Features

One job, done every server tick.

The core loop

Twenty times a second (once per server tick), the mod looks at every online player and collects each XP orb inside the configured radius around them. That is the whole mod. There are no keybinds to press, no GUI to open, and nothing to toggle in game.

Vanilla pickup, minus the walking

Collection goes through vanilla's own orb pickup code, the same code that runs when you step on an orb yourself. That means:

The mod only removes two annoyances: having to physically touch each orb, and vanilla's two-tick breather between orbs. That breather is why a big farm drop used to take ages; InstantXP skips it, so a whole pile is absorbed in a single tick.

What it leaves alone

Performance

Per player per tick, the mod does one bounding-box lookup for nearby orbs and then touches what it finds. When there is nothing in range, that is the entire cost, which is negligible next to everything else a server tick already does. There are no background threads and nothing runs on the client.