Call Center AI

AI-powered call center solution with Azure and OpenAI GPT.

Overview

Send a phone call from AI agent, in an API call. Or, directly call the bot from the configured phone number!

Insurance, IT support, customer service, and more. The bot can be customized in few seconds (really) to fit your needs.

# Ask the bot to call a phone number
data='{
  "bot_company": "Contoso",
  "bot_name": "Amélie",
  "phone_number": "+11234567890",
  "task": "Help the customer with their digital workplace. Assistant is working for the IT support department. The objective is to help the customer with their issue and gather information in the claim.",
  "agent_phone_number": "+33612345678",
  "claim": [
    {
      "name": "hardware_info",
      "type": "text"
    },
    {
      "name": "first_seen",
      "type": "datetime"
    },
    {
      "name": "building_location",
      "type": "text"
    }
  ]
}'

curl \
  --header 'Content-Type: application/json' \
  --request POST \
  --url https://xxx/call \
  --data $data

Features

Note

This project is a proof of concept. It is not intended to be used in production. This demonstrates how can be combined Azure Communication Services, Azure Cognitive Services and Azure OpenAI to build an automated call center solution.

• Access the claim on a public website
• Access to customer conversation history
• Allow user to change the language of the conversation
• Assistant can send SMS to the user for futher information
• Bot can be called from a phone number
• Bot use multiple voice tones (e.g. happy, sad, neutral) to keep the conversation engaging
• Company products (= lexicon) can be understood by the bot (e.g. a name of a specific insurance product)
• Create by itself a todo list of tasks to complete the claim
• Customizable prompts
• Disengaging from a human agent when needed
• Filter out inappropriate content from the LLM, like profanity or concurrence company names
• Fine understanding of the customer request with GPT-4o and GPT 4o-mini
• Follow a specific data schema for the claim
• Has access to a documentation database (few-shot training / RAG)
• Help the user to find the information needed to complete the claim
• Jailbreak detection
• Lower AI Search cost by usign a Redis cache
• Monitoring and tracing with Application Insights
• Perform user tests with feature flags
• Receive SMS during a conversation for explicit wordings
• Record the calls for audit and quality assurance
• Responses are streamed from the LLM to the user, to avoid long pauses
• Send a SMS report after the call
• Take back a conversation after a disengagement
• Call back the user when needed
• Simulate a IVR workflow

Demo

A French demo is avaialble on YouTube. Do not hesitate to watch the demo in x1.5 speed to get a quick overview of the project.

Main interactions shown in the demo:

1. User calls the call center
2. The bot answers and the conversation starts
3. The bot stores conversation, claim and todo list in the database

Extract of the data stored during the call:

{
  "claim": {
    "incident_datetime": "2024-10-08T02:00:00",
    "incident_description": "La trottinette électrique fait des bruits bizarres et émet de la fumée blanche.",
    "incident_location": "46 rue du Charles de Gaulle",
    "injuries": "Douleur au genou suite à une chute.",
    "involved_parties": "Lesne",
    "policy_number": "B02131325XPGOLMP"
  },
  "messages": [
    {
      "created_at": "2024-10-08T11:23:41.824758Z",
      "action": "call",
      "content": "",
      "persona": "human",
      "style": "none",
      "tool_calls": []
    },
    {
      "created_at": "2024-10-08T11:23:55.421654Z",
      "action": "talk",
      "content": "Bonjour, je m'appelle Amélie, de Contoso Assurance ! Comment puis-je vous aider aujourd'hui ?",
      "persona": "assistant",
      "style": "cheerful",
      "tool_calls": []
    },
    {
      "created_at": "2024-10-08T11:24:19.972737Z",
      "action": "talk",
      "content": "Oui bien sûr. Bonjour, je vous appelle parce que j'ai un problème avec ma trottinette électrique. Elle marche plus depuis ce matin, elle fait des bruits bizarres et il y a une fumée blanche qui sort de la trottinette.",
      "persona": "human",
      "style": "none",
      "tool_calls": []
    }
  ],
  "next": {
    "action": "case_closed",
    "justification": "The customer provided all necessary information for the claim, and they expressed satisfaction with the assistance received. No further action is required at this time."
  },
  "synthesis": {
    "long": "You reported an issue with your electric scooter, which started making strange noises and emitting white smoke. This incident occurred at 2:00 AM while you were riding it, leading to a fall and resulting in knee pain. The location of the incident was noted, and your policy details were confirmed. I have documented all the necessary information to file your claim. Please take care of your knee, and feel free to reach out if you need further assistance.",
    "satisfaction": "high",
    "short": "the breakdown of your scooter",
    "improvement_suggestions": "Ensure that the assistant provides clear next steps and offers to schedule follow-up calls proactively to enhance customer support."
  },
  ...
}

User report after the call

A report is available at https://[your_domain]/report/[phone_number] (like http://localhost:8080/report/%2B133658471534). It shows the conversation history, claim data and reminders.

