Firebase Remote Config Basics

Remote Config

This skill provides a complete guide for getting started with Remote Config on Android or iOS. Remote Config allows you to change the behavior and appearance of your app without publishing an app update by maintaining a cloud-based configuration template.

Prerequisites

Provisioning Remote Config requires both a Firebase project and a Firebase app, either Android or iOS. To manage the Remote Config template and conditions via the command line, use the Firebase CLI. See the firebase-basics skill for references on project initialization.

Troubleshooting Execution

Handling npx 403 Forbidden Errors

If npx -y firebase-tools@latest fails due to registry permissions (403 error):

1. Inform the user: "I am unable to fetch the latest Firebase tools via npx due to a registry error." 1. Fallback: Attempt to use the local firebase command directly if the user confirms it is installed globally (npm install -g firebase-tools).

Handling Project Context Issues

If a command fails because "no active project is selected":

1. Check login: Run npx -y firebase-tools@latest login:list. 1. Prompt for ID: If logged in but no project is active, ask the user: "Please provide your Firebase Project ID to proceed." 1. Use Flag: Append --project <PROJECT_ID> to every subsequent command.

SDK Setup

To learn how to set up Remote Config in your application code, choose your platform:

• Android: android_setup.md
• iOS: ios_setup.md

Best Practices and Template Management

Follow these guidelines and use the associated CLI tools to ensure efficient and safe use of Remote Config.

Fetching Strategies

To optimize app performance and user experience, follow these recommended patterns (see Loading Strategies):

• Load new values for next startup: The most effective pattern is to

activate previously fetched values immediately on startup and fetch new values in the background to be used next time. This minimizes user wait time.

• Real-time Updates: Use the SDK's real-time listener to update the app

instantly without a refresh when server-side configuration changes.

Template Management via CLI

Use the following commands to manage your Remote Config template and version history through the terminal:

Template Management via CLI

Use the following commands to manage your Remote Config template and version history through the terminal:

• Get current template: Save the remote template to a local JSON file for

auditing or modification.

  npx -y firebase-tools@latest remoteconfig:get -o remote_config.json

• Autonomous Editing & Discovery : Modify the local remote_config.json

directly. Determine the correct signal (e.g., device.country or percent) and update the "conditions" array and "parameters" map accordingly.

• MANDATORY: User Review and Verification : STOP and ask the user to verify

your changes before proceeding to deployment.

• Action: Inform the user: "I have prepared the changes in remote_config.json.

Please review the file for accuracy. Once you are satisfied, tell me to 'deploy' to make the changes live."

• Deployment Orchestration : To push changes, you must ensure the

environment is configured for deployment.

• Config Mapping: If a firebase.json file is missing, create one to map the

local JSON to the Remote Config service:

    { "remoteconfig": { "template": "remote_config.json" } }

• Deploy: Execute the partial deployment command

    npx -y firebase-tools@latest deploy --only remoteconfig

• Verification: After deployment, verify the update by listing the version

history.

  npx -y firebase-tools@latest remoteconfig:versions:list

The SDK provides a number of features to make your application dynamic and responsive to user segments.

• Set In-App Defaults: Define baseline values to ensure the app functions

offline or before the first fetch.

• Fetch and Activate: Retrieve values from the Firebase backend and apply

them to the local UI/Logic.

• Template Management: Use the Firebase CLI to version-control, get, and

deploy your config JSON files.

Firebase Remote Config Android Setup Guide

Important references:

• Refer to the firebase-basics skills, particularly those for project and app

setup, before proceeding.

Project and App Setup

Before you begin, ensure you have the following. If a google-services.json file is present, then use that Firebase project and app. Otherwise you may need to create them.

• Firebase CLI: Installed and logged in (see firebase-basics).
• Firebase Project: Created via

npx -y firebase-tools@latest projects:create (see firebase-basics).

• Firebase App: Created via

npx -y firebase-tools@latest apps:create <IOS|ANDROID|WEB> <package-name-or-bundle-id>

The google-services.json file must be present in the Android app's module directory. If missing, get the config using the Firebase CLI: npx -y firebase-tools@latest apps:sdkconfig ANDROID <App-ID>.

Add Dependencies to Gradle Build

These changes are made to your Android project's Gradle files. Google Analytics is highly recommended as it enables conditional targeting based on user properties and audiences.

