Grasscutter is a server software reimplementation for an anime game, written in Java and designed to run private servers.
The project addresses the desire to run a private instance of the game by reimplementing the server-side logic. It handles core gameplay systems including login, combat, friends lists, teleportation, the gacha system, cooperative play, monster spawning via console, and inventory management such as receiving items and characters and upgrading them. The implementation uses the KCP protocol for network communication.
Grasscutter suits developers and players interested in running private game servers or studying game server architecture. The project requires Java 17 and MongoDB Community Server to operate. It is version-locked to specific game releases; users must match their Grasscutter version to their game client version and cannot mix versions across different releases. The README does not compare the tool to alternatives.
The project is not actively maintained and has not kept pace with recent game updates beyond version REL4.0.1. The maintainers have explicitly stated they will not provide official support for beta or unofficial versions of the software, though community support remains available through Discord. A build workflow is configured and monitored through GitHub Actions.
