Building a React Native Chat App with CometChat UI Kit

Building chat apps in React Native from scratch is an ambitious task that comes with a range of complex challenges, such as:

CometChat's React Native UI Kit simplifies this process by offering pre-built, customizable chat components that eliminate the heavy lifting, while still allowing developers the flexibility to align the chat experience with their unique app requirements.

To better understand how CometChat can accelerate your development process, here's a quick comparison of building a chat app using the traditional DIY approach versus leveraging CometChat:

In this tutorial, we'll build a full-featured chat application that supports:

By the end of this tutorial, you'll have a production-ready chat application that can be easily customized to match your brand and requirements, all powered by CometChat's robust backend infrastructure.

Prerequisites

Before starting, ensure you have:

• Node.js (version 14 or higher)

• React Native CLI (version 0.70.0 or higher)

• JDK 11

• npm or yarn package manager

• Android Studio (for Android development)

• Xcode 13+ (for iOS development)

• iOS 12.0 or later (for iOS development)

• CometChat account (free plan available)

Getting started

Step 1: Create a New React Native Project

Start by creating a fresh React Native project using the CLI. The command will set up a new React Native project with the latest stable version.

Step 2. Install Required Dependencies

Install the following packages with their specific versions to ensure compatibility:

For React Native 0.76 and above, also install:

iOS Setup

Step 3: Configure Project Settings

For optimal compatibility, disable the new React Native architecture for both platforms:

For iOS, update your ios/Podfile:

For Android, update android/gradle.properties:

Step 4: Add Platform Permissions

Add the necessary permissions,

• For Android: Update AndroidManifest.xml with storage, vibration, and internet permissions

• For iOS: Update Info.plist with required permissions

Android Permissions

Add the following permissions to android/app/src/main/AndroidManifest.xml inside the <manifest> tag:

Note: For Android development, ensure ANDROID_HOME environment variable is properly set or configure sdk.dir in local.properties

iOS Permissions

Add the following keys to ios/YourAppName/Info.plist inside the <dict> tag:

Note: Customize the permission description strings to match your app's specific use cases and privacy policy.

Step 5: Initialize CometChat

Create a configuration file to handle CometChat initialization. This setup includes:

• Permission handling for Android

• CometChat UI Kit initialization

• Error handling and initialization status

• Environment-specific configuration

Create a new file src/config/cometChat.js

Important security note: The Auth Key should only be used during development. For production, use Auth Tokens for secure user authentication.

Building the chat app interface

1. User login and authentication flow

Before diving into building the chat interface, we'll create a login component that authenticates users with CometChat using their unique User ID. This authentication system is fundamental as it establishes a secure connection between users and CometChat servers, managing user sessions and ensuring proper access to conversations.

We'll create a login form that:

Step 1: Create a new authentication context to manage login state

Create src/context/AuthContext.js:

Step 2: Create Error Boundary Component

Create src/components/ErrorBoundary.js

Step 3: Create a Login screen

Create src/screens/LoginScreen.js:

2. Building the chat interface

Update App.js:

Adding advanced functionalities on top of the existing features

1. Setting up notifications 

Now that your chat functionality is up and running, it's time to enable notifications so users never miss a message. CometChat’s Notifications module allows you to set up and manage notifications across multiple providers directly from the dashboard, ensuring centralized control and effortless configuration. You can easily integrate push notifications with APNs and FCM, email notifications with SendGrid, and SMS alerts with Twilio, or use webhooks to connect with any provider of your choice.

You can also enable notification preferences for your users, allowing them to customize when and how they receive notifications. Additionally, our customizable templates let you tailor notifications to your app’s tone and branding.

2. Setting up advanced moderation

Next, we’ll explore CometChat’s powerful moderation capabilities, which you can enable using the CometChat SDK. These features are designed to help maintain a safe, respectful environment for users and allow you to moderate content in real time.

Front-end moderation

Moderation queue:

Use our centralized moderation dashboard to give app admins an organized view of flagged messages, reported users, and blocked content. From this dashboard, admins can take real-time action on flagged content, issue user bans or warnings, and escalate issues for higher-level review, all in one place.

Proactive content moderation:

Use our advanced AI filters to prevent harmful content from entering your chat. These filters automatically screen every message exchanged in your app for violations defined by you and take action based on the moderation rules you’ve set up with our rules engine.

