Conversation Relay: Text-In, Text-Out Voice Bots in India

The routing update stores the relay URL and settings on the number and re-points its call handling at the relay. The relay test exchanges one turn with your bot before any caller does.

# Point a number at your relay bot
curl -X PATCH https://voice-api.edesy.in/v1/phone-numbers/$PHONE_NUMBER_ID/routing \
  -H "Authorization: Bearer $EDESY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "inbound_target_type": "relay",
    "inbound_relay_url": "wss://bot.example.com/relay",
    "inbound_relay_config": {
      "welcome_greeting": "Hi, thanks for calling Acme. How can I help?",
      "tts_language": "en-IN",
      "stt_language": "en-IN",
      "interruptible": true,
      "min_bargein_word_count": 1,
      "dtmf_detection": true,
      "custom_parameters": {"store": "pune"}
    }
  }'

# Preflight: one turn of conversation from Edesy's network, no call
curl -X POST https://voice-api.edesy.in/v1/relay-test \
  -H "Authorization: Bearer $EDESY_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"relay_url": "wss://bot.example.com/relay", "prompt": "what are your hours", "seconds": 5}'

Adapted from the conversation-relay-edesy sample: it receives text and sends text. Replace replyTo() with your LLM and it is a working phone bot.

// Minimal relay bot (Node.js, ws). Swap replyTo() for your LLM call.
const { WebSocketServer } = require('ws');
const wss = new WebSocketServer({ port: 8787, path: '/relay' });

wss.on('connection', (ws) => {
  const history = [];
  ws.on('message', (raw) => {
    const msg = JSON.parse(raw);
    switch (msg.type) {
      case 'setup':      // once per call: callSid, from, to, customParameters
        break;
      case 'prompt':     // the caller finished speaking
        history.push({ role: 'user', text: msg.voicePrompt });
        speak(ws, replyTo(msg.voicePrompt, history));
        break;
      case 'interrupt':  // trim the bot's last turn to what was heard
        if (history.at(-1)?.role === 'bot') history.at(-1).text = msg.utteranceUntilInterrupt;
        break;
      case 'dtmf':
        speak(ws, `You pressed ${msg.digit}.`);
        break;
    }
  });
});

function speak(ws, text) {
  const words = text.split(' ');
  words.forEach((w, i) => ws.send(JSON.stringify({
    type: 'text', token: i ? ` ${w}` : w,
    last: i === words.length - 1,   // flushes speech synthesis
  })));
}