Minecraft Bedrock MCP Server

Instructions

Implementation Reference

• src/server.ts:442-485 (registration)

  Registration of the 'execute_command' MCP tool, including schema definition (command: string) and handler function that calls executeCommand, optimizes result, adds hints, and formats MCP response.

  this.mcpServer.registerTool(
    "execute_command",
    {
      title: "Execute Command",
      description: "Execute a Minecraft command",
      inputSchema: {
        command: z.string().describe("The Minecraft command to execute"),
      },
    },
    async ({ command }: { command: string }) => {
      const result = await this.executeCommand(command);
  
      // トークン最適化: コマンド結果を要約
      const optimized = optimizeCommandResult(result.data);
  
      let responseText: string;
      if (result.success) {
        responseText = `✅ ${optimized.summary}`;
        if (optimized.details) {
          responseText += `\n\n${JSON.stringify(optimized.details, null, 2)}`;
        }
      } else {
        // エラーメッセージにヒントを追加
        const errorMsg = result.message || "Command execution failed";
        const enrichedError = enrichErrorWithHints(errorMsg);
        responseText = `❌ ${enrichedError}`;
      }
  
      // レスポンスサイズチェック
      const sizeWarning = checkResponseSize(responseText);
      if (sizeWarning) {
        responseText += `\n\n${sizeWarning}`;
      }
  
      return {
        content: [
          {
            type: "text",
            text: responseText,
          },
        ],
      };
    }
  );

• src/server.ts:630-652 (handler)

  Core handler logic for executing Minecraft commands via SocketBE World.runCommandAsync, handling world connection check and storing last response.

  public async executeCommand(command: string): Promise<ToolCallResult> {
    if (!this.currentWorld) {
      return { success: false, message: "No player connected" };
    }
  
    try {
      const result = await this.currentWorld.runCommand(command);
  
      // レスポンスをlastCommandResponseに保存（位置情報取得などで使用）
      this.lastCommandResponse = result;
  
      return {
        success: true,
        message: "Command executed successfully",
        data: result,
      };
    } catch (error) {
      return {
        success: false,
        message: `Command execution failed: ${error}`,
      };
    }
  }

• src/tools/base/tool.ts:133-146 (helper)

  BaseTool helper method for command execution, delegates to injected commandExecutor (server's executeCommand), used by modular tools.

  protected async executeCommand(command: string): Promise<ToolCallResult> {
      if (!this.commandExecutor) {
          return { success: false, message: 'Command executor not set' };
      }
      
      try {
          return await this.commandExecutor(command);
      } catch (error) {
          return { 
              success: false, 
              message: `Command execution error: ${error instanceof Error ? error.message : String(error)}` 
          };
      }
  }

• src/server.ts:447-449 (schema)

  Input schema definition for execute_command tool using Zod: command as required string.

  inputSchema: {
    command: z.string().describe("The Minecraft command to execute"),
  },