call-center-voice-agent-accelerator

Call Center Voice Agent Accelerator with Azure Voice Live API

| Open in GitHub Codespaces | Open in Dev Containers |—|—|

Welcome to the Call Center Real-time Voice Agent solution accelerator. It’s a lightweight template to create speech-to-speech voice agents that deliver personalized self-service experiences and natural-sounding voices, seamlessly integrated with telephony systems. This solution accelerator uses Azure Voice Live API and Azure Communication Services — Start locally, deploy later to Azure Web App. No PSTN number needed.

The Azure voice live API is a solution enabling low-latency, high-quality speech to speech interactions for voice agents. The API is designed for developers seeking scalable and efficient voice-driven experiences as it eliminates the need to manually orchestrate multiple components. By integrating speech recognition, generative AI, and text to speech functionalities into a single, unified interface, it provides an end-to-end solution for creating seamless experiences. Learn more about Azure Voice Live API.

The Azure Communication Services Calls Automation APIs provide telephony integration and real-time event triggers to perform actions based on custom business logic specific to their domain. Within the call automation APIs developers can use simple AI powered APIs, which can be used to play personalized greeting messages, recognize conversational voice inputs to gather information on contextual questions to drive a more self-service model with customers, use sentiment analysis to improve customer service overall. Learn more about Azure Communication Services (Call Automation).

Important Security Notice

This template, the application code and configuration it contains, has been built to showcase Microsoft Azure specific services and tools. We strongly advise our customers not to make this code part of their production environments without implementing or enabling additional security features. Learn more from Security for Azure AI Voice Live API.

Security Considerations

ACS currently does not support Managed Identity. The ACS connection string is stored securely in Key Vault and injected into the container app via its secret URL.


[**Features**](#features) \| [**Getting Started**](#getting-started) \| [**Testing the Agent**](#testing-the-agent) \| [**Guidance**](#guidance) \| [**Resources**](#resources)

Features

This sample demonstrates how to build a real-time voice agent using the Azure Speech Voice Live API.

The solution includes:

You can also try the Voice Live API via Azure AI Foundry for quick experimentation before deploying this template to your own Azure subscription.

Architecture diagram

|Architecture Diagram| |—|


Getting Started

| Open in GitHub Codespaces | Open in Dev Containers |—|—|

Prerequisites and Costs

To deploy this solution accelerator, ensure you have access to an Azure subscription with the necessary permissions to create resource groups and resources. Follow the steps in Azure Account Set Up.

Check the Azure Products by Region page and select a region where the following services are available: Azure AI Foundry Speech, Azure Communication Services, Azure Container Apps, and Container Registry.

Here are some example regions where the services are available: East US2, West US2, Southeast Asia, Central India, Sweden Central. Pricing varies per region and usage, so it isn’t possible to predict exact costs for your usage. The majority of the Azure resources used in this infrastructure are on usage-based pricing tiers. However, Azure Container Registry has a fixed cost per registry per day.

Use the Azure pricing calculator to calculate the cost of this solution in your subscription.

Product Description Cost
Azure Speech Voice Live Low-latency and high-quality speech to speech interactions Pricing
Azure Communication Services Server-based intelligent call workflows Pricing
Azure Container Apps Hosts the web application frontend Pricing
Azure Container Registry Stores container images for deployment Pricing

Here are some developers tools to set up as prerequisites:

Deployment Options

Pick from the options below to see step-by-step instructions for: GitHub Codespaces, VS Code Dev Containers, Local Environments, and Bicep deployments.

