Screenshot 1 of 1. MinecraftHub-generated editorial cover for Sonar, a voxel diorama around the lime MinecraftHub block
What Sonar works with.
| Platform | Java Edition |
|---|---|
| Loaders | BungeeCord, Folia, Paper, Purpur, Velocity, Waterfall, Bukkit, Spigot |
| Minecraft versions | 1.7.2, 1.16.5, 1.17.1, 1.18.2, 1.19.4, 1.20.6, 1.21.11, 26.1.2, 26.2, 26.3 |
Sonar is an anti-bot plugin for Paper, Folia, Purpur, Spigot and Bukkit servers, and for the Velocity, BungeeCord and Waterfall proxies. It analyses a player's behaviour before they reach the real server, so malicious traffic never lands on the backend. It is a server-side plugin only, and players join with a normal client.
Server software and versions
- BungeeCord, Folia, Paper, Purpur, Velocity and Waterfall: Minecraft 1.7.2 to 26.3. The newest build needs no dependencies.
- Bukkit and Spigot: Minecraft 1.7.2 to 1.21.11. The newest build needs no dependencies.
How the checks work
A first-time connection is sent to a lightweight fake server, where Sonar runs its verification. Four checks cover the ground.
- 1.New players are moved to the fake server on their first connection.
- 2.Movement must obey physics, including gravity and proper block collision.
- 3.Packets sent while interacting with vehicles such as boats must be legitimate.
- 4.Packets must match the vanilla protocol.
Sonar also queues incoming connections, which makes it technically impossible for a flood of bots to join at the same moment. Because the game uses TCP, packets arrive in order, so lag or high ping should not trip the check and cause false positives.
Installation
- 1.Pick the file that matches your software, whether a Paper-family server or a Velocity, BungeeCord or Waterfall proxy.
- 2.Drop the .jar into the plugins folder of that server or proxy. The general steps are in how to install plugins on a server.
- 3.Restart, then tune settings using the wiki at docs.jonesdev.xyz.
What Sonar leaves out
The design goal is a small feature set. Sonar shows no CAPTCHA to players and does not check for VPNs or proxies. If you need that kind of filtering, this is the wrong tool.
Sonar anti-bot plugin walkthrough in Spanish
Questions about Sonar.
4 questions
How do I install Sonar?
Place the Sonar .jar in the plugins folder of your Paper-family server, or of your Velocity, BungeeCord or Waterfall proxy, then restart. Players install nothing, since Sonar is a server-side plugin and they join with a normal client.
Does Sonar show a CAPTCHA to players?
No. One stated goal is that no player should be annoyed by any sort of CAPTCHA. Sonar verifies behaviour instead, checking physics, vehicle packets and protocol correctness in a fake server before the player reaches your real one.
Does Sonar work on Folia and Velocity?
Yes. Folia and Velocity both have their own builds listed on Modrinth, alongside Paper, Purpur, BungeeCord, Waterfall, Bukkit and Spigot. Pick the file that matches your software so the plugin loads on the right platform.
Does Sonar block VPN or proxy connections?
No. Sonar deliberately does not check for VPNs or proxies. It focuses on whether a connecting player behaves like a real one, using checks on physics and packets.
