FTB Chunks: Claim Intrusion Alert

Vanilla FTB Chunks tells the intruder they can't break a block. This mod tells you (the claim owner) that someone tried.

When a non-team player tries to break / place / interact inside your FTB Chunks claim and the action is blocked, every online team member gets a one-line chat alert:

⚠ Alex tried to break a block at (210, 64, -88) in minecraft:overworld.

⏱ 5-minute cooldown per (intruder × claim) — no spam
🖥 Server-side only — clients don't need to install it
🧩 No mixin — uses FTB Chunks' public FTBChunksAPI
🛡 Silent fail — if FTB Chunks updates and the API shifts, the mod stays out of the way (no crashes, no log spam)

Why this exists

The vanilla FTB Chunks behaviour is one-sided: when an outsider tries to grief your claim, FTB Chunks shows them a message ("you can't do that here"). The claim owner gets nothing. You only find out something happened if you happen to check the log file later — or if a chunk goes missing.

FTB-Mods-Issues #257 requested exactly this feature. The FTB maintainer marked it "no longer planned for FTB". So this is a small drop-in mod that adds the missing notification.

Use cases

Private survival servers: catch friends-of-friends being rude before they get bored and leave
Public / whitelisted servers: detect raid attempts the moment they happen, not after the fact
Modpack servers (FTB, ATM, etc.): works inside any pack that ships FTB Chunks

How it works (technical)

The mod listens to vanilla BlockEvent.BreakEvent and PlayerInteractEvent.RightClickBlock at HIGHEST priority. When one of those events is canceled, it asks FTBChunksAPI.api().getManager().getChunk(...) whether the position is inside a claim. If yes, and the actor is not a team member, the team's online members get a chat message.

No per-player NBT, no save data, no command, no Item / Block registered. The only state is a small in-memory cooldown map, cleared on server stop.

Supported loaders / versions

Minecraft	NeoForge	Forge	Fabric
1.21.1	✅	—	—

Currently NeoForge 1.21.1 only, because FTB Chunks does not ship a Forge 1.21.1 build. A Fabric port is on the roadmap.

Dependencies

FTB Chunks ≥ 2101.0 (required)

Install

Install NeoForge 1.21.1
Install FTB Chunks
Drop claimintrusionalert-0.1.0.jar into mods/ (server side only; clients do not need it)

Languages

English, Japanese.

License

MIT — modpack inclusion welcome, no credit required.

Author: KURONAMI