Real Mobcap

Simple server-side mobcap control for Minecraft (Fabric).

Patches MobCategory so the spawn engine, Carpet and the built-in command all see the same values. JSON config only.

Inspired by the idea behind Proper Mobcap Modifier (getter overrides for spawn groups), reimplemented for 26.3 with field patching and a diagnostic command (inspired by Carpet).

Config

config/realmobcap.json (written on first run with vanilla defaults)

{
  "enabled": true,
  "categories": {
    "monster": {
      "max": 70,
      "friendly": false,
      "persistent": false,
      "despawnDistance": 128,
      "noDespawnDistance": 32
    },
    "creature": { "max": 10, "friendly": true, "persistent": true, "despawnDistance": 128, "noDespawnDistance": 32 },
    "ambient": { "max": 15, "friendly": true, "persistent": false, "despawnDistance": 128, "noDespawnDistance": 32 },
    "axolotls": { "max": 5, "friendly": true, "persistent": false, "despawnDistance": 128, "noDespawnDistance": 32 },
    "underground_water_creature": { "max": 5, "friendly": true, "persistent": false, "despawnDistance": 128, "noDespawnDistance": 32 },
    "water_creature": { "max": 5, "friendly": true, "persistent": false, "despawnDistance": 128, "noDespawnDistance": 32 },
    "water_ambient": { "max": 20, "friendly": true, "persistent": false, "despawnDistance": 64, "noDespawnDistance": 32 },
    "misc": { "max": -1, "friendly": true, "persistent": true, "despawnDistance": 128, "noDespawnDistance": 32 }
  }
}

Omit any field to keep the vanilla value. Restart after editing.

Command

/realmobcap
/realmobcap show

Op level 2. Shows count / effective cap for the current dimension (same formula as the spawn engine), plus per-chunk max and flags.