Entity ID Monitor (eidmon)

A Fabric mod that provides real-time visibility into Minecraft's internal Entity ID counter. Shows the current counter value, entity creation rate, and how far the counter is from a configurable threshold — with optional automation and debug tooling for players who need to work with the counter directly.

Overview

Every entity Minecraft spawned increments a single global integer: Entity.CURRENT_ID. For most players this number is invisible and irrelevant. For anyone investigating entity behavior, profiling spawn-heavy farms, or working on low-level entity research, it's the number that matters most — and the vanilla game gives you no "simple" way to see it.

eidmon makes it visible.

HUD

A persistent on-screen display showing:

• Counter — current value of the Entity ID counter
• Remaining — entities until the counter reaches your configured threshold
• Rate — entities created per second (wall-clock, unaffected by /tick rate)
• ETA — estimated time until threshold at current rate
• Mode — [SERVER] or [SINGLEPLAYER]
• Armed status — [ARMED] or [DISARMED]

Color changes as the counter approaches the threshold:

• White — normal
• Yellow (pulsing) — within alert distance (default: 1,000,000 remaining)
• Red — within warning distance (default: 10,000 remaining), with a center-screen warning

Toggle with F9 (rebindable).

Commands

Auto-Trigger

When armed, the mod performs a right-click at the player's crosshair the moment the counter reaches the configured threshold. The trigger is opt-in and the mod operates fully without ever arming it.

1. /eidmon threshold <value> — set the target
2. Aim your crosshair at whatever should be clicked (e.g. a lever)
3. /eidmon enable — arm
4. The mod fires the click when the counter hits the threshold

A sound plays when entering alert range and when the trigger fires.

Server Sync

When installed on both client and server, the mod syncs the real Entity.CURRENT_ID value from the server to all connected clients each tick — so the counter you see is exact, not estimated.

If the server doesn't have the mod, the client falls back to estimating the counter from the highest entity ID it has observed. Monitoring still works, but setcounter, collide, and debug are unavailable.

Configuration

Available via Mod Menu (requires Cloth Config) or in config/eidmon.json:

Installation

• Client + Server (recommended): install on both for exact counter values and full command support.
• Client only: works in singleplayer. On a dedicated server without the mod, the counter is estimated from observed entity IDs — monitoring works, but setcounter, collide, and debug are disabled.

Requires Fabric API. Optionally supports Cloth Config and Mod Menu for the settings screen.

Advanced Commands — Use At Your Own Risk

/eidmon setcounter and /eidmon collide directly manipulate the server's internal Entity ID counter. They require OP on servers and exist for testing and research into Entity ID Suppression.

If you don't know what Entity ID Suppression is, or what to expect from these commands, this mod is probably not for you. The monitoring and HUD features are completely safe — only setcounter and collide carry risk.

Misuse can cause:

• Entity ID collisions that crash the server
• Corrupted entity data that persists in saved chunks
• Worlds that become unloadable or irrecoverable

Always back up your world before experimenting. There is no undo.

On the Auto-Trigger

The arm/disarm auto-trigger exists to keep survival play mechanically vanilla. The mod never needs to touch server internals to use it — it simply watches the counter and simulates a right-click at the threshold, the same action a player would otherwise time by hand. setcounter and collide remain the escape hatch for testing and research, not the primary path.

Further Reading

What is Entity ID Suppression? That is out of scope for this description. If you wish to learn more, see Mikarific's channel — the person who first discovered and showcased it.