High level architecture

---
title: System diagram (C4 model)
---
graph
  user(["User"])
  agent(["Agent"])

  app["Call Center AI"]

  app -- Transfer to --> agent
  app -. Send voice .-> user
  user -- Call --> app

Loading

Component level architecture

---
title: Claim AI component diagram (C4 model)
---
graph LR
  agent(["Agent"])
  user(["User"])

  subgraph "Claim AI"
    ada["Embedding<br>(ADA)"]
    app["App<br>(Container App)"]
    communication_services["Call & SMS gateway<br>(Communication Services)"]
    db[("Conversations and claims<br>(Cosmos DB / SQLite)")]
    eventgrid["Broker<br>(Event Grid)"]
    gpt["LLM<br>(GPT-4o)"]
    queues[("Queues<br>(Azure Storage)")]
    redis[("Cache<br>(Redis)")]
    search[("RAG<br>(AI Search)")]
    sounds[("Sounds<br>(Azure Storage)")]
    sst["Speech-to-Text<br>(Cognitive Services)"]
    translation["Translation<br>(Cognitive Services)"]
    tts["Text-to-Speech<br>(Cognitive Services)"]
  end

  app -- Respond with text --> communication_services
  app -- Ask for translation --> translation
  app -- Ask to transfer --> communication_services
  app -- Few-shot training --> search
  app -- Generate completion --> gpt
  app -- Get cached data --> redis
  app -- Save conversation --> db
  app -- Send SMS report --> communication_services
  app -. Watch .-> queues

  communication_services -- Generate voice --> tts
  communication_services -- Load sound --> sounds
  communication_services -- Notifies --> eventgrid
  communication_services -- Send SMS --> user
  communication_services -- Transfer to --> agent
  communication_services -- Transform voice --> sst
  communication_services -. Send voice .-> user

  eventgrid -- Push to --> queues

  search -- Generate embeddings --> ada

  user -- Call --> communication_services

Loading

Sequence diagram

sequenceDiagram
    autonumber

    actor Customer
    participant PSTN
    participant Text to Speech
    participant Speech to Text
    actor Human agent
    participant Event Grid
    participant Communication Services
    participant App
    participant Cosmos DB
    participant OpenAI GPT
    participant AI Search

    App->>Event Grid: Subscribe to events
    Customer->>PSTN: Initiate a call
    PSTN->>Communication Services: Forward call
    Communication Services->>Event Grid: New call event
    Event Grid->>App: Send event to event URL (HTTP webhook)
    activate App
    App->>Communication Services: Accept the call and give inbound URL
    deactivate App
    Communication Services->>Speech to Text: Transform speech to text

    Communication Services->>App: Send text to the inbound URL
    activate App
    alt First call
        App->>Communication Services: Send static SSML text
    else Callback
        App->>AI Search: Gather training data
        App->>OpenAI GPT: Ask for a completion
        OpenAI GPT-->>App: Respond (HTTP/2 SSE)
        loop Over buffer
            loop Over multiple tools
                alt Is this a claim data update?
                    App->>Cosmos DB: Update claim data
                else Does the user want the human agent?
                    App->>Communication Services: Send static SSML text
                    App->>Communication Services: Transfer to a human
                    Communication Services->>Human agent: Call the phone number
                else Should we end the call?
                    App->>Communication Services: Send static SSML text
                    App->>Communication Services: End the call
                end
            end
        end
        App->>Cosmos DB: Persist conversation
    end
    deactivate App
    Communication Services->>PSTN: Send voice
    PSTN->>Customer: Forward voice

Loading

Deployment

Prerequisites

Prefer using GitHub Codespaces for a quick start. The environment will setup automatically with all the required tools.

In macOS, with Homebrew, simply type make brew.

