MCP-WTIT

Instructions

Implementation Reference

• src/infrastructure/mcp/time.server.ts:81-105 (handler)

  Direct handler for the 'get_current_time' tool call within the MCP server, invokes the use case and formats the MCP CallToolResult.

  private async handleGetCurrentTime(args: unknown): Promise<CallToolResult> {
    const input = this.parseTimeArguments(args);
    const result = await this.dependencies.getCurrentTimeUseCase.execute(input);
  
    if (!result.success || !result.data) {
      return {
        content: [
          {
            type: 'text',
            text: `Error: ${result.error || 'Failed to get current time'}`,
          } as TextContent,
        ],
        isError: true,
      };
    }
  
    return {
      content: [
        {
          type: 'text',
          text: JSON.stringify(result.data, null, 2),
        } as TextContent,
      ],
    };
  }

• src/infrastructure/mcp/time.server.ts:51-64 (schema)

  Input schema for the 'get_current_time' tool as returned in ListTools.

    type: 'object',
    properties: {
      includeMilliseconds: {
        type: 'boolean',
        description: 'Include milliseconds in the ISO8601 format (default: true)',
        default: true,
      },
      timezone: {
        type: 'string',
        description: 'Timezone for the time (default: UTC). Examples: "UTC", "America/New_York", "Asia/Tokyo"',
        default: 'UTC',
      },
    },
  },

• src/infrastructure/mcp/time.server.ts:46-67 (registration)

  Tool registration in handleListTools method, defines name, description, and schema for 'get_current_time'.

    tools: [
      {
        name: 'get_current_time',
        description: 'Get the current time with detailed information including ISO8601 format, timestamp, and timezone',
        inputSchema: {
          type: 'object',
          properties: {
            includeMilliseconds: {
              type: 'boolean',
              description: 'Include milliseconds in the ISO8601 format (default: true)',
              default: true,
            },
            timezone: {
              type: 'string',
              description: 'Timezone for the time (default: UTC). Examples: "UTC", "America/New_York", "Asia/Tokyo"',
              default: 'UTC',
            },
          },
        },
      } as Tool,
    ],
  };

• src/application/usecases/get-current-time.usecase.ts:5-33 (handler)

  Application use case handler invoked by the MCP tool handler, calls the domain time service.

  export class GetCurrentTimeUseCase implements IGetCurrentTimeUseCase {
    constructor(private readonly timeService: ITimeService) {}
  
    async execute(input?: IGetCurrentTimeUseCaseInput): Promise<IGetCurrentTimeUseCaseOutput> {
      try {
        const timeData = this.timeService.getCurrentTime({
          includeMilliseconds: input?.includeMilliseconds,
          timezone: input?.timezone,
        });
  
        return {
          success: true,
          data: timeData,
        };
      } catch (error) {
        if (error instanceof TimeServiceError) {
          return {
            success: false,
            error: error.message,
          };
        }
  
        return {
          success: false,
          error: 'An unexpected error occurred while retrieving the current time',
        };
      }
    }
  }

• src/domain/services/time.service.ts:11-20 (helper)

  Core helper function that computes and returns the current time data (ITimeData).

  getCurrentTime(options?: ITimeFormatOptions): ITimeData {
    const mergedOptions = { ...this.defaultOptions, ...options };
    const now = new Date();
    
    return {
      iso8601: this.formatToISO8601(now, mergedOptions),
      timestamp: now.getTime(),
      timezone: mergedOptions.timezone || this.getTimeZone(),
    };
  }