Chunkis

# Smaller world saves without changing gameplay Worlds grow quietly. Regions, block entities, entities, and repeated chunk data can make backups, transfers, and long-term storage heavier than expected. **Chunkis gives Minecraft a dedicated chunk storage layer designed to keep world data compact and recoverable.** ## What Chunkis does Chunkis replaces vanilla chunk persistence with its own CIS format. It: - stores Chunkis-owned ("claimed") chunk data in compact region files — chunks Chunkis has taken over as the authoritative source, as opposed to chunks still owned by vanilla's Anvil format; - restores blocks, block entities, entities, and supported metadata when chunks load; - protects vanilla saves that haven't been claimed by Chunkis from being overwritten; - rejects unsafe or incomplete chunk payloads; - supports importing existing vanilla worlds through its migration path; - works with singleplayer worlds and integrated (LAN-hosted) servers. **Dedicated servers:** Chunkis has not been tested on dedicated server setups. If you're running a standalone/dedicated server (not a LAN world hosted from the client), treat this as unsupported until stated otherwise. Chunkis changes how chunks are stored. It does not add gameplay content, change recipes, or replace rendering. ## Why use it? | Benefit | What it means | |---|---| | **Smaller worlds in many cases** | CIS can avoid redundant storage, but the result depends on the world — see (#storage-impact). | | **Easier backups** | Smaller saves are faster to copy, upload, archive, and transfer. | | **Safer, predictable persistence** | Chunkis validates ownership and rejects data that can't be reconstructed safely, so restored state is deliberate rather than dependent on accidental vanilla behavior. | | **No fake performance promises** | Chunkis is a storage mod — not an FPS or TPS booster. | ## Requirements - Minecraft `1.21.11` - Fabric Loader - Fabric API - Java 21 or newer ## Installation 1. Install (https://fabricmc.net/use/) for Minecraft `1.21.11`. 2. Download (https://modrinth.com/mod/fabric-api) and Chunkis from (#) / (#) *(links TBD)*, or grab the latest release from (https://github.com/Liparakis/Chunkis/releases). 3. Place both `.jar` files in your `.minecraft/mods` folder (or your server's `mods` folder, for integrated/LAN hosting). 4. Launch with the Fabric profile. ## Compatibility Chunkis has not been tested against other mods that write or optimize chunk/region data (e.g. lighting engine replacements, other chunk-storage or compression mods). If you're running mods in that category, back up before testing and report any conflicts you find. ## Important: Beta software Before installing: 1. Make a complete backup of your world. 2. Test on a copy or a new world first. 3. Restart the world and verify blocks, block entities, entities, and dimensions. 4. Keep the backup until you are satisfied with the result. **Uninstalling Chunkis is not an automatic rollback.** If you need to return to vanilla storage, restore the backup made before Chunkis became authoritative. ## Existing worlds Chunkis can import existing vanilla MCA data through its integrated-server migration path. The migration checks both normal chunk regions and external entity regions. Source files are only retired after the migrated data is validated and a verified backup is created. If your world already contains authoritative CIS data, Chunkis treats leftover vanilla region files as stale takeover data. Always keep a backup before allowing this transition. ## Storage impact Chunkis does not guarantee that every world will become smaller. Storage results depend on: - terrain and block-state variety; - block entities; - entities; - world history; - other mods that write chunk data. **Benchmark:** !(https://cdn.modrinth.com/data/cached_images/4316e6145dc9680f75ef1a6fd3a1812360579c66.png) A freshly generated, unplayed 2000×2000 region (via Chunky) stored **603 MB** in vanilla's region files plus **13.2 MB** in its separate entities folder (**616.2 MB** combined), vs **70 MB** in Chunkis 4.0.0's combined format (region + entities together) — an **~88.6%** reduction. This is a single benchmark on an unplayed world; played worlds with more block entities and terrain variety will see different results. Community-submitted benchmarks on real, played worlds are welcome — (https://github.com/Liparakis/Chunkis/issues) with your numbers. ## FAQ ### Will Chunkis improve FPS or TPS? No general improvement is promised. Chunkis focuses on chunk storage, save/load behavior, and persistence safety. ### Is Chunkis always smaller than vanilla? No — see (#storage-impact). ### Does Chunkis change gameplay? It does not add gameplay content. It changes how chunk data is persisted and restored. ##