AntiBookBan
Paper anti-chunk ban plugin by Enea. A single jar compatible with Paper 1.21 → 1.26.2+.
What it does:
/scan <player>— scans a player's inventory (including offline players) and reports shulker boxes that exceed the limit (default 2 MB)./fixall— scans all player data of all worlds (including offline players) and deletes shulker boxes that exceed the limit. Before each modification it creates a<uuid>.dat.bakbackup.- Book limits — a book can have at most 25 pages and ASCII characters only (blocks the "weird" characters used for the exploit).
- Automatic scan on join — if a player joins with a suspicious shulker, operators are notified.
Compatibility
| Version | Player file | Status |
|---|---|---|
| 1.21 – 26.0 | <world>/playerdata/<uuid>.dat |
✅ tested on 1.21 |
| 26.1 – 26.2+ | <world>/players/data/<uuid>.dat |
✅ tested on 26.2 |
The plugin is compiled against the Paper 1.21 API (Paper maintains backward compatibility) and uses only stable APIs: no NMS, so the same jar runs across the whole range. Adventure NBT is shaded into the jar (relocated), so it does not depend on the server's classpath.
Commands and permissions
| Command | Description | Permission |
|---|---|---|
/scan <player> |
Scans inventory + armor + offhand + ender chest (online or offline) | antibookban.scan (op) |
/fixall |
Removes heavy shulkers from ALL player data (offline) and from online inventories | antibookban.fixall (op) |
/abb reload |
Reloads the config | antibookban.admin (op) |
Other permissions: antibookban.notify (receives join alerts, op by default).
Configuration
max-shulker-size: 2097152 # shulker limit in bytes (2 MB)
max-book-pages: 25 # maximum book pages
ascii-only: true # ASCII characters only in books
scan-on-join: true # notify ops if a player joins with suspicious shulkers
fix-ender-chest: true # /fixall also checks the ender chest
Note:
ascii-only: truealso blocks accented letters (è, à...). If you need them, set it tofalse.
How it works
- Online: each item is serialized to NBT with
ItemStack#serializeAsBytes(); if a shulker exceeds the limit, it is reported/removed. - Offline:
.datfiles are read/written directly with Adventure NBT (gzip), looking for shulkers in theInventoryandEnderItemslists and measuring the item's serialized NBT size. The infected files are precisely the huge ones, so an unlimited-size reader is used.
Future ideas
- Scan books in offline player data:
/fixallcurrently removes only heavy shulkers; it could be extended to also remove books with too many pages/non-ASCII characters. - Automatic removal on join: instead of alerting, remove the suspicious shulker immediately (config option).
- Detailed log: log file with date/time, player and slot for every removal.
- Whitelist/blacklist: exclude certain worlds or players from the scan.
- Discord/webhook notifications when
/fixallfinds something. - bStats for usage statistics.
