PacketEvents: what it is and how to update it

PacketEvents is a protocol library for Minecraft Java Edition: it gives plugins a clean way to read and send the packets the client and server exchange. It adds nothing for players. You install it because another plugin requires it — an anticheat, for example. It updates like any plugin: latest release from Modrinth → replace the `.jar` in `plugins/` → restart.

What PacketEvents is#

Why anticheats use a packet library#

The client and server talk in packets: movement, camera rotation, an attack, starting and finishing a block break, an inventory click — each action has its own packet. The regular plugin API (Bukkit) shows already-processed events like "player hit a mob", not the raw stream of packets in the order the client sent them.

You can reach raw packets without a library, but then the plugin digs into the server's internal classes, which change from version to version, and the author has to rewrite code for each one. A library takes that on: one API across every supported version and platform.

An anticheat lives on the packet stream. Timer shows up in the rate of movement packets, BadPackets in packets an honest client can't send. DGuard goes further: the team took the Minecraft 1.21.11 client apart down to the packet, and an honest client sends packets within a tick in a strict order. A cheat breaks it — KillAura, for example, turns the camera right before the hit — and lag can't do that. More in packet order.

How to install it#

1. 1

   Open the Modrinth page

   modrinth.com/plugin/packetevents, the Versions tab. Filter by the Paper loader and the Release channel.

2. 2

   Download the right file

   For Paper and Leaf it's packetevents-spigot-<version>.jar. The …-sources.jar next to it is source code for developers — don't put it on the server.

3. 3

   Put it into plugins/ and restart

   One copy per server: every plugin that needs it shares it. Check /plugins — PacketEvents should be green.

Release or dev build#

Releases go out on Modrinth, GitHub and SpigotMC. Between them, CodeMC's Jenkins builds developer builds with SNAPSHOT-style versions. They exist to test a fix before release, not to run on a server full of players.

DGuard runs on the latest PacketEvents release only; dev and SNAPSHOT builds won't do. You don't have to track it by hand: the DGuard panel takes the latest release from Modrinth, shows the PacketEvents status for each server and lets you know when it's time to update. From the console, /dguard license shows the version next to your plan and license state.

The latest release matters for more than bug fixes. Each PacketEvents version knows the protocols of specific Minecraft versions — Modrinth lists them for every file. Move the server to a new game version without a fresh PacketEvents release, and the plugins that rely on it may not understand the new packets.

How to update PacketEvents#

1. 1

   Check the current version

   /version packetevents in game or the console. With DGuard, /dguard license or the server card in the panel, which also shows the latest release.

2. 2

   Download the latest release

   From Modrinth, filtered to Paper + Release: packetevents-spigot-<version>.jar.

3. 3

   Swap the file

   Stop the server, delete the old packetevents-…jar from plugins/ and add the new one. Two versions in the folder mean errors on startup, guaranteed.

4. 4

   Start and check

   The server starts without errors, PacketEvents is green in /plugins, and the DGuard panel shows the new status. /reload won't do — restart: here's why.

PacketEvents on a server network#

On a BungeeCord or Velocity network, DGuard goes on every game server with its own key — so PacketEvents is needed on every game server next to it. The proxy itself only needs PacketEvents if a proxy plugin requires it: the project has separate builds for Velocity and BungeeCord. Network basics are in Velocity or BungeeCord.

"No PacketEvents" and other problems#

Other connection problems — the server doesn't show up in the panel, the key isn't accepted — are covered on the DGuard install page.

FAQ#