Prank Your Dad - AI Voice Demo

An AI-powered Father's Day surprise app that allows you to clone your voice on the spot and use it with an AI assistant to prank your dad.

Demo Concept

This application was built to demonstrate the Vapi platform's capabilities through a Father's Day scenario:

"This Father's Day, I decided to build an AI agent to call dad for me... using my voice. And he didn't notice."

Features

• Instant Voice Cloning: Clone your voice directly in the web app using ElevenLabs
• Real-time AI Assistant: Creates a Vapi assistant on the fly with your cloned voice
• Seamless Control: Mute/unmute AI assistant at any time
• Real-time Transcript: See the conversation as it happens
• Simple Setup: Clear instructions for the speaker-based prank

Prerequisites

• Vapi account with API keys
• ElevenLabs account with API key
• Node.js 18+ installed (or Bun)
• Two devices: your phone and computer
• Microphone for voice recording

Installation

1. Clone the repository

   git clone https://github.com/VapiAI/prank-your-dad.git
   cd prank-your-dad

2. Install dependencies

   bun install
   # -or-
   npm install

3. Configure environment variables

   Create a .env.local file with your API credentials:

   # Vapi API Keys
   NEXT_PUBLIC_VAPI_PUBLIC_KEY=your-vapi-public-key
   VAPI_PRIVATE_KEY=your-vapi-private-key
   
   # ElevenLabs API Key
   ELEVENLABS_API_KEY=your-elevenlabs-api-key
   
   # Optional: Pre-defined voice ID for demo purposes
   NEXT_PUBLIC_PREDEFINED_VOICE_ID=your-elevenlabs-voice-id
   

   Get your API keys from:

   • Vapi: https://dashboard.vapi.ai/
   • ElevenLabs: https://elevenlabs.io/

   For the pre-defined voice ID:

   • Create or clone a voice in ElevenLabs dashboard
   • Copy the voice ID from the voice settings
   • This is useful for demos where you want to skip the cloning step

4. Run the development server

   bun run dev
   # or npm run dev

5. Access the application Open http://localhost:3000 in your browser

Usage Instructions

Option 1: Clone Your Voice (Default Tab)

1. Enter a name for your voice (e.g., "My Voice")
2. Record 1-3 voice samples (10-30 seconds each)
3. Click "Clone Voice" to create your voice clone
4. Proceed to make the call

Option 2: Use Demo Voice Tab

1. Switch to "Use Demo Voice" tab
2. Skip voice cloning and use a pre-configured voice
3. Perfect for quick demos

Making the Call

1. Call Dad from Your Phone: Use your regular phone and put it on speaker
2. Computer on Speaker: Make sure your computer audio is also on speaker
3. Start AI Assistant: Click the button to activate the AI with your cloned voice
4. Control the Conversation:
   • Click "AI Muted" when you want to speak (dad only hears you)
   • Click "AI Active" to let the AI continue speaking
   • The transcript shows in real-time

Technical Implementation

• Frontend: Next.js 15 with TypeScript
• UI Components: shadcn/ui with Tailwind CSS v4
• Voice Cloning: ElevenLabs Instant Voice Cloning API
• Voice AI: Vapi Web SDK with inline assistant configuration
• Architecture: Client-side voice control with server-side voice cloning

Important Notes

• Both devices must be on speaker for the prank to work
• The AI uses your freshly cloned voice from ElevenLabs
• Record clear voice samples without background noise for best results
• Ensure good internet connection for real-time voice synthesis
• Test the setup before the actual call

Contributing

Issues and pull requests are welcome. Please ensure any changes maintain the demo's simplicity and effectiveness.

License

MIT License - See LICENSE file for details

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Built with ❤️ for Father's Day using Vapi AI and ElevenLabs