
Eye Spy
Server-sided ping and rangefinding functionality for the Spyglass, targeting Fabric & Quilt.
Screenshots




About this Mod
Archived
Eye Spy has been archived so I can stay focused on a smaller amount of mods for now. It was mainly intended to test a server-side library I was working on, and will need a basic full rewrite to bring to modern versions, ideally with Polymer as a backend instead.
Eye Spy
Server-sided ping and rangefinding functionality for the Spyglass, targeting Fabric & Quilt.
Features
All features do not require any installs on the client, and can be configured either in-game via the /eyespy config command
by operators, or by changing the config file config/eyespy.json5.
Ping


Players can now ping blocks and entities with the spyglass using a hijacked 'Swap Item with Offhand' keybind. This shows a glowing outline to them and surrounding players, as well as the distance, and optionally the description of the target. They can also double-tap the key to show a flashing red hazard ping.
For more details, see the Wiki Page.
Client Install
If a player installs Eye Spy on their client, then they will gain a dedicated keybind for pinging instead of overriding the 'Swap Item with Offhand' functionality. This is completely optional, and doesn't affect other players.
Rangefinder

When using the spyglass, players now see the distance to the hovered block or entity, along with their names if available.
For more details, see the Wiki Page.
Versions
Currently targeting 1.20.4, 1.20.2, 1.20.1 and 1.19.4. As this mod heavily uses Display Entities, a port to versions before would most likely require a rewrite.
Requirements
Bundles several JackFredLib modules and Server Translation API.
Available Versions
How to Install Eye Spy on Your Server
Order Server
Order a Minecraft Java server with at least 3 GB RAM (4 GB recommended).
Set fabric Loader
In the panel under "Egg", select the fabric loader and matching Minecraft version (1.21.4).
Install Mod
Open the mod browser in the dashboard and search for "Eye Spy". Click "Install" – done! Alternatively, upload the .jar via SFTP to the /mods folder.
Compatibility
Mod Loaders
Minecraft Versions
1.21.4, 1.21.3, 1.21.2 (+12 more)
Server-side
✓ RequiredRecommended RAM
4 GB(min. 3 GB)Frequently Asked Questions
Eye Spy server crashes on startup – what to do?
Most common cause: wrong fabric version or insufficient RAM. Check the server log (latest.log) for "OutOfMemoryError" or "Mixin" errors. With Mado Hosting: ensure at least 3 GB RAM is allocated and the loader matches the mod version (1.21.4). You can switch loaders with one click in the panel.
Is Eye Spy compatible with fabric and quilt?
Eye Spy officially supports fabric, quilt for Minecraft 1.21.4, 1.21.3, 1.21.2. The Mado dashboard automatically detects incompatible loader combinations.
Server lagging with Eye Spy – how to optimize performance?
Recommended RAM: 4 GB (per 8 players). Use /spark profiler to check if Eye Spy consumes the most tick time. Common fixes: reduce server view-distance to 8-10, install "performant" or "starlight" as supplementary mods on Forge. With Mado Hosting, your server runs on NVMe SSDs with dedicated CPU cores for minimal latency.
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