What is a webhook used for?

Webhooks are a way to send and receive data between two services only when a change has happened. This is extremely useful because it cuts down on having to create or manage an always-on connection between two services. This decreases time spent on development, data used, and potential for transfer errors.

Understanding webhooks

Webhooks are HTTP-based callback functions that facilitate event-driven communication between two application programming interfaces (APIs). While traditional APIs require the client to periodically poll the server for updates, webhooks take a different approach. In a webhook setup, the client provides a unique URL to the server API and specifies the event it wants to be notified about. 

Read also: What is HTTP? 

Understanding APIs

APIs, or application programming interfaces, are protocols and definitions used for building and integrating application software. They define the structure of requests and responses when communicating between different applications.

API communication typically follows a client-server model, where the client app sends HTTP requests to the server app to request data or perform actions. The server app then responds with the requested data or an acknowledgment of the action taken. This process is known as polling, where the client repeatedly sends requests until the server provides the required information.

Read also: The 5-minute guide to Paubox Email API 

The difference with webhooks

Webhooks, often referred to as reverse or push APIs, shift the responsibility of communication from the client to the server. Instead of the client polling for updates, the server proactively sends a single HTTP post request to the client's webhook URL when the specified event occurs. This approach eliminates the need for continuous polling and allows for real-time, event-driven communication.

One aspect to note is that webhooks are not standalone APIs; they work in conjunction with existing APIs. An application must have an API in place to use webhooks effectively. Webhooks act as a mechanism to hook into specific events on the server side and prompt the server to send the relevant payload to the client via the web.

Benefits of webhooks

Webhooks offer several advantages over traditional polling-based communication:

Elimination of polling

Using webhooks, the client application no longer needs to continuously poll the server for updates. This saves resources and reduces unnecessary network traffic.

Quick and easy setup

Setting up webhooks is relatively straightforward. If an application supports webhooks, they can be configured through the server's user interface. The client simply enters their webhook URL and specifies the desired event, making it easy to get started.

Automation of data transfer

Webhooks enable automation by automatically sending the payload as soon as the specified event occurs on the server. This allows for real-time data transfer and eliminates the need for manual intervention.

Lightweight and specific payloads

Webhooks are designed for handling small amounts of data between two endpoints. The server determines the size and timing of the data transfer, while the client interprets and uses the payload accordingly. This makes webhooks ideal for sending notifications or specific updates.

Paubox’s webhook features 

• Paubox’s webhook functionality provides a near-instantaneous payload to the service of your choice on the delivery status of any message sent via the Paubox API
• Delivery statuses include “Delivered”, “Temporary Failure” (soft bounce), and “Permanent Failure” (hard bounce)
• The payload from a webhook also provides data about the email including subject, to, from, date sent, and the message ID
• The data provided from a webhook should be considered PII per HIPAA guidelines
• Paubox can send data to any endpoint that can receive a POST request but note that the payload is not customizable (an example payload can be found here)

See also: HIPAA compliant email API

FAQs

What is a webhook used for?

Webhooks are typically used to connect two different applications. When an event happens on the trigger application, it serializes data about that event and sends it to a webhook URL from the action application.

What is the difference between API and webhook?

A webhook will primarily upload or download data for a given trigger, but not necessarily both. Meanwhile, an API is designed specifically to maintain communication.

Is webhook a server?

Webhook is a lightweight, configurable tool that allows you to easily create HTTP endpoints (hooks) on your server, which you can use to execute configured commands.