How to code your own WhatsApp chatbot?

WhatsApp has become one of the most popular messaging apps with over 2 billion active users worldwide. Given its huge user base, WhatsApp presents an excellent opportunity for businesses to automate customer service and build chatbots to engage with customers. Coding your own WhatsApp chatbot allows endless customization options to provide tailored experiences for your users. This comprehensive guide will walk you through step-by-step on how to code your own WhatsApp chatbot from scratch using Node.js.

What is a Chatbot?

A chatbot is an artificial intelligence (AI) program that simulates human conversation through text or voice interactions. Chatbots are used in applications such as customer service, website assistants, marketing campaigns and more.

Chatbots work by analyzing input from users, determining intent through natural language processing (NLP), and responding with appropriate messages or actions. Well-designed chatbots feel like talking to a real person by providing conversational responses based on programmed logic and machine learning algorithms.

Why Build a WhatsApp Chatbot?

Here are some key reasons to build a WhatsApp chatbot for your business:

Access a vast audience – WhatsApp has over 2 billion active users worldwide, providing a huge potential audience.
Enhance customer experience – Chatbots provide instant responses 24/7 and can handle common customer queries, improving CX.

Increase efficiency – Automating customer service can significantly reduce labor costs and free up staff time.
Get actionable insights – Chatbot conversations provide valuable data to analyze and optimize business processes.
Drive engagement – Chatbots allow personalized interactions that engage customers and build brand loyalty.

Integrate with workflows – Chatbots can connect with internal systems to integrate into business workflows like order status checks.

In summary, WhatsApp chatbots allow scalable and efficient customer communications to drive growth for businesses on a platform with massive reach.

What You Will Need

Here are the requirements and tools you will need to code your WhatsApp chatbot:

Node.js installed on your system – Download and install the latest version of Node.js which allows us to run JavaScript on the server.
WhatsApp Business API Account – Sign up for a WhatsApp business account to get API access and a business phone number.
WhatsApp Cloud API Access – Apply for WhatsApp Cloud API access which enables building chatbots.

Code Editor like VS Code – Download a code editor to write your chatbot code and scripts.
Local Tunneling Tool like ngrok – Used to tunnel traffic from WhatsApp servers to your local development system.

With these tools, you will have the necessary environment to start coding your WhatsApp chatbot.

Step 1 – Set up a WhatsApp Business Account

The first step is to set up a WhatsApp business account which provides access to the WhatsApp Business API. Here is how to set up a business account:

Download the WhatsApp app on your phone and verify your number.
Open WhatsApp, go to the settings menu and tap on “WhatsApp Web/Desktop”.

On the next screen, tap on “Add Account” followed by “Log in to WhatsApp Business”.
Enter your business details like name, email, address and hit next.
WhatsApp will verify your business information and if approved, provide a business account.

Take note of your new WhatsApp business number which you will need later.

Once your WhatsApp business account is approved and set up, you can move to the next step of applying for WhatsApp Business API access.

Step 2 – Apply for WhatsApp Business API Access

To start building your WhatsApp chatbot, you need access to the WhatsApp Business API. Here is how you can apply for API access:

Go to the WhatsApp Business API signup page – https://www.whatsapp.com/business/api
Enter your email address and hit the “Get Started” button.
Select the use case as “Build a Solution for your Business” and hit next.

Enter your business details like name, website, business description etc.
Read and accept the terms of service to submit your API access request.
WhatsApp will review your request and send API approval via email in 1-2 weeks.

Once approved, you will get access credentials like an API token which will be used during chatbot development.

Step 3 – Set up a Local Development Environment

To build and test your WhatsApp chatbot, you need to set up a local development environment on your computer. Follow these steps:

Install Node.js on your computer which allows running JavaScript code outside a web browser.

Download and install a code editor like Visual Studio Code to write your chatbot code.
Install ngrok tool which will tunnel traffic from WhatsApp to your local computer.
Make sure you have Git installed to import code libraries and packages.

