Drop Stacker

Drop Stacker v1.1.0 now targets Minecraft 26.2, merges drops instantly instead of on a scan interval, and cuts the cost of the neighbour scan considerably.

Still server-side only — vanilla clients see stack counts and despawn timers with no mod installed.

Minecraft 26.2

Requires Minecraft 26.2, Fabric Loader 0.19.3+, Fabric API, Fabric Language Kotlin, and Java 25. Minecraft 26.1.2 users stay on v1.0.1; that version is preserved on the 26.1.2 branch.

Instant merging

Merging is now push-based: a new drop is absorbed into a nearby pile in the tick it spawns, rather than waiting for the next scan. Each pass also drains every compatible neighbour instead of one per scan — collapsing a 100-item pile previously took roughly 500 ticks no matter how low scanInterval was set, and is now a single pass.

Performance

• Blacklist, whitelist and overrides resolve to registry references once at load. The scan predicate previously allocated a string for every candidate of every scan, even with an empty blacklist.
• Neighbour queries use a shared scratch list with a hard limit, instead of allocating a list of every match to then keep one.
• Scans stagger per entity, so a mob's drops no longer all scan on the same tick.
• Idle piles progressively back off to maxScanInterval, which is safe now that new drops push into piles on spawn.
• Vanilla's own 40-tick merge scan is cancelled, so only one merge system runs.
• The name-tag label is rebuilt only when its rendered text would actually change.

Fixes

• Merged counts never synced to clients. Counts were mutated in place, but the entity data tracker compares by equality, so the change was never sent. Merging now builds a new stack and goes through setItem, as vanilla's own merge does.
• Items could not merge for the first half-second after being dropped — the pickup-delay check was stricter than vanilla's.
• Large stacks bypassed vanilla's infinite-lifetime and near-despawn guards; both are re-asserted.
• Item entities with their own custom name are no longer relabelled or silently absorbed into a neighbouring pile.

New

• /dropstacker reload | stats | resetstats | toggle | set <field> <value> (permission level 2) — tune and reload without a restart.
• Item tags (#minecraft:logs) in blacklist and the new whitelist, plus per-item maxStackSize overrides.
• New config: enabled, mergeOnSpawn, maxScanInterval, maxMergePerPass, ageInheritance, labelMode, and radius/verticalRadius. Existing scanRadiusX/Y/Z configs migrate automatically on first load.

Note on ageInheritance

The default YOUNGEST preserves 1.0.x behaviour: a pile inherits the longest remaining lifetime when it absorbs a drop, so a pile fed by a farm never despawns. Set KEEP_RECEIVER for vanilla despawn behaviour.

Testing

Verified on a live 26.2 server: merge-on-spawn, stack cap and remainder handling, blacklist by id and by tag, per-item overrides, hot reload, pickup-delay and infinite-lifetime guards, and named-item exclusion.

The periodic tick scan and the adaptive backoff have had less coverage than the rest — a dev server with no player connected does not tick item entities, so those paths were exercised manually rather than systematically. Please open an issue if you see anything off.