Voice Scheduling Agent

A real-time voice assistant that schedules meetings by collecting your name, preferred date & time, and an optional meeting title — then creates a real Google Calendar event. Tech Stack: Vapi · Next.js · Google Calendar · Vercel

Demo Screen Recording

https://drive.google.com/file/d/1QeG3a26TDME5Wf7u1FDg6e6aZkx5S7K8/view?usp=sharing)

Live Demo:

https://voice-scheduling-agent-five.vercel.app/

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How to test it

1. Open the link above in your browser

2. Click Start Scheduling

3. Allow microphone access when prompted

4. Speak naturally — for example:

   "I'd like to schedule a meeting tomorrow at 3pm"

5. The assistant will ask for your name and confirm the details

6. Once confirmed, a real Google Calendar event will be created

No account or login is required to test the voice flow. Calendar events are created on the demo Google Calendar connected to this deployment.

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How the Calendar Integration Works

This project uses Vapi's built-in Google Calendar integration rather than a custom API implementation.

1. In the Vapi dashboard, navigate to Integrations → Tools Provider → Google Calendar and connect a Google account. This authorizes Vapi to create events on behalf of that account using OAuth.
2. The assistant is configured with the google.calendar.event.create tool inside lib/vapi-config.ts. This tells Vapi which tool to call and what parameters to pass once the user has confirmed their details.
3. During the call, once the user confirms their name, date, time, and optional meeting title, Vapi calls the tool in real time and the event is created immediately.
4. The webhook at /api/vapi/webhook receives the call status and tool call results, which can be used for logging or any follow-up actions.

Example Logs: Successful Event Creation

When the user confirms the meeting details, Vapi automatically triggers the Google Calendar integration. Here is a real payload showing the AI passing the exact arguments to the function, and Google Calendar returning the confirmed event link:

// Vapi calls the predefined Calendar tool
{
  "role": "tool_calls",
  "toolCalls": [
    {
      "type": "function",
      "function": {
        "name": "google_calendar_tool",
        "arguments": "{\n  \"summary\": \"Catch-up Call with Sam\",\n  \"timeZone\": \"America/New_York\",\n  \"startDateTime\": \"2026-02-26T14:00:00\",\n  \"endDateTime\": \"2026-02-26T14:30:00\",\n  \"attendees\": [\"susilkessavsb@gmail.com\"]\n}"
      }
    }
  ]
}

// Google Calendar authenticates and returns the successful event link
{
  "name": "google_calendar_tool",
  "role": "tool_call_result",
  "result": "{\n  \"status\": \"confirmed\",\n  \"htmlLink\": \"https://www.google.com/calendar/event?eid=...\",\n  \"summary\": \"Catch-up Call with Sam\",\n  \"start\": {\n    \"dateTime\": \"2026-02-26T14:00:00-05:00\",\n    \"timeZone\": \"America/New_York\"\n  },\n  \"attendees\": [\n    {\n      \"email\": \"susilkessavsb@gmail.com\",\n      \"responseStatus\": \"needsAction\"\n    }\n  ]\n}"
}

No direct Google API calls are made from the app itself — Vapi handles the OAuth token, the API request, and error handling end to end.

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Features

• Natural voice conversation to schedule meetings
• Real Google Calendar event creation
• GPT-4o powered with context awareness
• Live transcript display during calls
• Animated voice orb with volume-reactive UI
• One-click Vercel deployment

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Quick Start

1. Install dependencies

npm install

2. Configure environment variables

cp .env.example .env.local

Edit .env.local with your keys:

NEXT_PUBLIC_VAPI_PUBLIC_KEY=your_vapi_public_key_here
VAPI_PRIVATE_KEY=your_vapi_private_key_here

3. Set up Vapi and Google Calendar

1. Create an account at dashboard.vapi.ai
2. Go to Organization Settings and copy your Public Key and Private Key
3. Go to Integrations → Tools Provider → Google Calendar, click Connect, and authorize
4. Optionally, create an assistant in the dashboard and add Google Calendar tools

The app can either use a pre-configured assistant ID (NEXT_PUBLIC_VAPI_ASSISTANT_ID) or create the assistant inline using the config in lib/vapi-config.ts.

4. Run locally

npm run dev

Open http://localhost:3000 and click Start Scheduling.

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Deploy to Vercel

Option A — CLI:

npx vercel

Option B — GitHub:

1. Push this repo to GitHub
2. Import it at vercel.com/new
3. Add your environment variables in the Vercel dashboard
4. Deploy

After deploying, set your Server URL in the Vapi Dashboard:

https://your-app.vercel.app/api/vapi/webhook

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Project Structure

├── app/
│   ├── api/vapi/webhook/
│   │   └── route.ts          # Vapi webhook handler
│   ├── globals.css            # Global styles & animations
│   ├── layout.tsx             # Root layout
│   └── page.tsx               # Main voice UI page
├── lib/
│   └── vapi-config.ts         # Vapi assistant configuration
├── .env.example               # Environment variable template
└── README.md

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How It Works

1. User clicks Start Scheduling — the @vapi-ai/web SDK opens a WebSocket to Vapi
2. Vapi orchestrates the conversation using GPT-4o with the system prompt in lib/vapi-config.ts
3. The user speaks naturally — name, date/time, and optional title are collected conversationally
4. The assistant confirms the details and calls the google.calendar.event.create tool
5. Vapi's built-in Google Calendar integration creates the event
6. The webhook at /api/vapi/webhook receives status updates and call reports

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License

MIT