Fastmail MCP Server

Instructions

Implementation Reference

• src/index.ts:316-328 (registration)

  Registration of the 'get_calendar_event' tool including its description and input schema definition.
  name: 'get_calendar_event', description: 'Get a specific calendar event by ID', inputSchema: { type: 'object', properties: { eventId: { type: 'string', description: 'ID of the event to retrieve', }, }, required: ['eventId'], }, },
• src/index.ts:318-327 (schema)

  Input schema for the get_calendar_event tool, requiring eventId as string.
  inputSchema: { type: 'object', properties: { eventId: { type: 'string', description: 'ID of the event to retrieve', }, }, required: ['eventId'], },
• src/index.ts:849-864 (handler)

  MCP server request handler for 'get_calendar_event' that validates the eventId parameter, initializes the contacts/calendar client, calls getCalendarEventById, and formats the response as JSON text content.
  case 'get_calendar_event': { const { eventId } = args as any; if (!eventId) { throw new McpError(ErrorCode.InvalidParams, 'eventId is required'); } const contactsClient = initializeContactsCalendarClient(); const event = await contactsClient.getCalendarEventById(eventId); return { content: [ { type: 'text', text: JSON.stringify(event, null, 2), }, ], }; }
• src/contacts-calendar.ts:186-211 (handler)

  Core handler implementation in ContactsCalendarClient class: checks calendar permissions, constructs JMAP CalendarEvent/get request with the event ID, executes the request, and returns the event data.
  async getCalendarEventById(id: string): Promise<any> { // Check permissions first const hasPermission = await this.checkCalendarsPermission(); if (!hasPermission) { throw new Error('Calendar access not available. This account may not have JMAP calendar permissions enabled. Please check your Fastmail account settings or contact support to enable calendar API access.'); } const session = await this.getSession(); const request: JmapRequest = { using: ['urn:ietf:params:jmap:core', 'urn:ietf:params:jmap:calendars'], methodCalls: [ ['CalendarEvent/get', { accountId: session.accountId, ids: [id] }, 'event'] ] }; try { const response = await this.makeRequest(request); return response.methodResponses[0][1].list[0]; } catch (error) { throw new Error(`Calendar event access not supported: ${error instanceof Error ? error.message : String(error)}. Try checking account permissions or enabling calendar API access in Fastmail settings.`); } }