# Webhook > An HTTP request one system sends to another automatically when an event happens. Also known as: webhooks, customer webhooks. Category: Software. A webhook is an HTTP callback: when an event occurs in one system, it sends a request to a URL registered by another system. This makes integrations event-driven instead of repeatedly polling for changes. ## How PhotoRobot uses it PhotoRobot Cloud sends signed customer webhooks for events such as item.status.changed, item.status.bulk_changed and hosting.item.availability.changed. Payloads are deliberately small; the receiver verifies the X-PhotoRobot-Signature header and then pulls the current item from the REST v2 API. Subscriptions, test sends and a delivery log are managed in the PhotoRobot Account in Developers mode. ## See on photorobot.com - [Customer webhooks for PhotoRobot Cloud](https://www.photorobot.com/blog/customer-webhooks) ## Related terms - [PhotoRobot Cloud API](https://www.photorobot.com/glossary/cloud-api): PhotoRobot's REST API for integrating the studio with catalogue, DAM, PIM and e-commerce systems. - [API (application programming interface)](https://www.photorobot.com/glossary/api): A defined interface through which one piece of software can use the functions or data of another. - [DAM (digital asset management)](https://www.photorobot.com/glossary/dam): Software for storing, organising, searching and distributing images, video and other media files. - [PIM (product information management)](https://www.photorobot.com/glossary/pim): A system that stores and distributes product data, such as descriptions and attributes, to all sales channels. - [Item status](https://www.photorobot.com/glossary/item-status): The production state of an item in PhotoRobot Controls, such as Received, Captured, Edited or Published. ## Where this term appears on photorobot.com Mentioned on 3 pages. Most relevant: - [Introducing: Customer Webhooks for PhotoRobot Cloud](https://www.photorobot.com/blog/customer-webhooks): PhotoRobot introduces Customer Webhooks for PhotoRobot Cloud to connect your DAM, PIM, ERP, or custom automation with signed outbound webhooks. - [A Smarter PhotoRobot Account - Rebuilt for Admins](https://www.photorobot.com/blog/smarter-photorobot-account): Needs attention – subscription blocked or pending payment, missing invoice email, unpaid orders, support replies waiting, failed webhooks, and pending invitations — with direct CTAs Overview – storage… - [PhotoRobot Architecture & Data Flow](https://www.photorobot.com/security/architecture): OCR: Google Vision API APIs: REST API for customer systems Webhooks: Optional for event notifications Data Flow (Conceptual).