Issue with web call recording

Question

Issue with web call recording

Vishal Maurya 0

How we can record a call do we need backend for that ? . can you please provide the code for frontend and backend?

Bhargavi Naragani 6,535 Microsoft External Staff Moderator

If you're using Azure Communication Services (ACS), which is Microsoft’s native way to build web calling/chat experiences, so yes you do need backend support to initiate and control the recording securely and reliably. This is by design, to protect user privacy and ensure that only authorized servers trigger recordings.

Backend Code (Node.js Example):

const { CallAutomationClient } = require("@azure/communication-call-automation");
const connectionString = process.env.ACS_CONNECTION_STRING;
const client = new CallAutomationClient(connectionString);
// Start recording
async function startRecording(serverCallId, callbackUrl, containerUrl) {
  const options = {
    callLocator: { kind: "serverCallLocator", id: serverCallId },
    recordingChannel: "Mixed",            // or 'Unmixed'
    recordingContent: "AudioVideo",
    recordingFormat: "Mp4",
    recordingStateCallbackUri: callbackUrl,
    recordingStorage: {
      recordingStorageKind: "azureBlobStorage",
      recordingDestinationContainerUrl: containerUrl
    }
  };
  return await client.getCallRecording().start(options);
}
// Stop recording
async function stopRecording(recordingId) {
  return await client.getCallRecording().stop(recordingId);
}

Use serverCallId from your call setup (via Call Automation or Calling Client SDK)
Use Azure Blob Storage to save finalized recordings.

Frontend (JavaScript SDK) - To detect and control recording from client side (preview feature):

import { CallClient, AzureCommunicationTokenCredential } from "@azure/communication-calling";
const callClient = new CallClient();
const token = new AzureCommunicationTokenCredential(userToken);
const callAgent = await callClient.createCallAgent(token, { displayName: "Alice" });
const call = await callAgent.join(...);
// monitor recording status
const recordingApi = call.feature(Features.Recording);
recordingApi.on('isRecordingActiveChanged', () => {
  console.log("Recording active:", recordingApi.isRecordingActive);
});

You still need your backend to trigger recording; this only provides UI updates.

Kindly refer to the below documentations for better understanding:
Call Recording Overview
Call Recording QuickStart
Call Automation Overview
Start Recording REST API
Client‑side Recording Management

Hope this helps, if you have any further concerns or queries, please feel free to reach out to us.

2 answers

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Answer 1

Vishal Maurya 0

do we need to do any setup on azure? and how can I get the serverCallId, callbackUrl and containerUrl ? and by using this we can any kind of call like room call, simple call,

Bhargavi Naragani 6,535 Reputation points Microsoft External Staff Moderator

2025-07-09T08:34:18.7033333+00:00

Hi Vishal Maurya,
We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution please do share that same with the community as it can be helpful to others. Otherwise, will respond with more details and we will try to help.

Answer 2

Hi Vishal Maurya,

Yes, there are 3 main setup steps you'll need to complete in your Azure environment:

Create an Azure Communication Services (ACS) Resource, this is the core service for enabling voice/video calls and recording. Go to the Azure Portal: https://portal.azure.com, Search for “Communication Services”. Click Create, give it a name and region. Once created, you'll get a Connection String, this is used in your backend code Create ACS Resource
Set Up Azure Blob Storage (for storing recordings), Recordings are securely stored in Azure Blob. Here's how: Go to the Azure Portal => Storage accounts - Create a new storage account - inside it, create a Container (e.g., recordings) Enable public access = private (secure), generate a Shared Access Signature (SAS) for your container, this becomes your containerUrl. Grant access using SAS
Create a Backend API or Azure Function for Recording - This backend is responsible for securely triggering startRecording() and managing tokens.

Get the Required Parameters:

Parameter	How to Get It
`serverCallId`	After a call is created or joined via Call Automation, the server returns a `serverCallId`. You’ll find this in the response of `createCall()`or `joinCall()`.
`callbackUrl`	This is a URL to your publicly accessible endpoint (API/Function App) that receives recording status updates. You can use Azure Function with HTTP trigger.
`containerUrl`	This is the SAS URL of your Azure Blob Storage container where recordings will be stored.

Sample Flow with Call Automation

// Backend example: Join Call and Get serverCallId
const callConnection = await callAutomationClient.createCall({
  source: { phoneNumber: "<ACS phone>" },
  targets: [{ phoneNumber: "<User phone>" }],
  callbackUri: "<Your webhook callback URL>"
});
const serverCallId = callConnection.properties.callConnectionId;

Call Automation - Create/Join Calls

by using this we can any kind of call like room call, simple call?

Yes, using Azure Communication Services (ACS) Call Recording, you can record both types of calls

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Issue with web call recording

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