Deploy in GitHub Codespaces ### GitHub Codespaces You can run this solution using GitHub Codespaces. The button will open a web-based VS Code instance in your browser: 1. Open the solution accelerator (this may take several minutes): [![Open in GitHub Codespaces](https://github.com/codespaces/badge.svg)](https://codespaces.new/Azure-Samples/call-center-voice-agent-accelerator) 2. Accept the default values on the create Codespaces page. 3. Open a terminal window if it is not already open. 4. Follow the instructions in the helper script to populate deployment variables. 5. Continue with the [deploying steps](#deploying).
Deploy in VS Code Dev Containers ### VS Code Dev Containers You can run this solution in VS Code Dev Containers, which will open the project in your local VS Code using the [Dev Containers extension](https://marketplace.visualstudio.com/items?itemName=ms-vscode-remote.remote-containers): 1. Start Docker Desktop (install it, if not already installed) 2. Open the project: [![Open in Dev Containers](https://img.shields.io/static/v1?style=for-the-badge&label=Dev%20Containers&message=Open&color=blue&logo=visualstudiocode)](https://vscode.dev/redirect?url=vscode://ms-vscode-remote.remote-containers/cloneInVolume?url=https://vscode.dev/redirect?url=vscode://ms-vscode-remote.remote-containers/cloneInVolume?url=https://github.com/Azure-Samples/call-center-voice-agent-accelerator) 3. In the VS Code window that opens, once the project files show up (this may take several minutes), open a terminal window. 4. Follow the instructions in the helper script to populate deployment variables. 5. Continue with the [deploying steps](#deploying).
Deploy in your local environment ### Local environment If you're not using one of the above options for opening the project, then you'll need to: 1. Make sure the following tools are installed: * `bash` * [Azure Developer CLI (azd)](https://aka.ms/install-azd) 2. Download the project code: ```shell azd init -t Azure-Samples/call-center-voice-agent-accelerator/ ``` **Note:** the above command should be run in a new folder of your choosing. You do not need to run `git clone` to download the project source code. `azd init` handles this for you. 3. Open the project folder in your terminal or editor. 4. Continue with the [deploying steps](#deploying).

Deploying

Once you’ve opened the project in Codespaces or in Dev Containers or locally, you can deploy it to Azure following the following steps.

To change the azd parameters from the default values, follow the steps here.

  1. Login to Azure:

     azd auth login

  2. Provision and deploy all the resources:

     azd up

    It will prompt you to provide an azd environment name (like “flask-app”), select a subscription from your Azure account, and select a location (like “eastus”). Then it will provision the resources in your account and deploy the latest code. If you get an error with deployment, changing the location can help, as there may be availability constraints for some of the resources.

  3. When azd has finished deploying, you’ll see an endpoint URI in the command output. Visit that URI, and you should see the API output! 🎉

  4. When you’ve made any changes to the app code, you can just run:

     azd deploy

[!NOTE] AZD will also setup the local Python environment for you, using venv and installing the required packages.

[!NOTE]

Testing the Agent

After deployment, you can verify that your Voice Agent is running correctly using either the Web Client (for quick testing) or the ACS Phone Client (for simulating a real-world call center scenario).

🌐 Web Client (Test Mode)

Use this browser-based client to confirm your Container App is up and responding.

  1. Go to the Azure Portal and navigate to the Resource Group created by your deployment.
  2. Find and open the Container App resource.
  3. On the Overview page, copy the Application URL.
  4. Open the URL in your browser — a demo webpage should load.
  5. Click Start Talking to Agent to begin a voice session using your browser’s microphone and speaker.
  6. Click Stop Conversation to end the session.

⚠️ This web client is intended for testing purposes only. Use the ACS client below for production-like call flow testing.

📞 ACS Client (Call Center Scenario)

This simulates a real inbound phone call to your voice agent using Azure Communication Services (ACS).

1. Set Up Incoming Call Webhook

  1. In the same resource group, find and open the Communication Services resource.
  2. In the left-hand menu, click Events.

  3. Click + Event Subscription and fill in the following:

    • Event Type: IncomingCall
    • Endpoint Type: Web Hook
    • Endpoint Address: 
      https://<your-container-app-url>/acs/incomingcall

      Replace <your-container-app-url> with the Application URL from your Container App.

📸 Refer to the screenshot below for guidance:

Event Subscription screenshot

2. Get a Phone Number

If you haven’t already, obtain a phone number for your ACS resource:

👉 How to get a phone number (Microsoft Docs)

3. Call the Agent

Once your event subscription is configured and the phone number is active:

Local execution

Once the environment has been deployed with azd up you can also run the application locally.

Please follow the instructions in the instructions in service


Guidance

Responsible AI Transparency FAQ

Please refer to Transparency Note for responsible AI transparency details of the voice live api.

Resource Clean-up

When you no longer need the resources created in this article, run the following command to power down the app:

azd down

If you want to redeploy to a different region, delete the .azure directory before running azd up again. In a more advanced scenario, you could selectively edit files within the .azure directory to change the region.


Resources

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