Earn it. Bank it. Defend it.
A full in-game economy for Minecraft 1.21.1 / NeoForge 21.1.235 — quests to earn from, a market that reacts to what you sell, banknotes you can hold, and vaults other players can crack open.
Mod id coinkeep. Published by SapperSquad.
Everything lives in one item, the Coinkeep Ledger. You are given one the first time you join; craft another with a book + a gold nugget. Press J to open it anywhere, or K to open it straight on the Shop tab.
Four tabs: Quests, Shop, Cash, Guide.
180 quests across 10 chapters — Mining, Combat, Tools & Armor, Building, Farming, plus one chapter per vanilla advancement tab (Story, Nether, The End, Adventure, Husbandry), so the book covers the whole base game.
- Nothing to accept. Play, and progress tracks itself.
- Gathering quests repeat forever on escalating tiers. Progress is a lifetime running total that is never reset — mine 40 iron and all 40 count toward the next threshold. Later tiers pay more in total but slightly less per item, so it always pays to spread out.
- Almost nothing is gated. Only 10 dependencies exist in the whole book, and each is a real requirement (crafting tiers; the Wither needs skulls from wither skeletons; a beacon needs a nether star).
- Quests sort by what is actionable: in progress, untouched, locked, then complete.
- Two ladders show progression — the tier ladder inside a quest, and the chapter ladder across its siblings. Hover any pip for its exact requirement and payout.
- Buy from a categorised catalog, cheapest first, priced green or red by affordability. Categories include Rare (Elytra, Totem, Nether Star…) and Signature — named, pre-enchanted endgame gear like The Prospector at $210,000.
- Sell your haul. Each sale saturates that item's demand, so it pays a little less than the last, and demand recovers over time. Grinding one block forever stops being worth it without anything ever being locked.
- Demand is per player, so nobody can crash the market for everyone else.
- Buy prices are fixed, and the spread means buying and re-selling can never be a money loop.
- Anything enchanted or renamed is unsellable, so a $210k named tool can never be cashed in at the price of a plain one.
18 banknote denominations, $1 to $100,000,000.
- Withdraw your balance as notes; shift-click for as many as you can afford.
- Deposit all bills banks everything you are carrying at once.
- Your banked balance survives death. Cash in your pockets does not.
/paysends money directly; handing over notes works too.
- Craft a vault (4 iron blocks, 4 gold blocks, 1 diamond block). Money inside is never lost on death, even where the server drops balances.
- Only the owner can open it — and only the owner can break it. A thief cannot destroy someone's savings.
- Breaking your own vault returns it as an item with the money still inside, so you can relocate. The tooltip shows the amount.
- Carrying a loaded vault is the risk: it is an ordinary item, so dying drops it, and whoever loots it gets a locked vault they must crack.
- A Vault Cracker (netherite-tier, consumed on use) is the only way to rob one. You cannot see how much is inside before committing. Cracking also clears the claim, so the emptied vault can then be broken and taken.
Every quest, chapter and shop entry is a JSON file in a datapack registry, so a modpack can
add, retune or override anything without touching the jar. /reload applies changes live.
data/<namespace>/coinkeep/quest_line/<id>.json
data/<namespace>/coinkeep/quest/<id>.json
data/<namespace>/coinkeep/shop_entry/<id>.json
A quest is usually this short — name and icon are optional and derived from the trigger, so nothing ever renders unnamed or icon-less:
{
"id": "mine_coal",
"line": "mining",
"trigger": "block_break",
"target": "minecraft:coal_ore",
"count": 32,
"rewards": [ { "type": "money", "amount": 200 } ]
}Quest fields: trigger is one of block_break, mob_kill, item_craft, advancement.
Optional: name, description, icon, dependencies, max_tier (1 = one-shot,
0 = repeats forever), target_growth, reward_growth.
Reward types — every reward states what it gives, so a command reward never renders as the bare word "command":
{ "type": "money", "amount": 500 }
{ "type": "item", "item": "minecraft:diamond", "count": 3 }
{ "type": "command", "command": "effect give @p minecraft:resistance 600 1",
"label": "10 min Resistance II", "icon": "minecraft:potion" }Shop entries take category, item, count, price, and optionally sell_price
(defaults to 40% of the per-unit buy price), saturation, name, and an enchantments
list for pre-enchanted gear. Items from any other mod work by id.
Content is validated on server start and on every /reload: dangling dependency ids,
duplicate ids and dependency cycles are all reported, because a typo would otherwise leave a
quest silently unreachable.
| Command | Purpose |
|---|---|
/balance |
Show your balance |
/buy <id> |
Buy a catalog entry |
/sell <id> [qty] |
Sell items at the current market price |
/pay <player> <amount> |
Send money to another player |
/withdraw <denom> [qty] |
Turn balance into banknotes |
/depositall |
Bank every note you are carrying |
/addbalance <player> <amount> |
Op-only; for other mods' reward systems |
serverconfig/coinkeep-server.toml, per world. Hot-reloads.
| Setting | Default | Effect |
|---|---|---|
dropBalanceOnDeath |
false |
Convert a dying player's balance into notes at the death site |
balanceDropPercent |
100 |
How much drops, when the above is on |
respectKeepInventory |
true |
The keepInventory gamerule also protects the balance |
vaultOwnerOnly |
true |
Only the placer can open a vault |
allowVaultCracking |
true |
Set false to make vaulted money completely untakeable |
giveBookOnFirstJoin |
true |
Hand every new player a Ledger |
Requires JDK 21.
./gradlew build # produces build/libs/coinkeep-1.0.0.jar
./gradlew runClient # dev client
Quest and shop content only loads once a world loads, so a client sitting at the title screen proves nothing. To boot straight into a world for testing:
./gradlew runClient -PquickPlay="New World"
- No custom network packets. Balance, quest progress and market saturation all ride
NeoForge synced data attachments; the vault GUI uses vanilla's
clickMenuButton. That is also why the datapack registries are declared with a network codec — a server-only registry would leave the client's book empty. - Quest progress is keyed by string id, so renaming a quest in JSON resets that quest's progress rather than corrupting a save.
- A vault's money and owner live on the item via a data component, which is what lets a broken vault be carried, dropped on death, and still need cracking by whoever finds it.