Eye Spy
Eye Spy is a server-side Minecraft mod that turns the humble spyglass into a genuine tactical tool. Instead of a novelty item that only zooms your view, the spyglass becomes a way to communicate with your team, mark threats, and measure distances precisely. Best of all, nobody on your server needs to install anything for the core features to work, which makes it one of the easiest multiplayer add-ons to roll out on a whim.
Originally built to test a server-side library, the project has since been archived by its author, who plans a full rewrite for modern versions with Polymer as a backend. That means the current builds are stable and fully playable on the versions they target, even if no further updates are coming. If you run a Fabric or Quilt server on a supported version, Eye Spy still delivers everything it promises.
What Eye Spy Does for Minecraft
The mod focuses on two connected features: pinging and rangefinding. Both are designed around the spyglass and both work entirely from the server side, so vanilla clients can join and participate without downloading a single file.
Ping Blocks and Entities
When you look through a spyglass and press the ping key, Eye Spy highlights whatever you are aiming at with a glowing outline that everyone nearby can see. The ping also displays the distance to the target and, if configured, its name or description. This makes calling out a distant mob, a hidden chest, or an enemy player base far more precise than shouting coordinates in chat.
By default, the mod hijacks the "Swap Item with Offhand" keybind, which is rarely used while scoping. Double-tapping the same key triggers a flashing red hazard ping, perfect for warning your group about incoming danger. Server operators can fine-tune all of this through the /eyespy config command in-game or by editing config/eyespy.json5 directly.
Rangefinder Functionality
Even without pressing any keys, the spyglass now shows the exact distance to whatever block or entity you hover over, along with its name when one is available. Builders can measure gaps across ravines, hunters can judge whether a shot is worth taking, and redstone engineers can plan layouts without pacing out every block by hand.
Client-Side Installation Is Optional
If a player does choose to install Eye Spy on their own client, they unlock a dedicated ping keybind instead of overriding the offhand swap. This is purely a quality-of-life improvement. It does not change how the mod behaves for anyone else on the server, so mixed lobbies of vanilla and modded clients work perfectly fine.
For players who prefer a frictionless setup, the foxygame.net launcher handles Eye Spy for Minecraft through its curated add-on catalog, matching the correct build to your game version and keeping it updated automatically so you never have to hunt down a matching jar yourself.
Supported Versions and Loaders
Eye Spy targets Fabric and Quilt, and the current builds are aimed at Minecraft 1.20.4, 1.20.2, 1.20.1, and 1.19.4. Because the mod leans heavily on Display Entities, porting it to versions older than 1.19.4 would essentially require a rewrite, which is part of why the author archived the project rather than backporting it.
Required dependencies include Fabric API, which bundles several JackFredLib modules along with the Server Translation API. Make sure these are present before starting your server, or the mod will fail to load.
How to Install Eye Spy
- Confirm your server runs Fabric or Quilt on 1.19.4, 1.20.1, 1.20.2, or 1.20.4.
- Download Eye Spy for Minecraft from the official project page and place the jar in your server's mods folder.
- Install Fabric API and any bundled libraries the mod requires.
- Restart the server and verify the mod loaded without errors in the console.
- Run /eyespy config in-game as an operator to adjust ping behavior, descriptions, and hazard settings.
Client installation follows the same steps but is entirely optional. If you only play on someone else's server, you can skip it and still see every ping and rangefinder readout.
Final Thoughts
Eye Spy is a smart, lightweight addition that gives the spyglass a real purpose in multiplayer. Its server-side design means zero barriers for your players, and the ping system genuinely improves coordination during exploration, PvP, and large builds. Although development has stopped, the existing releases remain a solid pick for any Fabric or Quilt server on a supported version, and the planned Polymer rewrite may eventually bring it back to modern Minecraft.