TwinMind Webhooks & Events

TwinMind Webhooks & Events

Overview

Implement webhook handlers for real-time TwinMind meeting events and notifications.

Prerequisites

• TwinMind Pro/​Enterprise account
• Public HTTPS endpoint for webhooks
• Webhook secret configured
• Understanding of event-driven architecture

Instructions

Step 1: Define Event Types

// src/​twinmind/​events/​types.ts
export enum TwinMindEventType {
  // Transcription events
  TRANSCRIPTION_STARTED = 'transcription.started',
  TRANSCRIPTION_COMPLETED = 'transcription.completed',
  TRANSCRIPTION_FAILED = 'transcription.failed',

  // Meeting events
  MEETING_STARTED = 'meeting.started',
  MEETING_ENDED = 'meeting.ended',
  MEETING_PARTICIPANT_JOINED = 'meeting.participant.joined',
  MEETING_PARTICIPANT_LEFT = 'meeting.participant.left',

  // Summary events
  SUMMARY_GENERATED = 'summary.generated',
  ACTION_ITEMS_EXTRACTED = 'action_items.extracted',

  // Calendar events
  CALENDAR_SYNCED = 'calendar.synced',
  CALENDAR_EVENT_REMINDER = 'calendar.event.reminder',

  // Account events
  USAGE_LIMIT_WARNING = 'usage.limit.warning',
  USAGE_LIMIT_EXCEEDED = 'usage.limit.exceeded',
}

export interface TwinMindEvent<T = any> {
  id: string;
  type: TwinMindEventType;
  created_at: string;
  data: T;
}

export interface TranscriptionCompletedData {
  transcript_id: string;
  duration_seconds: number;
  language: string;
  word_count: number;
  speaker_count: number;
  model: string;
}

export interface MeetingEndedData {
  meeting_id: string;
  transcript_id: string;
  title: string;
  duration_seconds: number;
  participants: string[];
  summary_available: boolean;
}

export interface SummaryGeneratedData {
  summary_id: string;
  transcript_id: string;
  action_item_count: number;
  key_point_count: number;
}

export interface ActionItemsExtractedData {
  transcript_id: string;
  action_items: Array<{
    text: string;
    assignee?: string;
    due_date?: string;
  }>;
}

Step 2: Implement Webhook Handler

// src/​twinmind/​webhooks/​handler.ts
import crypto from 'crypto';
import express, { Request, Response, NextFunction } from 'express';
import { TwinMindEvent, TwinMindEventType } from '../​events/​types';

// Signature verification middleware
export function verifySignature(
  req: Request,
  res: Response,
  next: NextFunction
): void {
  const signature = req.headers['x-twinmind-signature'] as string;
  const timestamp = req.headers['x-twinmind-timestamp'] as string;
  const secret = process.env.TWINMIND_WEBHOOK_SECRET!;

  if (!signature || !timestamp) {
    res.status(401).json({ error: 'Missing signature or timestamp' });
    return;
  }

  // Check timestamp to prevent replay attacks (5 minute window)
  const timestampMs = parseInt(timestamp) * 1000;
  const now = Date.now();
  if (Math.abs(now - timestampMs) > 5 * 60 * 1000) {
    res.status(401).json({ error: 'Request too old' });
    return;
  }

  // Verify signature
  const payload = `${timestamp}.${JSON.stringify(req.body)}`;
  const expectedSignature = crypto
    .createHmac('sha256', secret)
    .update(payload)
    .digest('hex');

  if (!crypto.timingSafeEqual(
    Buffer.from(signature),
    Buffer.from(`sha256=${expectedSignature}`)
  )) {
    res.status(401).json({ error: 'Invalid signature' });
    return;
  }

  next();
}

// Event handlers registry
type EventHandler<T = any> = (event: TwinMindEvent<T>) => Promise<void>;

const handlers = new Map<TwinMindEventType, EventHandler[]>();

export function registerHandler<T>(
  eventType: TwinMindEventType,
  handler: EventHandler<T>
): void {
  const existing = handlers.get(eventType) || [];
  existing.push(handler);
  handlers.set(eventType, existing);
}

// Main webhook route handler
export async function handleWebhook(
  req: Request,
  res: Response
): Promise<void> {
  const event = req.body as TwinMindEvent;

  console.log(`Received event: ${event.type} (${event.id})`);

