Minecraft MCP Server

Instructions

Implementation Reference

• mcp-server/src/mcp-server.ts:250-291 (handler)

  Executes the leaveGame tool: disconnects bot(s) by username or all using BotManager.removeBot() or disconnectAll(). Returns success/error messages.

  if (name === "leaveGame") {
      try {
          const { username, disconnectAll } = args as { username?: string; disconnectAll?: boolean };
  
          if (disconnectAll) {
              const count = botManager.getBotCount();
              botManager.disconnectAll();
              return {
                  content: [{
                      type: "text",
                      text: `Disconnected all ${count} bot(s) from the game.`
                  }]
              };
          }
  
          if (!username) {
              throw new Error("Either 'username' or 'disconnectAll' must be specified");
          }
  
          const bot = botManager.getBotByUsername(username);
          if (!bot) {
              throw new Error(`No bot found with username '${username}'`);
          }
  
          botManager.removeBot(username);
  
          return {
              content: [{
                  type: "text",
                  text: `Bot '${username}' has been disconnected from the game.`
              }]
          };
      } catch (error) {
          return {
              content: [{
                  type: "text",
                  text: `Failed to leave game: ${error instanceof Error ? error.message : String(error)}`
              }],
              isError: true
          };
      }
  }

• mcp-server/src/mcp-server.ts:108-124 (schema)

  Input schema definition for the leaveGame tool, including username and optional disconnectAll parameters.

  {
      name: "leaveGame",
      description: "Disconnect a bot from the game",
      inputSchema: {
          type: "object",
          properties: {
              username: {
                  type: "string",
                  description: "The username of the bot to disconnect"
              },
              disconnectAll: {
                  type: "boolean",
                  description: "If true, disconnect all bots and close all connections"
              }
          }
      }
  }

• mcp-server/src/mcp-server.ts:84-135 (registration)

  Registers the leaveGame tool (along with joinGame) in the ListToolsRequest handler by including it in the static tools array.

  server.setRequestHandler(ListToolsRequestSchema, async () => {
      const tools = [
          {
              name: "joinGame",
              description: "Spawn a bot into the Minecraft game",
              inputSchema: {
                  type: "object",
                  properties: {
                      username: {
                          type: "string",
                          description: "The username for the bot"
                      },
                      host: {
                          type: "string",
                          description: "Minecraft server host (defaults to 'localhost' or command line option)"
                      },
                      port: {
                          type: "number",
                          description: "Minecraft server port (defaults to 25565 or command line option)"
                      }
                  },
                  required: ["username"]
              }
          },
          {
              name: "leaveGame",
              description: "Disconnect a bot from the game",
              inputSchema: {
                  type: "object",
                  properties: {
                      username: {
                          type: "string",
                          description: "The username of the bot to disconnect"
                      },
                      disconnectAll: {
                          type: "boolean",
                          description: "If true, disconnect all bots and close all connections"
                      }
                  }
              }
          }
      ];
  
      // Add all registered skills as tools
      const skillTools = skillRegistry.getAllSkills().map(skill => ({
          name: skill.name,
          description: skill.description,
          inputSchema: skill.inputSchema
      }));
  
      return { tools: [...tools, ...skillTools] };
  });