[Workshop] Build Your First AI Voice Bot — DevConf Pune 2026 - Creds

General
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Welcome to the Exotel Developer Network workshop! :studio_microphone:

You’re about to build a production-ready voice AI agent that integrates Google’s AI services with Exotel’s telephony platform. By the end of this workshop, you’ll have a working bot that:

:white_check_mark: Understands speech in real-time (Google Cloud STT - Chirp 3)
:white_check_mark: Responds intelligently (Google Gemini LLM)
:white_check_mark: Speaks naturally (Google Cloud TTS - Chirp3-HD)
:white_check_mark: Receives calls via Exotel (WebSocket streaming)

:clipboard: Setup Checklist

Follow these steps in order:

Step 1: Clone the Repository

git clone https://github.com/exotel/voicebot-quick-starter.git
cd voicebot-quick-starter

The repo contains everything you need — bot pipeline, WebRTC runner, and Exotel telephony runner. Don’t dive into the code yet — just clone it.

:open_book: Full Setup Guide on GitHub

Step 2: Exotel Credentials

These credentials authenticate your bot with Exotel’s voice API. Valid during the workshop only (expires post-event).

Credential Value
API Key
API Token
Account SID
Virtual Phone Number (Exophone)

When you need this: Step 4 in the GitHub guide (Exotel Telephony section)

Step 3: Google Cloud Credentials

Your bot uses three Google Cloud services. Here are your credentials:

What it’s for: Accessing Vertex AI, Cloud Speech-to-Text, and Cloud Text-to-Speech APIs

Service Account JSON Key File

Download your GCP service account JSON file here: <File Remove>

This file enables your bot to authenticate with Google Cloud APIs.

:warning: Important:

  • Download this file and save it in your voicebot-quick-starter/ directory

  • Never commit this file to Git — it’s already in .gitignore

  • This key expires after the workshop

Where to place it: See Step 4 in the GitHub guide (Google Cloud Setup)

3c. The AI Services Your Bot Uses

Your bot is configured with these Google Cloud services:

Service Component Details
Speech-to-Text Google Cloud STT Model: Chirp 3 (optimised for Indian English & Hindi)
LLM Vertex AI Model: Gemini 2.5 Flash Lite (fast & affordable)
Text-to-Speech Google Cloud TTS Voice: en-US-Chirp3-HD (natural, high-quality)

:white_check_mark: All services are pre-configured in the code — just authenticate with your service account JSON.

Step 4: Set Environment Variables

Inside your voicebot-quick-starter/ directory, create a .env file:

# .env
GOOGLE_APPLICATION_CREDENTIALS=./your-service-account.json

Replace your-service-account.json with the actual filename of your downloaded JSON key.

Step 5: Install Dependencies & Run

# Install Python 3.10+ and dependencies
pip install -r requirements.txt

# Run the WebRTC demo (browser-based)
python default_runner.py

Open http://localhost:7860/client in your browser and start talking to your bot!

:magnifying_glass_tilted_left: What’s Happening Behind the Scenes

When you run the bot:

  1. You speak → Google Cloud STT transcribes your voice

  2. Bot understands → Gemini LLM generates a response

  3. Bot speaks back → Google Cloud TTS converts response to natural speech

  4. Loop repeats → Real-time conversation

For incoming phone calls (Exotel), the same pipeline runs, but over WebSocket instead of WebRTC.

:sos_button: Quick Troubleshooting

Issue Solution
“GOOGLE_APPLICATION_CREDENTIALS not found” Check that your .env file exists and points to the correct JSON file path
“No audio output” Make sure your browser allows microphone access (WebRTC)
“Connection refused” Ensure Python dependencies installed: pip install -r requirements.txt

For more help, check the GitHub Troubleshooting Section

:wrapped_gift: Express Interest for Swag

Loved building this? Let us know! We’ve got Exotel Developer Network stickers, hoodies, and more for workshop participants.

Express Interest for Swag

:books: What’s Next After This Workshop?

  • Customize the bot → Edit the system prompt in bot.py to change its personality

  • Deploy to production → Run it on your server with ngrok or cloud hosting

  • Connect your own phone number → Set up incoming call handling

  • Explore other AI models → Swap Gemini for Claude, OpenAI, or Groq

  • Get community help → Ask questions in the EDN Forums

:open_book: Documentation

:person_raising_hand: Questions?

Happy coding! Let’s build the AI voice revolution in India. :rocket:

Credentials are valid only for DevConf Pune 2026 (Feb 13, 2026) and will expire automatically post-event.

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Hi Trying, let’s see if this works

1 Like
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Would love to know if you were able to make it work. If not, feel free to create a thread about your progress, and we will be happy to solve it collectively.