What is a WebHook & how to Configure webhhooks

A webhook is a method for an app to provide other applications with real-time information. It works by delivering data to other applications as it happens, meaning you get data immediately. Unlike typical APIs where you need to poll for data very frequently in order to get it real-time, webhooks are automated calls from a source application to a third-party appliction

To use a webhook, follow these steps:

1. Set up the Webhook on the Server: The server where you want to receive the data must have a webhook URL – an endpoint set up to accept data. This involves writing a small service that listens for requests at a specific URL.

2. Configure the Source Application: In the application that will send data, configure the webhook by specifying the URL of the server where data should be sent. You might also set what events should trigger the webhook.

3. Test the Webhook: Send a test event from the source application to ensure the data is received correctly by the server.

4. Handle Incoming Data: On the server, write code to process incoming webhook data. This could involve parsing the data, performing some action with it, or storing it in a database.

5. Securing Webhooks: Implement security measures like validating the source of the data, using HTTPS, and possibly using a secret or a token to verify the data's authenticity.

6. Monitoring and Error Handling: Since webhooks rely on real-time data transfer, it’s important to monitor for failed deliveries and have a plan for handling missed or duplicated data.

Webhooks are commonly used in various applications like automating tasks, integrating with third-party services, and building event-driven architectures. For instance, a webhook can notify your application when a new user signs up, or when a transaction occurs in a payment system.

Example

Receiving Telegram Notifications for New Gmail Emails

Objective: Set up a system where you get a Telegram notification every time a new email arrives in your Gmail inbox.

Prerequisites:

• A Gmail account

• A Telegram bot (created via BotFather in Telegram)

• A server to host your webhook

Steps:

1. Google API and Gmail Setup:

• Enable the Gmail API in Google Developer Console for your project.

• Authenticate using OAuth 2.0 to access your Gmail account.

1. Telegram Bot Setup:

• Create a Telegram bot using BotFather.

• Note down the bot token provided by BotFather.

1. Webhook Server Setup:

• Set up a server with an endpoint to handle incoming webhook requests.

• This server will listen for notifications from Gmail and send messages to Telegram.

1. Google Cloud Pub/Sub Configuration:

• Create a Pub/Sub topic in Google Cloud.

• Subscribe to this topic with your server's webhook URL.

1. Gmail Watch Request:

• Send a 'watch' request from your server to Gmail, linking to the Pub/Sub topic.

• This instructs Gmail to publish notifications to the topic on new emails.

1. Handling Notifications and Sending Telegram Messages:

• When a new email notification is received, your server parses it.

• Using the Telegram bot API, send a message to your Telegram account about the new email.

1. Security and Maintenance:

• Secure the webhook endpoint and regularly monitor and update the system as needed.

Outcome: Every time a new email hits your Gmail inbox, your server gets notified and sends you a Telegram message via your bot, keeping you informed in real-time.