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## Resource: About Backend Events

## Article: About Backend Events

## Article Link: https://dev.wix.com/docs/studio-two/code-your-site/build-a-custom-backend/backend-events/about-backend-events.md

## Article Content:

# About Backend Events

A [Backend Events](https://dev.wix.com/docs/overview/extensions-framework/backend-extensions/event-extensions.md) extension is custom backend logic that Wix runs when a platform event fires, such as when a contact is created. In Studio Two you add one from the **Code** tab through the **Wix Extension Builder**, and the extension is part of the site project.

Wix Studio and Wix Editor sites don't use this extension. They handle events with Velo backend event handlers instead.

## How backend events work in Studio Two

- You add the extension from the **Code** tab. The Builder puts its files in your site project and registers them.
- The generated handler listens for the Contact Created event. To listen for a different event, change the import and the handler method. The events and their payloads are in the [API reference](https://dev.wix.com/docs/api-reference?apiView=SDK.md).
- Wix calls the handler when the event occurs. The handler runs without a visitor or member identity, so use elevation to call Wix APIs that need permissions. For more, see [Event Extensions](https://dev.wix.com/docs/overview/extensions-framework/backend-extensions/event-extensions.md).
- A handler doesn't write a log entry on its own. To record that it ran, call the monitoring client from the handler. `console` output doesn't appear in your site's logs. See [Write Log Messages in Studio Two](https://dev.wix.com/docs/studio-two/test-your-site/work-with-logs/write-log-messages.md).

## See also

- [Add a Backend Events Extension in Studio Two](https://dev.wix.com/docs/studio-two/code-your-site/build-a-custom-backend/backend-events/add-a-backend-events-extension-in-studio-two.md)
- [Build a Backend Events Extension in Studio Two](https://dev.wix.com/docs/studio-two/code-your-site/build-a-custom-backend/backend-events/build-a-backend-events-extension-in-studio-two.md)
- [Event Extension Files and Code](https://dev.wix.com/docs/backend-extensions/backend-events/event-extension-files-and-code.md)
- [About Studio Two Extensions](https://dev.wix.com/docs/studio-two/get-started/about-studio-two-extensions.md)