Sleep MCP Server

Instructions

Implementation Reference

• src/services/sleep.ts:10-16 (handler)

  Core handler logic for the sleep tool: validates input milliseconds and performs the sleep using setTimeout.

  async sleep(ms: number): Promise<void> {
    if (isNaN(ms) || ms < 0) {
      throw new Error("milliseconds must be a non-negative number");
    }
    
    return new Promise(resolve => setTimeout(resolve, ms));
  }

• src/index.ts:56-77 (handler)

  MCP server handler for CallToolRequestSchema, specifically handles the 'sleep' tool by extracting milliseconds, calling the service, and returning success content.

  server.setRequestHandler(CallToolRequestSchema, async (request) => {
    if (request.params.name !== "sleep") {
      throw new McpError(ErrorCode.MethodNotFound, "Unknown tool");
    }
  
    try {
      const ms = Number(request.params.arguments?.milliseconds);
      await service.sleep(ms);
  
      return {
        content: [{
          type: "text",
          text: `Waited for ${ms} milliseconds`
        }]
      };
    } catch (error) {
      throw new McpError(
        ErrorCode.InvalidParams,
        error instanceof Error ? error.message : "Unknown error"
      );
    }
  });

• src/index.ts:33-49 (schema)

  Input schema definition for the sleep tool: requires 'milliseconds' as a non-negative number.

      {
        name: "sleep",
        description: "Wait for a specified duration",
        inputSchema: {
          type: "object",
          properties: {
            milliseconds: {
              type: "number",
              description: "Duration to wait in milliseconds",
              minimum: 0
            }
          },
          required: ["milliseconds"]
        }
      }
    ]
  };

• src/index.ts:30-50 (registration)

  Registration of the sleep tool via the ListToolsRequestSchema handler, which returns the tool metadata including schema.

  server.setRequestHandler(ListToolsRequestSchema, async () => {
    return {
      tools: [
        {
          name: "sleep",
          description: "Wait for a specified duration",
          inputSchema: {
            type: "object",
            properties: {
              milliseconds: {
                type: "number",
                description: "Duration to wait in milliseconds",
                minimum: 0
              }
            },
            required: ["milliseconds"]
          }
        }
      ]
    };
  });

• src/services/sleep.ts:4-16 (helper)

  SleepService class providing the sleep functionality as a helper for the main handler.

  export class SleepService {
    /**
     * Wait for the specified duration
     * @param ms Duration to wait in milliseconds
     * @returns Promise that resolves after the duration
     */
    async sleep(ms: number): Promise<void> {
      if (isNaN(ms) || ms < 0) {
        throw new Error("milliseconds must be a non-negative number");
      }
      
      return new Promise(resolve => setTimeout(resolve, ms));
    }