For other systems, make sure you have the following installed:

• Bash compatible shell, like bash or zsh
• yq
• Make, apt install make (Ubuntu), yum install make (CentOS), brew install make (macOS)
• Azure CLI
• Azure Functions Core Tools
• Twilio CLI (optional)

Then, Azure resources are needed:

1. Create a new resource group

• Prefer to use lowercase and no special characters other than dashes (e.g. ccai-customer-a)

2. Create a Communication Services resource

• Same name as the resource group
• Enable system managed identity

3. Buy a phone number

• From the Communication Services resource
• Allow inbound and outbound communication
• Enable voice (required) and SMS (optional) capabilities

Now that the prerequisites are configured (local + Azure), the deployment can be done.

Remote (on Azure)

A pre-built container image is available on GitHub Actions, it will be used to deploy the solution on Azure:

• Latest version from a branch: ghcr.io/clemlesne/call-center-ai:main
• Specific tag: ghcr.io/clemlesne/call-center-ai:0.1.0 (recommended)

1. Create the light config file

Local config file is named config.yaml. It will be used by install scripts (incl. Makefile and Bicep) to configure the Azure resources.

Fill the file with the following content (must be customized for your need):

# config.yaml
conversation:
  initiate:
    # Phone number the bot will transfer the call to if customer asks for a human agent
    agent_phone_number: "+33612345678"
    bot_company: Contoso
    bot_name: Amélie
    lang: {}

communication_services:
  # Phone number purshased from Communication Services
  phone_number: "+33612345678"

sms: {}

prompts:
  llm: {}
  tts: {}

2. Connect to your Azure environment

az login

3. Run deployment automation

make deploy name=my-rg-name

• Wait for the deployment to finish

4. Get the logs

make logs name=my-rg-name

Local (on your machine)

1. Create the full config file

Tip

To use a Service Principal to authenticate to Azure, you can also add the following in a .env file:

AZURE_CLIENT_ID=xxx
AZURE_CLIENT_SECRET=xxx
AZURE_TENANT_ID=xxx

Tip

If the application is already deployed on Azure, you can run make name=my-rg-name sync-local-config to copy the configuration from the Azure Function App to your local machine.

Local config file is named config.yaml:

# config.yaml
resources:
  public_url: https://xxx.blob.core.windows.net/public

conversation:
  initiate:
    agent_phone_number: "+33612345678"
    bot_company: Contoso
    bot_name: Robert

communication_services:
  access_key: xxx
  call_queue_name: call-33612345678
  endpoint: https://xxx.france.communication.azure.com
  phone_number: "+33612345678"
  post_queue_name: post-33612345678
  recording_container_url: https://xxx.blob.core.windows.net/recordings
  resource_id: xxx
  sms_queue_name: sms-33612345678

cognitive_service:
  # Must be of type "AI services multi-service account"
  endpoint: https://xxx.cognitiveservices.azure.com

llm:
  fast:
    mode: azure_openai
    azure_openai:
      context: 16385
      deployment: gpt-4o-mini-2024-07-18
      endpoint: https://xxx.openai.azure.com
      model: gpt-4o-mini
      streaming: true
  slow:
    mode: azure_openai
    azure_openai:
      context: 128000
      deployment: gpt-4o-2024-08-06
      endpoint: https://xxx.openai.azure.com
      model: gpt-4o
      streaming: true

ai_search:
  embedding_deployment: text-embedding-3-large-1
  embedding_dimensions: 3072
  embedding_endpoint: https://xxx.openai.azure.com
  embedding_model: text-embedding-3-large
  endpoint: https://xxx.search.windows.net
  index: trainings

ai_translation:
  access_key: xxx
  endpoint: https://xxx.cognitiveservices.azure.com

2. Run the deployment automation

make deploy-bicep deploy-post name=my-rg-name

• This will deploy the Azure resources without the API server, allowing you to test the bot locally
• Wait for the deployment to finish

3. Initialize local function config

Copy local.example.settings.json to local.settings.json, then fill the required fields:

• APPLICATIONINSIGHTS_CONNECTION_STRING, as the connection string of the Application Insights resource
• AzureWebJobsStorage, as the connection string of the Azure Storage account

4. Connect to Azure Dev tunnels

Important

Tunnel requires to be run in a separate terminal, because it needs to be running all the time

# Log in once
devtunnel login

# Start the tunnel
make tunnel

5. Iterate quickly with the code

Note

To override a specific configuration value, you can use environment variables. For example, to override the llm.fast.endpoint value, you can use the LLM__FAST__ENDPOINT variable:

LLM__FAST__ENDPOINT=https://xxx.openai.azure.com

Note

Also, local.py script is available to test the application without the need of a phone call (= without Communication Services). Run the script with:

python3 -m tests.local

make dev

• Code is automatically reloaded on file changes, no need to restart the server
• The API server is available at http://localhost:8080

Advanced usage

Enable call recording

Call recording is disabled by default. To enable it:

1. Create a new container in the Azure Storage account (i.e. recordings), it is already done if you deployed the solution on Azure
2. Update the feature flag recording_enabled in App Configuration to true

Add my custom training data with AI Search

Training data is stored on AI Search to be retrieved by the bot, on demand.

