Yes. While with HTTP pipelining you can request them all over a single TCP connection using a single SSL session, you will need to make an HTTP request for each item you want.
If you're on a supported platform, the Firebase SDKs handle all this efficiently and can even provide real-time change notifications.
I'm trying to attach a ChildEventListener to the "item" Firebase and I'm getting a "permission denied" error. My guess is that I am doing something wrong, but on the off chance that the adding event listeners is not (yet) enabled, it would be nice to know. Any clues to what I might be doing wrong?
I've never used the Firebase API itself before. It's very clean!
Edit: I reached the same (now obvious) conclusion as mentioned in the reply below. Now my quick hack is working perfectly. Thank you so much for this!
[Firebase Dev Advocate] Glad you're enjoying Firebase! Attaching a listener to the "items" Firebase is disabled. This is because it would send every item from HN to your computer. You'll need to attach a listener to the individual item instead. The "permission denied" error is coming from the security rules on the HN Firebase (https://www.firebase.com/docs/security/quickstart.html). If you're trying to find out what the latest updates are, they're kept in the /updates node (https://github.com/HackerNews/API#changed-items-and-profiles).
If you're on a supported platform, the Firebase SDKs handle all this efficiently and can even provide real-time change notifications.