Fastmail MCP Server

Instructions

Implementation Reference

• src/index.ts:146-163 (schema)

  Tool schema definition including name, description, and input schema for list_emails
  { name: 'list_emails', description: 'List emails from a mailbox', inputSchema: { type: 'object', properties: { mailboxId: { type: 'string', description: 'ID of the mailbox to list emails from (optional, defaults to all)', }, limit: { type: 'number', description: 'Maximum number of emails to return (default: 20)', default: 20, }, }, }, },
• src/index.ts:674-685 (handler)

  MCP tool handler for 'list_emails' that extracts parameters and calls JmapClient.getEmails
  case 'list_emails': { const { mailboxId, limit = 20 } = args as any; const emails = await client.getEmails(mailboxId, limit); return { content: [ { type: 'text', text: JSON.stringify(emails, null, 2), }, ], }; }
• src/jmap-client.ts:96-120 (handler)

  Core implementation of email listing using JMAP protocol: queries emails optionally filtered by mailbox, sorted by receivedAt descending, fetches specified properties.
  async getEmails(mailboxId?: string, limit: number = 20): Promise<any[]> { const session = await this.getSession(); const filter = mailboxId ? { inMailbox: mailboxId } : {}; const request: JmapRequest = { using: ['urn:ietf:params:jmap:core', 'urn:ietf:params:jmap:mail'], methodCalls: [ ['Email/query', { accountId: session.accountId, filter, sort: [{ property: 'receivedAt', isAscending: false }], limit }, 'query'], ['Email/get', { accountId: session.accountId, '#ids': { resultOf: 'query', name: 'Email/query', path: '/ids' }, properties: ['id', 'subject', 'from', 'to', 'receivedAt', 'preview', 'hasAttachment'] }, 'emails'] ] }; const response = await this.makeRequest(request); return response.methodResponses[1][1].list; }