Minecraft Server MCP

Instructions

Implementation Reference

• src/tools/world-tools.ts:168-216 (handler)

  Registration and implementation of the set_world_spawn MCP tool. It verifies the server is not running before using worldManager.modifyLevelDat to update the spawn coordinates.

  server.tool(
    "set_world_spawn",
    "Set the world spawn point by modifying level.dat. The server must be stopped.",
    {
      world_name: z.string().describe("World folder name"),
      x: z.number().describe("X coordinate"),
      y: z.number().describe("Y coordinate"),
      z: z.number().describe("Z coordinate"),
    },
    async ({ world_name, x, y, z: zCoord }) => {
      if (manager.isRunning()) {
        return {
          content: [
            {
              type: "text",
              text: "Cannot modify level.dat while the server is running. Use the /setworldspawn command via execute_command instead, or stop the server first.",
            },
          ],
          isError: true,
        };
      }
  
      try {
        await worldManager.modifyLevelDat(world_name, {
          SpawnX: x,
          SpawnY: y,
          SpawnZ: zCoord,
        });
        return {
          content: [
            {
              type: "text",
              text: `World spawn for "${world_name}" set to X:${x} Y:${y} Z:${zCoord}.`,
            },
          ],
        };
      } catch (error) {
        return {
          content: [
            {
              type: "text",
              text: `Error: ${error instanceof Error ? error.message : String(error)}`,
            },
          ],
          isError: true,
        };
      }
    }
  );