CometChat’s rules engine lets you create custom rules to address common moderation scenarios. You can define which filters to use for identifying violations and specify how to handle them, such as blocking a user or removing them from a group. This helps you keep your app free from:

3. Using Webhooks to extend your chat app's functionality

Leverage webhooks to trigger actions based on key events like message exchanges, user interactions, group changes, and call activities. You can use them to automate tasks, integrate with external services, and optimize the chat experience in your app. You can configure these webhooks directly from the CometChat dashboard.

Here’s a list of available webhooks:

Customizing Your Chat Interface

One of the key advantages of using CometChat's UI Kit is the ability to easily customize the appearance and behavior of your chat interface. In this section, we'll explore how to customize your chat app at both the theme level and component level.

Theme Level Customization

CometChat's theme system allows you to make app-wide changes to colors, typography, and other visual elements. The theme consists of two main components:

1. Palette: Controls the app's color scheme

The palette defines colors for various elements, with built-in support for light and dark modes to ensure seamless theme switching. Key color categories include:

Each color category can be configured with separate values for light and dark modes.

2. Typography: Defines text styles and appearances

Typography allows you to customize the text across your app for different use cases. The key text styles include:

All these customizations can be applied through the theme configuration, ensuring consistent styling across your entire chat application.

Setting Up Custom Theme

Create a new file src/config/theme.js to manage your theme customizations:

Applying the custom theme

Update your App.js to initialize and apply the custom theme:

Component customization 

Conversations component customisation

The Conversations component displays all conversations related to the currently logged-in user. To ensure the component aligns with your app's design and branding, you can easily customize its appearance by adjusting the properties exposed by the ConversationsStyle class. Below, you'll find a table outlining all the properties you can modify to tailor the component to your specific needs.

For more advanced customization, you can define custom views within the Conversations component. This allows you to fully control and tailor each element of the interface, such as layouts, views, and UI elements, ensuring that the component perfectly matches your app's overall aesthetics and functionality. .

Messages component customization 

The Messages component is a central feature of our chat interface, responsible for rendering the area where messages are exchanged between users and groups. It plays a key role in managing the real-time flow of messages within the app. Below, you'll find a table outlining all the properties you can modify to tailor the messages component to your specific needs

Testing Your Chat App

Before you deploy your project to production, it's important to properly structure, test, and verify that everything works as expected. In this section, we'll walk you through how to run the project locally, test key features, and ensure that everything is functioning properly before moving to deployment.

Your final project structure should look like this

Testing checklist

1. Configuration Check

Verify CometChat credentials in cometChat.js

Ensure all required permissions are in place for both platforms

2. Functional Testing

Test the following flows to ensure your chat app is working correctly:

Authentication Flow

• Try logging in with valid test user credentials

• Verify error handling with invalid credentials

• Check if login session persists after app restart

Chat Functionality

Login with two different test users on different devices

• Start a conversation between these users

• Verify real-time message delivery

• Test media sharing capabilities

• Check user online/offline status updates

UI/Theme Verification

• Verify your custom theme is applied correctly

• Test on both iOS and Android devices

• Check all interactive elements (buttons, inputs)

Deployment Preparation

Android Release

Step 1: Generate Release Keystore

Step 2: Configure Gradle Properties

Create or update android/gradle.properties

Step 3: Update build.gradle

Edit android/app/build.gradle :

Step 4: Create Final Release Build

The release APK will be in android/app/build/outputs/apk/release/

iOS Release

Xcode Configuration

• Open Xcode

• Select your project

• Set Build Configuration to Release

• Update version and build numbers

• Configure signing certificates

Archive and Upload

• Select Generic iOS Device as the build target

• Choose Product > Archive

• In Archives window, click "Distribute App"

• Follow App Store distribution workflow

Final Deployment Checklist

• Verify production CometChat credentials

• Remove any test API keys

• Configure proper error reporting

Haris Kumar

Lead Content Strategist , CometChat

Haris brings nearly half a decade of expertise in B2B SaaS content marketing, where he excels at developing strategic content that drives engagement and supports business growth. His deep understanding of the SaaS landscape allows him to craft compelling narratives that resonate with target audiences. Outside of his professional pursuits, Haris enjoys reading, trying out new dishes and watching new movies!