> For the complete documentation index, see [llms.txt](https://developers.verida.network/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developers.verida.network/protocol/client-sdk/events.md).
# Events
Your application can listen to events for when data changes in your application.
## Data changes[β](https://developers.verida.network/docs/client-sdk/events#data-changes)
Once a `datastore` or `database` is opened, you can listen to changes to automatically update your application:
```typescript
const filter = {
status: 'active'
}
const listener = await database.changes(function(row) {
console.log("Row changed", row)
}, filter)
```
Try this out with your own profile data in the browser in our [tutorial](https://developers.verida.network/docs/tutorial/events).
Options:
* `filter`: An optional JSON object. The listener will only raise events if the data in the object matches the supplied filter.
You can cancel the event listener:
```typescript
listener.cancel()
```
Similarly you can call:
```typescript
const listener = await datastore.changes(function(row) { ... })
```
## Inbox messages[β](https://developers.verida.network/docs/client-sdk/events#inbox-messages)
You can be notified when a new inbox message arrives for your application:
```typescript
const messaging = await context.getMessaging()
messaging.onMessage(function(message) { console.log('New message!', message)})
```
## Database sync changes[β](https://developers.verida.network/docs/client-sdk/events#database-sync-changes)
Data is automatically synchronized from remote encrypted servers to the local client. Itβs possible to listen to events related to this syncing behavior:
```typescript
const listener = database.onSync('error', (err) => { console.log(err) })
listener.cancel()
```
A full list of events is available via the [PouchDB Documentation](https://pouchdb.com/api.html#sync)
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