**Server-sent events** enable servers to push data to the web client using a long-term persistent connection with the server. This connection is unidirectional, so clients cannot send events to a server.

Server-sent events use JavaScript's EventSource API to continuously push messages to the client.

For example, the following code creates an ```EventSource``` object and registers an event listener:
```
var source = new EventSource('serverUpdates.aspx');
source.onmessage = function (event) {
  alert(event.data);
};
```

On the server-side, the script ("serverUpdates.aspx" in this case) sends messages in the form of text/event-stream MIME type. Each notification is sent as a block of text terminated by a pair of newlines:

```
data: message 1.

data: message 2.

data: message 3.
```
 

# Applications of server-sent events
- Stock price updates are a good use case for SSEs, as the server has to send frequent updates to the client.
- SSEs can also be used for server-monitoring services.

- Real-time social media feeds, news updates, or alerts can also be updated using server-sent events.


What are HTTP server-sent events?

Applications of server-sent events