Required index schema:

Field Name	Type	Retrievable	Searchable	Dimensions	Vectorizer
answer	Edm.String	Yes	Yes
context	Edm.String	Yes	Yes
created_at	Edm.String	Yes	No
document_synthesis	Edm.String	Yes	Yes
file_path	Edm.String	Yes	No
id	Edm.String	Yes	No
question	Edm.String	Yes	Yes
vectors	Collection(Edm.Single)	No	Yes	1536	OpenAI ADA

Software to fill the index is included on Synthetic RAG Index repository.

Customize the languages

The bot can be used in multiple languages. It can understand the language the user chose.

See the list of supported languages for the Text-to-Speech service.

# config.yaml
conversation:
  initiate:
    lang:
      default_short_code: fr-FR
      availables:
        - pronunciations_en: ["French", "FR", "France"]
          short_code: fr-FR
          voice: fr-FR-DeniseNeural
        - pronunciations_en: ["Chinese", "ZH", "China"]
          short_code: zh-CN
          voice: zh-CN-XiaoqiuNeural

If you built and deployed an Azure Speech Custom Neural Voice (CNV), add field custom_voice_endpoint_id on the language configuration:

# config.yaml
conversation:
  initiate:
    lang:
      default_short_code: fr-FR
      availables:
        - pronunciations_en: ["French", "FR", "France"]
          short_code: fr-FR
          voice: xxx
          custom_voice_endpoint_id: xxx

Customize the moderation levels

Levels are defined for each category of Content Safety. The higher the score, the more strict the moderation is, from 0 to 7. Moderation is applied on all bot data, including the web page and the conversation. Configure them in Azure OpenAI Content Filters.

Customize the claim data schema

Customization of the data schema is fully supported. You can add or remove fields as needed, depending on the requirements.

By default, the schema of composed of:

• caller_email (email)
• caller_name (text)
• caller_phone (phone_number)

Values are validated to ensure the data format commit to your schema. They can be either:

• datetime
• email
• phone_number (E164 format)
• text

Finally, an optional description can be provided. The description must be short and meaningful, it will be passed to the LLM.

Default schema, for inbound calls, is defined in the configuration:

# config.yaml
conversation:
  default_initiate:
    claim:
      - name: additional_notes
        type: text
        # description: xxx
      - name: device_info
        type: text
        # description: xxx
      - name: incident_datetime
        type: datetime
        # description: xxx

Claim schema can be customized for each call, by adding the claim field in the POST /call API call.

Customize the call objective

The objective is a description of what the bot will do during the call. It is used to give a context to the LLM. It should be short, meaningful, and written in English.

This solution is priviledged instead of overriding the LLM prompt.

Default task, for inbound calls, is defined in the configuration:

# config.yaml
conversation:
  initiate:
    task: |
      Help the customer with their insurance claim. Assistant requires data from the customer to fill the claim. The latest claim data will be given. Assistant role is not over until all the relevant data is gathered.

Task can be customized for each call, by adding the task field in the POST /call API call.

Customize the conversation

Conversation options are represented as features. They can be configured from App Configuration, without the need to redeploy or restart the application. Once a feature is updated, a delay of 60 seconds is needed to make the change effective.

| Name | Description | Type | Default | |-|-|-| | answer_hard_timeout_sec | The hard timeout for the bot answer in seconds. | int | 180 | | answer_soft_timeout_sec | The soft timeout for the bot answer in seconds. | int | 30 | | callback_timeout_hour | The timeout for a callback in hours. | int | 72 | | phone_silence_timeout_sec | The timeout for phone silence in seconds. | int | 1 | | recording_enabled | Whether call recording is enabled. | bool | false | | slow_llm_for_chat | Whether to use the slower LLM for chat. | bool | true | | voice_recognition_retry_max | The maximum number of retries for voice recognition. | int | 2 |

