npm install @latimer-woods-tech/telephony

wrangler secret put TELNYX_API_KEY
wrangler secret put DEEPGRAM_API_KEY
wrangler secret put ELEVENLABS_API_KEY

function transcribeAudio(
  audioBuffer: Uint8Array,
  env: { DEEPGRAM_API_KEY: string },
  opts?: { language?: string; model?: string },
): Promise<string>;

function synthesizeSpeech(
  text: string,
  env: { ELEVENLABS_API_KEY: string },
  opts?: { voiceId?: string; modelId?: string },
): Promise<Uint8Array>;

function verifyTelnyxWebhook(
  request: Request,
  secret: string,
): Promise<TelnyxEvent>;

class VoiceSession {
  constructor(config: VoiceSessionConfig);
  processAudio(audioBuffer: Uint8Array): Promise<Uint8Array>; // returns TTS audio
  getHistory(): LLMMessage[];
  end(): void;
}

interface VoiceSessionConfig {
  callId: string;
  direction: 'inbound' | 'outbound';
  voiceId: string;
  language?: string;
  systemPrompt: string;
  env: {
    TELNYX_API_KEY: string;
    DEEPGRAM_API_KEY: string;
    ELEVENLABS_API_KEY: string;
    ANTHROPIC_API_KEY: string;
    GROK_API_KEY: string;
    GROQ_API_KEY: string;
  };
}

import { VoiceSession, verifyTelnyxWebhook } from '@latimer-woods-tech/telephony';

app.post('/webhook/telnyx', async (c) => {
  const event = await verifyTelnyxWebhook(c.req.raw, c.env.TELNYX_API_KEY);

  if (event.data.event_type === 'call.answered') {
    const session = new VoiceSession({
      callId: event.data.payload.call_control_id,
      direction: 'inbound',
      voiceId: 'eleven-turbo-v2',
      systemPrompt: 'You are a friendly receptionist for Acme Corp.',
      env: c.env,
    });
    // Store session in Durable Object or KV by callId
  }

  return c.json({ received: true });
});