You may also want to install Postman to test WhatsApp API requests.

Your local setup with Node.js, VS code, and ngrok provides the foundation to start coding and debugging your WhatsApp chatbot.

Step 4 – Import the Chatbot Code Library

Building a WhatsApp chatbot from scratch requires significant development effort. To simplify things, we will use the open-source library WhatsApp-Cloud-API provided by WhatsApp.

Follow these steps to import the code library into your project:

Clone the GitHub repository to your local machine: git clone https://github.com/whatsapp/WhatsApp-Cloud-API.git
Navigate into the repo directory: cd WhatsApp-Cloud-API

Install dependencies: npm install
Make a copy of .env.example as .env
Edit .env to add your WhatsApp Business API credentials and settings

This will setup the required code library containing pre-built components like a web server, middleware, controllers etc. to accelerate your WhatsApp chatbot development.

Step 5 – Develop the Chatbot Code

With the code scaffolding in place, we can now develop the chatbot logic by adding routes, handlers, and business logic. Here are the key steps:

Open controllers/webhooks.js which handles incoming webhooks from WhatsApp.

Add code in the incomingMessage() handler to analyze incoming messages and trigger appropriate responses.
Use conditional logic like if/else and entity detection to direct conversations.
Add custom handlers for capabilities like FAQ, notifications, conversations etc.

Implement a natural conversation flow based on your chatbot scope.
Integrate APIs or databases to connect your chatbot to external systems and data.

The WhatsApp-Cloud-API library provides many helpers and templates to accelerate building your custom chatbot code.

Step 6 – Tunnel Your Local Server

To test your chatbot, you need to make your local development server accessible to WhatsApp’s servers. This is done by tunneling your local host port using ngrok:

Run your Node.js server locally, for example: npm run dev
Open a new terminal window and run: ./ngrok http 3000 (replace 3000 with your server port)

ngrok will generate a public URL like https://abcdef123.ngrok.io
Update your WhatsApp webhook URL in the WhatsApp Business Manager with this ngrok URL.

Now traffic from WhatsApp will be tunneled to your local server through the ngrok URL allowing you to test your chatbot.

Step 7 – Connect a WhatsApp Number

To use your chatbot, you need to connect a WhatsApp number to it:

In WhatsApp business manager, go to Settings > Linked Devices
Click Add Device and enter the phone number of your WhatsApp business account

Open WhatsApp on your business account phone and tap “Link a Device”
Scan the QR code shown on business manager using your phone
Congratulations! Your business number is now linked to your chatbot.

You can now message your business number and start chatting with your custom WhatsApp chatbot.

Step 8 – Deploy the Chatbot

For running your chatbot in production, you need to deploy it on a server like AWS, GCP, Azure etc. Here are the steps:

Install Node.js runtime and required dependencies on the server
Copy your chatbot codebase to the server
Run and debug the code remotely to resolve any issues

Configure a domain name and SSL certificate for your server
Update your WhatsApp webhook with production server URL
Optionally use a process manager like PM2 for monitoring and clustering

Your chatbot is now deployed on a live production server instead of your local computer!

Conclusion

Building a WhatsApp chatbot provides immense value for businesses but requires expertise in Node.js, WhatsApp APIs and conversational interfaces. This guide provided a step-by-step process to code your own custom WhatsApp chatbot from scratch using the WhatsApp Business API.

Here are some key takeaways from this guide:

Set up a WhatsApp business account and get approved for WhatsApp Business API access
Use the WhatsApp-Cloud-API library to accelerate development
Develop custom handlers for natural conversation handling

Tunnel your local server using ngrok for testing
Link your business number to the chatbot to try it out
Deploy the chatbot on a cloud server for production use

By following these steps, you can build and deploy a fully-functional WhatsApp chatbot tailored to your specific business needs. The possibilities are endless once you master WhatsApp chatbot development using the powerful WhatsApp Business API.