Minecraft Bedrock MCP Server

Instructions

Implementation Reference

• src/server.ts:404-439 (registration)

  Registration of the 'send_message' MCP tool, including Zod input schema and async handler that delegates to server.sendMessage and returns formatted response.

  this.mcpServer.registerTool(
    "send_message",
    {
      title: "Send Message",
      description:
        "Send a chat message to the connected Minecraft player. ALWAYS provide a message parameter. Use this to communicate with the player about build progress or instructions.",
      inputSchema: {
        message: z
          .string()
          .describe(
            "The text message to send to the player (REQUIRED - never call this without a message)"
          ),
      },
    },
    async ({ message }: { message: string }) => {
      const result = await this.sendMessage(message || "Hello from MCP server!");
  
      let responseText: string;
      if (result.success) {
        responseText = result.message || "Message sent successfully";
      } else {
        // エラーメッセージにヒントを追加
        const errorMsg = result.message || "Failed to send message";
        responseText = `❌ ${enrichErrorWithHints(errorMsg)}`;
      }
  
      return {
        content: [
          {
            type: "text",
            text: responseText,
          },
        ],
      };
    }
  );

• src/server.ts:592-613 (handler)

  Core handler method that sends the message to the current Minecraft world/player, with connection checks, logging, and error handling.

  public async sendMessage(text: string): Promise<ToolCallResult> {
    if (!this.currentWorld) {
      if (process.stdin.isTTY !== false) {
        console.error("エラー: プレイヤーが接続されていません");
      }
      return { success: false, message: "No player connected" };
    }
  
    try {
      if (process.stdin.isTTY !== false) {
        console.error(`メッセージ送信: ${text}`);
      }
  
      await this.currentWorld.sendMessage(text);
      return { success: true, message: "Message sent successfully" };
    } catch (error) {
      if (process.stdin.isTTY !== false) {
        console.error("メッセージ送信エラー:", error);
      }
      return { success: false, message: `Failed to send message: ${error}` };
    }
  }

• src/server.ts:406-416 (schema)

  Input schema for the 'send_message' tool: requires a string 'message' validated with Zod.

  {
    title: "Send Message",
    description:
      "Send a chat message to the connected Minecraft player. ALWAYS provide a message parameter. Use this to communicate with the player about build progress or instructions.",
    inputSchema: {
      message: z
        .string()
        .describe(
          "The text message to send to the player (REQUIRED - never call this without a message)"
        ),
    },