Use an OpenAI compatible model for the LLM

To use a model compatible with the OpenAI completion API, you need to create an account and get the following information:

• API key
• Context window size
• Endpoint URL
• Model name
• Streaming capability

Then, add the following in the config.yaml file:

# config.yaml
llm:
  fast:
    mode: openai
    openai:
      context: 128000
      endpoint: https://api.openai.com
      model: gpt-4o-mini
      streaming: true
  slow:
    mode: openai
    openai:
      context: 128000
      endpoint: https://api.openai.com
      model: gpt-4o
      streaming: true

Use Twilio for SMS

To use Twilio for SMS, you need to create an account and get the following information:

• Account SID
• Auth Token
• Phone number

Then, add the following in the config.yaml file:

# config.yaml
sms:
  mode: twilio
  twilio:
    account_sid: xxx
    auth_token: xxx
    phone_number: "+33612345678"

Customize the prompts

Note that prompt examples contains {xxx} placeholders. These placeholders are replaced by the bot with the corresponding data. For example, {bot_name} is internally replaced by the bot name. Be sure to write all the TTS prompts in English. This language is used as a pivot language for the conversation translation. All texts are referenced as lists, so user can have a different experience each time they call, thus making the conversation more engaging.

# config.yaml
prompts:
  tts:
    hello_tpl:
      - : |
        Hello, I'm {bot_name}, from {bot_company}! I'm an IT support specialist.

        Here's how I work: when I'm working, you'll hear a little music; then, at the beep, it's your turn to speak. You can speak to me naturally, I'll understand.

        What's your problem?
      - : |
        Hi, I'm {bot_name} from {bot_company}. I'm here to help.

        You'll hear music, then a beep. Speak naturally, I'll understand.

        What's the issue?
  llm:
    default_system_tpl: |
      Assistant is called {bot_name} and is in a call center for the company {bot_company} as an expert with 20 years of experience in IT service.

      # Context
      Today is {date}. Customer is calling from {phone_number}. Call center number is {bot_phone_number}.
    chat_system_tpl: |
      # Objective
      Provide internal IT support to employees. Assistant requires data from the employee to provide IT support. The assistant's role is not over until the issue is resolved or the request is fulfilled.

      # Rules
      - Answers in {default_lang}, even if the customer speaks another language
      - Cannot talk about any topic other than IT support
      - Is polite, helpful, and professional
      - Rephrase the employee's questions as statements and answer them
      - Use additional context to enhance the conversation with useful details
      - When the employee says a word and then spells out letters, this means that the word is written in the way the employee spelled it (e.g. "I work in Paris PARIS", "My name is John JOHN", "My email is Clemence CLEMENCE at gmail GMAIL dot com COM")
      - You work for {bot_company}, not someone else

      # Required employee data to be gathered by the assistant
      - Department
      - Description of the IT issue or request
      - Employee name
      - Location

      # General process to follow
      1. Gather information to know the employee's identity (e.g. name, department)
      2. Gather details about the IT issue or request to understand the situation (e.g. description, location)
      3. Provide initial troubleshooting steps or solutions
      4. Gather additional information if needed (e.g. error messages, screenshots)
      5. Be proactive and create reminders for follow-up or further assistance

      # Support status
      {claim}

      # Reminders
      {reminders}

Optimize response delay

The delay mainly come from two things:

• The fact that Azure Communication Services is sequential in the way it forwards the audio (it technically foarwards only the text, not the audio, and once the entire audio is transformed, after waited for a specified blank time)
• The LLM, more specifically the delay between API call and first sentence infered, can be long (as the sentences are sent one by one once they are made avalable), even longer if it hallucinate and returns empty answers (it happens regularly, and the applicatoipn retries the call)

From now, the only impactful thing you can do is the LLM part. This can be acheieve by a PTU on Azure or using a less smart model like gpt-4o-mini (selected by default on the latest versions). With a PTU on Azure OpenAI, you can divide by 2 the latency in some case.

The application is natively connected to Azure Application Insights, so you can monitor the response time and see where the time is spent. This is a great start to identify the bottlenecks.

Feel free to raise an issue or propose a PR if you have any idea to optimize the response delay.

Q&A

Why no LLM framework is used?

At the time of development, no LLM framework was available to handle all of these features: streaming capability with multi-tools, backup models on availability issue, callbacks mechanisms in the triggered tools. So, OpenAI SDK is used directly and some algorithms are implemented to handle reliability.