(Collections.emptyMap());
+  }
+
+  @Test
+  public void getCustomSignals_isSet_returnsCustomSignals() {
+    Map<String, String> SAMPLE_CUSTOM_SIGNALS =
+        ImmutableMap.of(
+            "subscription", "premium",
+            "age", "20");
+    sharedPrefsClient.setCustomSignals(SAMPLE_CUSTOM_SIGNALS);
+    assertThat(sharedPrefsClient.getCustomSignals()).isEqualTo(SAMPLE_CUSTOM_SIGNALS);
+  }
+
+  @Test
+  public void setCustomSignals_multipleTimes_addsNewSignals() {
+    Map<String, String> signals1 = ImmutableMap.of("subscription", "premium");
+    Map<String, String> signals2 = ImmutableMap.of("age", "20", "subscription", "basic");
+    sharedPrefsClient.setCustomSignals(signals1);
+    sharedPrefsClient.setCustomSignals(signals2);
+    Map<String, String> expectedSignals = ImmutableMap.of("subscription", "basic", "age", "20");
+    assertThat(sharedPrefsClient.getCustomSignals()).isEqualTo(expectedSignals);
+  }
+
+  @Test
+  public void setCustomSignals_nullValue_removesSignal() {
+    Map<String, String> signals1 = ImmutableMap.of("subscription", "premium", "age", "20");
+    sharedPrefsClient.setCustomSignals(signals1);
+    Map<String, String> signals2 = new HashMap<>();
+    signals2.put("age", null);
+    sharedPrefsClient.setCustomSignals(signals2);
+    Map<String, Object> expectedSignals = ImmutableMap.of("subscription", "premium");
+    assertThat(sharedPrefsClient.getCustomSignals()).isEqualTo(expectedSignals);
+  }
 }
diff --git a/firebase-config/src/test/java/com/google/firebase/remoteconfig/ktx/RemoteConfigTests.kt b/firebase-config/src/test/java/com/google/firebase/remoteconfig/ktx/RemoteConfigTests.kt
index c11ea869fbf..2a423843a7c 100644
--- a/firebase-config/src/test/java/com/google/firebase/remoteconfig/ktx/RemoteConfigTests.kt
+++ b/firebase-config/src/test/java/com/google/firebase/remoteconfig/ktx/RemoteConfigTests.kt
@@ -32,8 +32,8 @@ import com.google.firebase.remoteconfig.createRemoteConfig
 import com.google.firebase.remoteconfig.internal.ConfigCacheClient
 import com.google.firebase.remoteconfig.internal.ConfigFetchHandler
 import com.google.firebase.remoteconfig.internal.ConfigGetParameterHandler
-import com.google.firebase.remoteconfig.internal.ConfigMetadataClient
 import com.google.firebase.remoteconfig.internal.ConfigRealtimeHandler
+import com.google.firebase.remoteconfig.internal.ConfigSharedPrefsClient
 import com.google.firebase.remoteconfig.internal.rollouts.RolloutsStateSubscriptionsHandler
 import org.junit.After
 import org.junit.Before
@@ -142,7 +142,7 @@ class ConfigTests : BaseTestCase() {
         defaultConfigsCache = mock(ConfigCacheClient::class.java),
         fetchHandler = mock(ConfigFetchHandler::class.java),
         getHandler = mockGetHandler,
-        frcMetadata = mock(ConfigMetadataClient::class.java),
+        frcSharedPrefs = mock(ConfigSharedPrefsClient::class.java),
         realtimeHandler = mock(ConfigRealtimeHandler::class.java),
         rolloutsStateSubscriptionsHandler = mock(RolloutsStateSubscriptionsHandler::class.java)
       )