Build an AI Chatbot App with React Native, Expo, and Google’s Bard API

In this tutorial, we’ll guide you through developing an AI chatbot application using React Native, Expo, and Google’s Bard API. You’ll learn how to create a dynamic user interface, navigate between screens, and integrate AI-powered responses into your app. An accompanying video walks through the full process.

This guide provides a comprehensive walkthrough of building an AI chatbot application. We’ll cover using React Native and Expo to create a visually appealing and functional user interface. You’ll learn how to implement screen navigation using React Navigation. The core of the app involves integrating Google’s Bard API for AI-powered responses, enhancing user interaction and providing helpful information within the chatbot.

Technology Stack

Let’s explore the technologies we will be utilizing to construct this AI chatbot application:

• React Native: A framework for building native mobile apps with JavaScript.
• Expo: A toolchain built around React Native to help you build, deploy, and quickly iterate on iOS, Android, and web apps from the same JavaScript/TypeScript codebase.
• React Navigation: Provides a simple way to navigate between screens in your app.
• Google’s Bard API: A large language model from Google AI.
• Next.js: A React framework for building server-rendered and statically generated web applications. We’ll use it to create the API endpoint for communicating with the Bard API.

Setting Up Your Development Environment

Before we begin coding, let’s set up our development environment. Make sure you have Node.js and npm (Node Package Manager) installed on your system.

Installing Expo CLI

Expo CLI (Command Line Interface) is a tool for creating and managing Expo projects. To install it, open your terminal and run the following command:

npm install -g expo-cli

Creating a New React Native Project with Expo

Now that you have Expo CLI installed, let’s create a new React Native project. In your terminal, navigate to the directory where you want to create your project and run the following command:

npx create-expo-app ai-chatbot-app

Replace "ai-chatbot-app" with your desired project name. Expo CLI will prompt you to choose a template. Select the "blank" template for a minimal starting point.

Navigating to Your Project Directory

Once the project is created, navigate to the project directory:

cd ai-chatbot-app

Building the User Interface

Let’s start building the user interface for our AI chatbot application. We’ll create a landing page with different avatar options and a chat screen where users can interact with the AI.

Creating the Landing Page

The landing page will display a selection of chatbot avatars for the user to choose from. Each avatar will have a distinct color scheme that affects the app’s overall appearance. Use React Native components like View, Text, Image, and TouchableOpacity to structure and style the landing page.

For example, you can create a FlatList to display the different avatar options. When an avatar is selected, store the selected avatar’s data in the component’s state.

Implementing Screen Navigation with React Navigation

To navigate between the landing page and the chat screen, we’ll use React Navigation. First, install the necessary packages:

npm install @react-navigation/native @react-navigation/stack

Also, install the required peer dependencies:

npx expo install react-native-gesture-handler react-native-reanimated react-native-screens react-native-safe-area-context @react-native-community/masked-view

Create a navigation container in your App.js file and define the screens using a Stack.Navigator. For example:

javascript import { NavigationContainer } from ‘@react-navigation/native’; import { createStackNavigator } from ‘@react-navigation/stack’;

const Stack = createStackNavigator();

function App() { return (

); }

Use the navigation.navigate() function to navigate between screens when an avatar is selected on the landing page. Pass the selected avatar’s data as a parameter to the chat screen.

Designing the Chat Screen

The chat screen will display the conversation between the user and the AI. It will also include an input field for the user to type their messages and a button to send them.

Use React Native components like ScrollView, View, Text, TextInput, and TouchableOpacity to structure and style the chat screen. Display the messages in a list, with different styles for user messages and AI responses.

Implement a loading animation to indicate that the AI is processing the user’s message.

Integrating with Google’s Bard API

To integrate with Google’s Bard API, we need to create a backend API endpoint using Next.js. This endpoint will receive the user’s message, send it to the Bard API, and return the AI’s response.

Setting Up a Next.js API Endpoint

Create a new Next.js project or use an existing one. In the pages/api directory, create a new file (e.g., bard.js) to define the API endpoint.

