First release.

Trades a configurable physical item for GriefPrevention claim blocks. No Vault, no balances: the item leaves the inventory and the blocks land in GriefPrevention's bonus pool.

Requires GriefPrevention 16.18.7+ and Paper 1.21+. Verified running on Paper 26.2.

/claimbarter buy <items>     pay items, receive claim blocks
/claimbarter sell <blocks>   sell bought blocks back at the refund rate
/claimbarter info            current rate and your holdings

The amount is always what you hand over: buying is priced in items, selling in claim blocks.

Currency item, blocks per item, refund ratio, a purchase ceiling and every message are configurable. Bad values are refused at load with a reason in the console rather than half-applied.

sha256 of the jar: fe1c4a26feef6d4375be7be518a1e6f5acf7d865e4b9bd6f746f2d6ed964836a