# The TLDR on Alchemy Custom Webhooks

The goal of custom webhooks is to allow developers to ingest our proprietary alert data into any 3rd-party tool they want as well as in any format they want.

# Table of Contents
1. [What are webhooks?](#1.-what-are-webhooks?)
2. [Does Alchemy support webhooks?](#example2)
3. [What are custom webhooks?](#third-example)
4. [Does Alchemy support custom webhooks?](#fourth-examplehttpwwwfourthexamplecom)

## 1. What are webhooks?

Webhooks, also referred to as "reverse API"s, is a way for one web application to notify another web application when an event has occurred. In web2 systems, an example of a live webhook could be one that sends an alert every time a new user registers. In web3,

Webhooks, also referred to as "reverse APIs", enable developers to facilitate real-time communication between two applications in an automated manner. As opposed to continuously *polling* servers for information, webhooks are quick, easy-to-set up, and are often perceived as a lightweight alternative to building out a full-fledged API service.


As you can see in the image above, webhooks allows you to receive data on a **subscription** basis (ie, As soon as `x` happens, tell me about it.) rather than via **polling** (ie, Did `x` happen? If yes, can you tell me about it?).

As opposed to continuously polling an endpoint to determine whether a state change has occurred, webhooks provide information as soon as it becomes available. In other words, webhooks can be regarded as “reverse APIs” because communication is initiated by the program supplying the data rather than the one requesting it.

## 2. Does Alchemy have webhooks?

You bet! Using the [Alchemy Notify API](https://www.alchemy.com/notify), developers can push real-time notifications to users for critical events such as **address activity**, **mined transactions**, and other use cases. Here are a few listed out:

1. [Address Activity Notifications](https://docs.alchemy.com/reference/address-activity-webhook): This provides your app with real-time state changes when an address sends/receives tokens or ETH.
2. [Mined Transaction Notifications](https://docs.alchemy.com/reference/mined-transaction-webhook): Notifies your app when a transaction sent through your app gets mined.
3. [NFT Activity Notifications](https://docs.alchemy.com/reference/address-activity-webhook): This provides your app with real-time state changes when an NFT is transferred between addresses.

Alchemy's webhooks allow web3 dApps to instantly and automatically relay data from the blockchain.

## 3. How to set up an Alchemy webhook?

[VIDEO?]

## 4. What are custom webhooks?

Just like webhooks but you can customize them to process your data in whatever format you want!

## 5. Does Alchemy support custom webhooks?

YOU BET. Here's an activity to jumpstart your custom webhooks journey.

# PostgresSQL

PostgreSQL Databases let you store, read and write persistent data quickly. Great for storing user or application data that changes over time.