Project-level build.gradle.kts (<project>/build.gradle.kts)

Ensure the Google Services plugin is in the plugins block:

plugins {
    // ... other plugins
    id("com.google.gms.google-services") version "4.4.0" apply false
}

App-level build.gradle.kts (<project>/<app-module>/build.gradle.kts)

1. Add the Google Services plugin to the plugins block:

   plugins {
       // ... other plugins
       id("com.google.gms.google-services")
   }

1. Add the Firebase Remote Config and Analytics dependencies. Using the Firebase Bill of Materials (BoM) is the best practice for version management.

   dependencies {
       // ... other dependencies

       // Import the Firebase BoM
       implementation(platform("com.google.firebase:firebase-bom:32.7.0"))

       // Add the dependencies for Remote Config and Analytics
       implementation("com.google.firebase:firebase-config-ktx")
       implementation("com.google.firebase:firebase-analytics-ktx")
   }

Follow up Steps

The following steps cover the essential patterns for using Remote Config effectively.

Set In-App Defaults

Define default values so your app has functional logic before it ever fetches a template from the server. Create an XML file (e.g., res/xml/remote_config_defaults.xml): xml <!-- Example Remote Config Defaults File --> <?xml version="1.0" encoding="utf-8"?> <defaultsMap> <entry> <key>welcome_message</key> <value>Welcome to the app!</value> </entry> <entry> <key>is_feature_enabled</key> <value>false</value> </entry> </defaultsMap> Then, initialize the SDK in your Activity or Application class:

````

val remoteConfig = Firebase.remoteConfig
remoteConfig.setDefaultsAsync(R.xml.remote_config_defaults)

````

Fetch and Activate Values

To apply values from the cloud, you must fetch them and then activate them. kotlin remoteConfig.fetchAndActivate() .addOnCompleteListener(this) { task -> if (task.isSuccessful) { val updated = task.result println("Config params updated: $updated") } else { println("Fetch failed") } // Access a value val message = remoteConfig.getString("welcome_message") }

Firebase Remote Config iOS Setup Guide

Important references:

• Refer to the firebase-basics skills, particularly those for iOS setup,

before proceeding.

• Refer to the xcode-project-setup skills.

Project and App Setup

Use the firebase-tools CLI to set up the project if necessary.

1. Find Bundle ID: Read the Xcode project to find the iOS bundle ID. Check the PRODUCT_BUNDLE_IDENTIFIER value in the .pbxproj file or the Info.plist file. 1. Create Firebase Project: If no project exists, create one: npx -y firebase-tools@latest projects:create <project-id> --display-name="My Awesome App" 1. Create Firebase App: Register the iOS app with the discovered bundle ID: npx -y firebase-tools@latest apps:create IOS <bundle-id> 1. Link the GoogleService-Info.plist file: Use the script in the xcode-project-setup skill to obtain the config and link.

Add Swift Package Dependencies

Install the Remote Config and Analytics SDKs using the Swift package manager.

Install the FirebaseRemoteConfig and FirebaseAnalytics packages from the https://github.com/firebase/firebase-ios-sdk.git repository.

Initialize Firebase in App Code

Modify the application's entry point to initialize Firebase. Refer to the iOS setup reference in the firebase-basics skill.

Follow up Steps

The following steps cover the essential patterns for using Remote Config effectively in your iOS app.

Set In-App Defaults

Define default values so your app behaves as intended before it connects to the backend. Create a property list file (e.g., RemoteConfigDefaults.plist):

````

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>welcome_message</key>
    <string>Welcome to the app!</string>
    <key>is_feature_enabled</key>
    <false/>
</dict>
</plist>

````

Then, initialize the SDK and set the defaults:

````

import FirebaseRemoteConfig

let remoteConfig = RemoteConfig.remoteConfig()
remoteConfig.setDefaults(fromPlist: "RemoteConfigDefaults")

````

Fetch and Activate Values

To retrieve values from the cloud and apply them to your app:

````

remoteConfig.fetchAndActivate { (status, error) in
    if status == .successFetchedFromRemote || status == .successUsingPreFetchedData {
        print("Config fetched and activated!")
    } else {
        print("Config not fetched")
    }
    
    // Access a value
    let message = remoteConfig.configValue(forKey: "welcome_message").stringValue
}

````