index.js

import RingCentral from '@ringcentral/sdk'
import Subscriptions from '@ringcentral/subscriptions'
import Speaker from 'speaker'
import { nonstandard } from 'wrtc'
import Softphone from 'ringcentral-softphone'
import fs from 'fs'

const rc = new RingCentral({
  server: process.env.RINGCENTRAL_SERVER_URL,
  clientId: process.env.RINGCENTRAL_CLIENT_ID,
  clientSecret: process.env.RINGCENTRAL_CLIENT_SECRET
})

;(async () => {
  await rc.login({
    username: process.env.RINGCENTRAL_USERNAME,
    extension: process.env.RINGCENTRAL_EXTENSION,
    password: process.env.RINGCENTRAL_PASSWORD
  })
  const softphone = new Softphone(rc)
  await softphone.register()

  softphone.on('INVITE', sipMessage => {
    softphone.answer(sipMessage)
    softphone.once('track', e => {
      const audioSink = new nonstandard.RTCAudioSink(e.track)
      let speaker = null
      let prevSampleRate = null
      const audioFilePath = 'call.raw'
      if (fs.existsSync(audioFilePath)) {
        fs.unlinkSync(audioFilePath)
      }
      const writeStream = fs.createWriteStream(audioFilePath, { flags: 'a' })
      audioSink.ondata = data => {
        console.log('live audio data receivedlive audio data received, sample rate is', data.sampleRate)
        if (speaker === null) {
          if (data.sampleRate === prevSampleRate) { // wait until sample rate stable
            speaker = new Speaker({ channels: data.channelCount, bitDepth: data.bitsPerSample, sampleRate: data.sampleRate, signed: true })
          }
          prevSampleRate = data.sampleRate
        } else {
          speaker.write(Buffer.from(data.samples.buffer))
          writeStream.write(Buffer.from(data.samples.buffer))
        }
      }
      softphone.once('BYE', () => {
        audioSink.stop()
        speaker.close()
      })
    })
  })

  const r = await rc.get('/restapi/v1.0/account/~/extension')
  const json = await r.json()
  const agentExt = json.records.filter(ext => ext.extensionNumber === process.env.RINGCENTRAL_AGENT_EXT)[0]
  const subscriptions = new Subscriptions({
    sdk: rc
  })
  const subscription = subscriptions.createSubscription({
    pollInterval: 10 * 1000,
    renewHandicapMs: 2 * 60 * 1000
  })
  subscription.setEventFilters([`/restapi/v1.0/account/~/extension/${agentExt.id}/telephony/sessions`])
  subscription.on(subscription.events.notification, async function (message) {
    if (message.body.parties.some(p => p.status.code === 'Answered' && p.direction === 'Inbound')) {
      await rc.post(`/restapi/v1.0/account/~/telephony/sessions/${message.body.telephonySessionId}/supervise`, {
        mode: 'Listen',
        supervisorDeviceId: softphone.device.id,
        agentExtensionNumber: agentExt.extensionNumber
      })
    }
  })
  await subscription.register()
})()