Minecraft Java MCP Server (Fabric)

Install the mod from Modrinth or CurseForge. Pick the jar that matches your Minecraft version, drop it in mods/ alongside Fabric API, and launch. Full walkthrough in Quick start below.

A Model Context Protocol (MCP) server that runs inside Minecraft Java Edition as a Fabric mod. It exposes the server-side Minecraft API and the Fabric API as MCP tools so an MCP client — Claude Desktop, Cursor, or any agent that speaks MCP — can read and manipulate a live world programmatically.

An agent built this over MCP — authored as a parametric voxel model, then placed in a single block_fill_batch and verified with block_render_region (the server-side render that produced no screenshot dependency — it reads block map colours straight from the world).

And Ghasticlawd — the project’s Ghast × Claude mascot — voxelized, placed via block_fill_batch, and confirmed with block_render_region.

And terrain, too — this red-rock canyon, inspired by the national parks of the American West, was generated as a hydraulically eroded heightfield, render-checked, then materialized into the world through block_fill_batch and verified with block_render_region.

The mod ships separate jars for each supported Minecraft version. The build matrix is 1.21.11, 26.1.1, 26.1.2, 26.2, and 26.3.

Two endpoints: world + inspection

The same jar exposes two MCP servers. The main entrypoint serves the world tools on minecraft-java (default port 8765) wherever a server runs — dedicated or single-player. The client entrypoint runs inside a real, rendered client and serves an inspection-only surface on minecraft-java-client (default port 8766): view_capture returns the player’s actual first-person frame as a PNG, and sense_* / client_status read client-side perception. It is the