  // Acknowledge receipt immediately
  res.status(200).json({ received: true, event_id: event.id });

  // Process event asynchronously
  try {
    const eventHandlers = handlers.get(event.type as TwinMindEventType);

    if (eventHandlers && eventHandlers.length > 0) {
      await Promise.all(
        eventHandlers.map(handler => handler(event))
      );
    } else {
      console.log(`No handlers registered for event type: ${event.type}`);
    }
  } catch (error) {
    console.error(`Error processing event ${event.id}:`, error);
    // Don't throw - we already acknowledged receipt
  }
}

Step 3: Implement Event Handlers

// src/​twinmind/​webhooks/​event-handlers.ts
import {
  TwinMindEvent,
  TwinMindEventType,
  TranscriptionCompletedData,
  MeetingEndedData,
  SummaryGeneratedData,
  ActionItemsExtractedData,
} from '../​events/​types';
import { registerHandler } from './​handler';
import { notifySlack, sendEmail } from '../​notifications';
import { createTasksInLinear } from '../​integrations/​linear';

// Handle transcription completed
registerHandler<TranscriptionCompletedData>(
  TwinMindEventType.TRANSCRIPTION_COMPLETED,
  async (event) => {
    const { transcript_id, duration_seconds, word_count, speaker_count } = event.data;

    console.log(`Transcription completed: ${transcript_id}`);
    console.log(`  Duration: ${duration_seconds}s`);
    console.log(`  Words: ${word_count}`);
    console.log(`  Speakers: ${speaker_count}`);

    // Trigger summary generation
    const client = getTwinMindClient();
    await client.post('/​summarize', { transcript_id });
  }
);

// Handle meeting ended
registerHandler<MeetingEndedData>(
  TwinMindEventType.MEETING_ENDED,
  async (event) => {
    const { meeting_id, title, duration_seconds, participants, summary_available } = event.data;

    console.log(`Meeting ended: ${title} (${meeting_id})`);

    // Notify participants
    await notifySlack({
      channel: '#meetings',
      message: `Meeting "${title}" has ended (${Math.round(duration_seconds / 60)} minutes)`,
      participants,
    });

    // If summary is ready, send it
    if (summary_available) {
      const client = getTwinMindClient();
      const summary = await client.get(`/​summaries/​${event.data.transcript_id}`);

      await sendEmail({
        to: participants,
        subject: `Meeting Summary: ${title}`,
        body: summary.data.summary,
      });
    }
  }
);

// Handle summary generated
registerHandler<SummaryGeneratedData>(
  TwinMindEventType.SUMMARY_GENERATED,
  async (event) => {
    const { summary_id, transcript_id, action_item_count } = event.data;

    console.log(`Summary generated: ${summary_id}`);
    console.log(`  Action items: ${action_item_count}`);

    // Store summary in database
    await db.summaries.create({
      id: summary_id,
      transcript_id,
      created_at: new Date(event.created_at),
    });
  }
);

// Handle action items extracted
registerHandler<ActionItemsExtractedData>(
  TwinMindEventType.ACTION_ITEMS_EXTRACTED,
  async (event) => {
    const { transcript_id, action_items } = event.data;

    console.log(`Action items extracted: ${action_items.length}`);

    // Create tasks in project management tool
    if (action_items.length > 0) {
      await createTasksInLinear(action_items);
    }
  }
);

// Handle usage warning
registerHandler(
  TwinMindEventType.USAGE_LIMIT_WARNING,
  async (event) => {
    console.warn('Usage limit warning:', event.data);

    await notifySlack({
      channel: '#alerts',
      message: `:warning: TwinMind usage at ${event.data.percent_used}% of limit`,
    });
  }
);

Step 4: Set Up Webhook Endpoint

// src/​api/​webhooks/​twinmind.ts
import express from 'express';
import { verifySignature, handleWebhook } from '../​../​twinmind/​webhooks/​handler';

const router = express.Router();

// Raw body parser for signature verification
router.use(express.json({
  verify: (req: any, res, buf) => {
    req.rawBody = buf;
  }
}));

// Webhook endpoint
router.post(
  '/​twinmind',
  verifySignature,
  handleWebhook
);

export default router;

