# What is a webhook?

> A webhook pushes a notification the moment an event happens, so your systems react instantly. Learn how webhooks work and what to watch for in production.

A webhook is an automatic message one system sends to another the moment something happens, so the receiving system can react immediately instead of waiting to be asked.

Updated 6 Aug 2026

## What it does for your business.

A webhook is what makes things happen immediately rather than eventually. When a customer pays, when a WhatsApp message arrives, when a form is submitted, the system where it happened pushes a notification straight to your other system. Without one, your systems have to keep asking each other whether anything changed, which is slower, wasteful, and the reason data sometimes appears fifteen minutes late. In practice, it is the difference between a lead answered in seconds and one that waits for the next sync.

## How it actually works.

You give the sending system a web address that belongs to you. Whenever the chosen event occurs, that system delivers a small package of data to your address describing what happened: the order number, the customer, the amount. Your side receives it and runs whatever should follow. People sometimes call a webhook a reverse API, because instead of you asking for the data, the data is delivered to you the moment it exists.

## What to watch for.

Three practical things. Delivery is not guaranteed, so the receiver must cope with a notification arriving twice or out of order, which usually means checking whether the work has already been done. The address should be protected with a shared secret or signature, otherwise anyone who learns the URL can send you fake events. And failures need to be visible: a webhook that quietly stopped delivering last Tuesday should be reported by a monitor, not by a customer.

The Voltade take

Webhooks are how our agents hear about things in real time: a message on WhatsApp, a status change in a connected system, a document that just landed. We build the receiving side to expect duplicates and retries, because in production those are normal traffic, not edge cases.

Related pages

What is an API · What is an automation trigger · What is a WhatsApp webhook · Integrations

More from the glossary

AI Agent · PSG Grant · AI Agent vs Chatbot

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## Links

- [What is an API](https://voltade.com/sg/resources/glossary/what-is-an-api)
- [What is an automation trigger](https://voltade.com/sg/resources/glossary/what-is-an-automation-trigger)
- [What is a WhatsApp webhook](https://voltade.com/sg/resources/glossary/what-is-a-whatsapp-webhook)
- [Integrations](https://voltade.com/sg/integrations)
- [AI Agent](https://voltade.com/sg/resources/glossary/what-is-an-ai-agent)
- [PSG Grant](https://voltade.com/sg/resources/glossary/what-is-psg-grant)
- [AI Agent vs Chatbot](https://voltade.com/sg/resources/glossary/ai-agent-vs-chatbot)