Install the necessary dependencies:

bash npm install @google-cloud/aiplatform

Implement the API endpoint to handle the request and communicate with the Bard API. You’ll need to authenticate with Google Cloud and use the Vertex AI SDK to interact with the Bard model.

javascript import { VertexAI } from ‘@google-cloud/aiplatform’;

const PROJECT_ID = ‘your-project-id’; const LOCATION = ‘us-central1’; const MODEL_NAME = ‘gemini-1.0-pro’;

export default async function handler(req, res) { if (req.method === ‘POST’) { const { message } = req.body;

const vertexAI = new VertexAI({ project: PROJECT_ID, location: LOCATION });
const model = vertexAI.getGenerativeModel({
  model: MODEL_NAME,
  generation_config: {
    maxOutputTokens: 2048,
    temperature: 0.9,
    topP: 1,
  },
  safety_settings: [
    {
      category: 'HARM_CATEGORY_HARASSMENT',
      threshold: 'BLOCK_MEDIUM_AND_ABOVE',
    },
    {
      category: 'HARM_CATEGORY_HATE_SPEECH',
      threshold: 'BLOCK_MEDIUM_AND_ABOVE',
    },
    {
      category: 'HARM_CATEGORY_SEXUALLY_EXPLICIT',
      threshold: 'BLOCK_MEDIUM_AND_ABOVE',
    },
    {
      category: 'HARM_CATEGORY_DANGEROUS_CONTENT',
      threshold: 'BLOCK_MEDIUM_AND_ABOVE',
    },
  ],
});

const request = {
  contents: [{ role: 'user', parts: [{ text: message }] }],
};

try {
  const response = await model.generateContent(request);
  const text = response.responses[0].candidates[0].content.parts[0].text;
  res.status(200).json({ response: text });
} catch (error) {
  console.error(error);
  res.status(500).json({ error: 'Failed to generate content' });
}

} else { res.status(405).json({ error: ‘Method Not Allowed’ }); } }

Calling the API Endpoint from React Native

In your React Native chat screen, use the fetch API to call the Next.js API endpoint when the user sends a message. Send the user’s message in the request body and handle the response from the API.

Update the chat screen’s state with the AI’s response to display it in the conversation.

Enhancements and Further Development

This is a basic implementation of an AI chatbot application. You can enhance it further by adding features like:

• User authentication and profiles.
• Real-time chat with other users.
• Multimedia support (images, videos, etc.).
• Customizable chatbot personalities.
• Integration with other AI services.

Key Takeaways

• React Native and Expo provide a powerful platform for building cross-platform mobile applications.
• React Navigation simplifies screen navigation in React Native apps.
• Google’s Bard API enables you to integrate AI-powered responses into your applications.
• Next.js is useful to write your Rest API.
• Building a full-stack AI chatbot application involves combining front-end and back-end technologies.

Frequently Asked Questions (FAQs)

What is Expo?

Expo is a framework and a platform for universal React applications. It is a set of tools and services built around React Native to help you develop, build, deploy, and quickly iterate on iOS, Android, and web apps from the same JavaScript/TypeScript codebase.

Is Google’s Bard API free to use?

Google may offer a free tier for Bard API with certain usage limits, or it might be entirely usage-based. Refer to the official Bard API documentation for the most up-to-date pricing information.

Can I deploy the Next.js API endpoint to other platforms besides Vercel?

Yes, you can deploy your Next.js API endpoint to various platforms like Netlify, AWS, Google Cloud, or any other platform that supports Node.js serverless functions or container deployments.

By following this tutorial, you’ve learned how to build an AI chatbot application using React Native, Expo, and Google’s Bard API. This project demonstrates the power of combining mobile development with AI to create engaging and intelligent user experiences. You can further customize and enhance this application to meet your specific needs and explore the vast possibilities of AI in mobile development.

Credit: Creator

Credit: Writer

Credit: Reviewer