CreativeGuard

Server-side anti-cheat for Forge 1.20.1. Detects and punishes players carrying creative-only items, illegal NBT, or items whose lore / registry ID matches a configurable keyword list. No client install required — vanilla and modded clients connect normally.

Built for PvP and geopolitical servers where a single duped or cheated item can ruin a season. CreativeGuard scans every online player on a configurable interval and at login, and applies your chosen punishment on the first violation.

Features

Creative-only item blacklist — command blocks, chain/repeating command blocks, barriers, debug sticks, structure blocks, structure voids, jigsaw blocks, light blocks, bedrock, spawners, knowledge books, end portal frames, budding amethyst, reinforced deepslate, dirt paths, farmland-as-item, petrified oak slabs, and more. Fully editable.
Over-stacked items — flags any stack larger than its vanilla max size.
Over/under-enchanted items — catches enchantments above max level or below min level (Sharpness 10, Efficiency 32, negative levels, etc.).
Impossible attribute modifiers — inspects the AttributeModifiers NBT tag and flags modifiers whose absolute amount exceeds a configurable bound.
Keyword detection — whole-word, case-insensitive match of banned keywords in item lore and registry ID. Default list: creative, infinity, admin, debug, op, unbreakable, godmode, cheat, test.
4 punishment modes — permanent ban (default), tempban, kick, or silent confiscate. Swap at runtime with one command.
Exemptions — OP level threshold plus a named allowlist, both editable in-game.
Lightweight — ~17 KB jar, no client files, no mixins, no network traffic. Scan cost is negligible on modest player counts.

Installation

Install Forge 1.20.1 (≥ 47.2.0) on the dedicated server.
Drop creativeguard-1.0.0.jar into <server>/mods/.
Start the server once — this generates config/creativeguard-common.toml.
Edit the TOML (see below), then restart.

Clients do not need the mod installed. displayTest="IGNORE_ALL_VERSION" is set, so vanilla clients connect without a "mod mismatch" prompt.

Configuration

File: <server>/config/creativeguard-common.toml

`[general]`

Key	Default	Description
`punishment_mode`	`"BAN"`	`BAN` (permanent), `TEMPBAN`, `KICK`, or `CONFISCATE`.
`temp_ban_minutes`	`1440`	Duration for `TEMPBAN` mode (default = 24 hours).
`ban_reason`	`"Use of creative-only or illegal items (CreativeGuard)"`	Text shown on kick/ban.
`scan_interval_ticks`	`40`	Ticks between full sweeps. 20 ticks = 1 second.

`[exemptions]`

Key	Default	Description
`op_exempt_level`	`2`	Players with OP permission level ≥ this value are skipped. `-1` disables.
`exempt_players`	`[]`	Named allowlist. Case-insensitive.

`[detection]`

Key	Default	Description
`item_blacklist`	(see below)	Registry IDs treated as creative-only.
`name_keywords`	`["creative","infinity","admin","debug","op","unbreakable","godmode","cheat","test"]`	Whole-word, case-insensitive keyword flags.
`keyword_scan_fields`	`["lore","registry_id"]`	Where to scan. Valid: `display_name`, `lore`, `registry_id`.
`check_oversized_stacks`	`true`	Flag stacks above vanilla max size.
`check_over_enchanted`	`true`	Flag enchantments outside `[min, max]`.
`check_illegal_attributes`	`true`	Flag outsized `AttributeModifiers`.
`max_attribute_magnitude`	`50`	Absolute bound for modifier `Amount`.

Default blacklist

minecraft:command_block
minecraft:chain_command_block
minecraft:repeating_command_block
minecraft:command_block_minecart
minecraft:jigsaw
minecraft:structure_block
minecraft:structure_void
minecraft:barrier
minecraft:light
minecraft:debug_stick
minecraft:knowledge_book
minecraft:petrified_oak_slab
minecraft:farmland
minecraft:dirt_path
minecraft:budding_amethyst
minecraft:reinforced_deepslate
minecraft:bedrock
minecraft:end_portal_frame
minecraft:spawner
minecraft:nether_portal
minecraft:end_portal
minecraft:end_gateway

Example: switch to confiscate-only for a testing night

[general]
    punishment_mode = "CONFISCATE"
    scan_interval_ticks = 20

Example: tempban for a week, exempt your admin team

[general]
    punishment_mode = "TEMPBAN"
    temp_ban_minutes = 10080

[exemptions]
    op_exempt_level = 3
    exempt_players = ["masn", "Notch", "Admin_Bob"]

Example: paranoid keyword policy

[detection]
    name_keywords = ["creative","infinity","admin","debug","op","unbreakable","godmode","cheat","test","dupe","hack","kit","nuke"]
    keyword_scan_fields = ["display_name","lore","registry_id"]

Commands

All commands require OP permission level 2.

Command	Effect
`/creativeguard scan <player>`	Run a one-off manual scan.
`/creativeguard exempt add <name>`	Add a named player to the exempt list.
`/creativeguard exempt remove <name>`	Remove from the exempt list.
`/creativeguard exempt list`	Show the current exempt list.
`/creativeguard mode <BAN\\|TEMPBAN\\|KICK\\|CONFISCATE>`	Change punishment mode on the fly. Persists to the config file.
`/creativeguard reload`	Reminder that Forge hot-reloads the TOML on save.

Compatibility

Minecraft: 1.20.1
Loader: Forge 47.2.0 or newer (declared range [47,))
Physical side: dedicated server only. Deps are marked side="SERVER".
Client: no install needed. displayTest="IGNORE_ALL_VERSION".
Other mods: does not touch registries, block states, or world data — should coexist cleanly with any mod in the 1.20.1 ecosystem.

FAQ

Will it ban players who pick up a spawner with Silk Touch? Spawners can't be picked up with Silk Touch in vanilla. If a mod adds that ability and you want to allow it, remove minecraft:spawner from item_blacklist.

What if I name my sword "Creative Fury"? It'll match the creative keyword. Either rename the item, add yourself to exempt_players, or trim the keyword list.

Does it scan Ender Chests / Shulker Boxes? Not in 1.0.0 — only the main inventory, armor, and offhand. Planned for a later release.

Can I disable a specific check? Yes. Every check has a toggle under [detection]. Set check_over_enchanted = false to skip enchant checks, etc.

How do I know the mod is running? Server log will show [CreativeGuard] Initialized. on startup. Flagged players also produce a log line and a broadcast to online ops.

Credits

Built for Project Atlas. Server-side anti-cheat for Forge 1.20.1.

Creative Guard