example-mcp-server-stdio

Instructions

Implementation Reference

• src/server.ts:575-578 (schema)

  Output schema definition for the demo_progress tool, defining structured output with message and progressSteps array using Zod validation.

  const demoProgressOutputSchema = {
    message: z.string(),
    progressSteps: z.array(z.number()),
  };

• src/server.ts:580-587 (registration)

  Registration of the demo_progress tool with server.registerTool, including empty input schema and reference to output schema.

  server.registerTool(
    'demo_progress',
    {
      title: 'Demo Progress',
      description: 'Demonstrate progress notifications with 5 updates',
      inputSchema: {},
      outputSchema: demoProgressOutputSchema,
    },

• src/server.ts:588-619 (handler)

  Handler function for demo_progress tool that simulates progress by sending 5 notifications with increasing progress (20%,40%,etc.) using sendNotification, then returns completion message with structured content.

    async (_, { sendNotification }) => {
      log.info('Executing demo_progress');
      requestCount++;
  
      const progressId = 'demo-progress-task';
  
      for (let i = 1; i <= 5; i++) {
        await new Promise((resolve) => setTimeout(resolve, 500));
        await sendNotification({
          method: 'notifications/progress',
          params: {
            progressToken: progressId,
            progress: i * 20,
            message: `Step ${i} of 5 - Processing complex calculations...`,
          },
        });
      }
  
      return {
        content: [
          {
            type: 'text',
            text: 'Progress demonstration completed',
          },
        ],
        structuredContent: {
          message: 'Progress demonstration completed',
          progressSteps: [20, 40, 60, 80, 100],
        },
      };
    },
  );