I'm excited to announce Dropbox webhooks, a way for server-side apps to get real-time notifications about file changes in Dropbox. Client-side applications have already been able to get low-latency notifications via longpoll_delta or the built-in notifications in the Sync API . Webhooks give this same ability to server-side apps, eliminating the need for polling.

What's a webhook?

In general, a webhook is a way for an app developer to specify a URI to receive notifications based on some trigger. In the case of Dropbox, notifications get sent to your webhook URI every time a user of your app makes a file change. The payload of the webhook is a list of user IDs who have changes. Your app can then use the standard delta method to see what changed and respond accordingly.

What can you do with webhooks?

Webhooks are great for any app that needs to respond quickly to changes in Dropbox. In the webhooks tutorial, we show an example app that converts Markdown files to HTML as soon as they're added to Dropbox. We released webhooks to a few companies in private beta to better understand how the feature would be used in real apps. Here's how two of those companies are using webhooks today:

Picturelife stores all your photos and videos securely in the cloud, giving you access to them wherever you are. Here's what Nate Westheimer, CEO of Picturelife, had to say about webhooks: "The new webhooks API is perfect for apps like Picturelife. Our backend sync services now get to work smarter, not harder. Rather than constantly making thousands of requests, polling for changes, we get to sit back and wait for users to make changes, and then only make the requests we need. Meanwhile, this new API turns out to be a real win for our customers too. With webhooks, our users now have the best, most up-to-date experience, right when they login to Picturelife."