hermes-mcp/src/tools.ts

import { Tool } from '@modelcontextprotocol/sdk/types.js';
import { searchMessages, readMessage, getProfile, listFolders, type Account } from './imap.js';
import { sendEmail, createDraft } from './smtp.js';

const ACCOUNT_PARAM = {
  account: {
    type: 'string',
    enum: ['yahoo', 'fetcherpay'],
    description: 'Which mailbox to use: "yahoo" (gheron01@yahoo.com) or "fetcherpay" (garfield.heron@fetcherpay.com). Defaults to "yahoo".',
  },
};

export const tools: Tool[] = [
  {
    name: 'get_profile',
    description: 'Get the email account profile (email address and name)',
    inputSchema: {
      type: 'object',
      properties: { ...ACCOUNT_PARAM },
    },
  },
  {
    name: 'search_messages',
    description: 'Search email messages by keyword, sender, or subject',
    inputSchema: {
      type: 'object',
      properties: {
        q: { type: 'string', description: 'Search query (keyword, from:email, subject:text)' },
        maxResults: { type: 'number', description: 'Max messages to return (default 20)' },
        ...ACCOUNT_PARAM,
      },
      required: ['q'],
    },
  },
  {
    name: 'read_message',
    description: 'Read a full email message by UID',
    inputSchema: {
      type: 'object',
      properties: {
        uid: { type: 'number', description: 'Message UID from search results' },
        ...ACCOUNT_PARAM,
      },
      required: ['uid'],
    },
  },
  {
    name: 'list_folders',
    description: 'List all email folders/mailboxes',
    inputSchema: {
      type: 'object',
      properties: { ...ACCOUNT_PARAM },
    },
  },
  {
    name: 'create_draft',
    description: 'Create a draft email',
    inputSchema: {
      type: 'object',
      properties: {
        to: { type: 'string', description: 'Recipient email address' },
        subject: { type: 'string', description: 'Email subject' },
        body: { type: 'string', description: 'Email body (plain text)' },
        ...ACCOUNT_PARAM,
      },
      required: ['to', 'subject', 'body'],
    },
  },
  {
    name: 'send_email',
    description: 'Send an email',
    inputSchema: {
      type: 'object',
      properties: {
        to: { type: 'string', description: 'Recipient email address' },
        subject: { type: 'string', description: 'Email subject' },
        body: { type: 'string', description: 'Email body (plain text)' },
        ...ACCOUNT_PARAM,
      },
      required: ['to', 'subject', 'body'],
    },
  },
];

function acct(args: Record<string, unknown>): Account {
  return (args.account as Account) ?? 'yahoo';
}

export async function handleToolCall(
  name: string,
  args: Record<string, unknown>
): Promise<{ content: Array<{ type: string; text: string }> }> {
  console.log(`[tool] ${name}`, JSON.stringify(args));
  const t0 = Date.now();
  try {
    let result: unknown;

    switch (name) {
      case 'get_profile':
        result = await getProfile(acct(args));
        break;

      case 'search_messages':
        result = await searchMessages(args.q as string, (args.maxResults as number) ?? 20, acct(args));
        break;

      case 'read_message':
        result = await readMessage(args.uid as number, acct(args));
        break;

      case 'list_folders':
        result = await listFolders(acct(args));
        break;

      case 'create_draft':
        result = await createDraft(args.to as string, args.subject as string, args.body as string, acct(args));
        break;

      case 'send_email':
        result = await sendEmail(args.to as string, args.subject as string, args.body as string, acct(args));
        break;

      // Legacy Yahoo-prefixed names — keep working for any cached Claude sessions
      case 'yahoo_get_profile':
        result = await getProfile('yahoo');
        break;
      case 'yahoo_search_messages':
        result = await searchMessages(args.q as string, (args.maxResults as number) ?? 20, 'yahoo');
        break;
      case 'yahoo_read_message':
        result = await readMessage(args.uid as number, 'yahoo');
        break;
      case 'yahoo_list_folders':
        result = await listFolders('yahoo');
        break;
      case 'yahoo_create_draft':
        result = await createDraft(args.to as string, args.subject as string, args.body as string, 'yahoo');
        break;
      case 'yahoo_send_email':
        result = await sendEmail(args.to as string, args.subject as string, args.body as string, 'yahoo');
        break;

      default:
        throw new Error(`Unknown tool: ${name}`);
    }

    console.log(`[tool] ${name} OK (${Date.now() - t0}ms)`);
    return {
      content: [{ type: 'text', text: JSON.stringify(result, null, 2) }],
    };
  } catch (error) {
    const msg = (error as Error).message;
    const stack = (error as Error).stack ?? '';
    console.error(`[tool] ${name} ERROR (${Date.now() - t0}ms):`, msg);
    console.error(stack);
    return {
      content: [{ type: 'text', text: `Error: ${msg}` }],
    };
  }
}