Step 5: Register Webhooks

// scripts/​register-webhooks.ts
import { getTwinMindClient } from '../​src/​twinmind/​client';
import { TwinMindEventType } from '../​src/​twinmind/​events/​types';

async function registerWebhooks() {
  const client = getTwinMindClient();

  const webhookUrl = process.env.WEBHOOK_BASE_URL + '/​webhooks/​twinmind';

  // Register webhook
  const response = await client.post('/​webhooks', {
    url: webhookUrl,
    events: [
      TwinMindEventType.TRANSCRIPTION_COMPLETED,
      TwinMindEventType.MEETING_ENDED,
      TwinMindEventType.SUMMARY_GENERATED,
      TwinMindEventType.ACTION_ITEMS_EXTRACTED,
      TwinMindEventType.USAGE_LIMIT_WARNING,
    ],
    enabled: true,
  });

  console.log('Webhook registered:', response.data);

  // Generate and store webhook secret
  console.log('Webhook Secret:', response.data.secret);
  console.log('Add to .env: TWINMIND_WEBHOOK_SECRET=' + response.data.secret);
}

registerWebhooks();

Step 6: Implement Retry Logic for Failed Events

// src/​twinmind/​webhooks/​retry.ts
import { TwinMindEvent } from '../​events/​types';

interface FailedEvent {
  event: TwinMindEvent;
  attempts: number;
  lastError: string;
  nextRetry: Date;
}

class WebhookRetryQueue {
  private queue: FailedEvent[] = [];
  private maxRetries = 5;
  private baseDelayMs = 60000; // 1 minute

  async add(event: TwinMindEvent, error: Error): Promise<void> {
    const existing = this.queue.find(f => f.event.id === event.id);

    if (existing) {
      existing.attempts += 1;
      existing.lastError = error.message;
      existing.nextRetry = new Date(
        Date.now() + this.baseDelayMs * Math.pow(2, existing.attempts)
      );

      if (existing.attempts >= this.maxRetries) {
        // Move to dead letter queue
        await this.moveToDeadLetter(existing);
        this.queue = this.queue.filter(f => f.event.id !== event.id);
      }
    } else {
      this.queue.push({
        event,
        attempts: 1,
        lastError: error.message,
        nextRetry: new Date(Date.now() + this.baseDelayMs),
      });
    }
  }

  async processRetries(): Promise<void> {
    const now = new Date();
    const readyEvents = this.queue.filter(f => f.nextRetry <= now);

    for (const failedEvent of readyEvents) {
      try {
        await this.reprocessEvent(failedEvent.event);
        this.queue = this.queue.filter(f => f.event.id !== failedEvent.event.id);
        console.log(`Successfully reprocessed event: ${failedEvent.event.id}`);
      } catch (error: any) {
        await this.add(failedEvent.event, error);
      }
    }
  }

  private async reprocessEvent(event: TwinMindEvent): Promise<void> {
    // Re-dispatch to handlers
    const handlers = getHandlersForEvent(event.type);
    await Promise.all(handlers.map(h => h(event)));
  }

  private async moveToDeadLetter(failedEvent: FailedEvent): Promise<void> {
    console.error(`Event ${failedEvent.event.id} moved to dead letter queue after ${failedEvent.attempts} attempts`);

    // Store in database for manual review
    await db.deadLetterQueue.create({
      event_id: failedEvent.event.id,
      event_type: failedEvent.event.type,
      payload: failedEvent.event,
      attempts: failedEvent.attempts,
      last_error: failedEvent.lastError,
    });

    // Alert ops team
    await notifySlack({
      channel: '#alerts',
      message: `:x: Webhook event failed after ${failedEvent.attempts} attempts: ${failedEvent.event.id}`,
    });
  }
}

export const retryQueue = new WebhookRetryQueue();

// Start retry processor
setInterval(() => retryQueue.processRetries(), 60000);

Output

• Event type definitions
• Webhook handler with signature verification
• Event processing logic
• Webhook registration script
• Retry queue for failed events

Webhook Events Reference

Error Handling

Resources

• TwinMind Webhooks API
• Webhook Best Practices
• Event Reference

Next Steps

For performance optimization, see twinmind-performance-tuning.