---
name: ai-appointment-booking-sms-flow
title: "AI Appointment Booking SMS Flow"
description: "AI Appointment Booking SMS Flow — guided SMS booking with available slot selection."
language: python
framework: flask
telnyx_products: [SMS/MMS, AI Inference]
channel: [sms]
---

# AI Appointment Booking SMS Flow

AI Appointment Booking SMS Flow — guided SMS booking with available slot selection.

## Telnyx API Endpoints Used

- **Send Message**: `POST /v2/messages` — [API reference](https://developers.telnyx.com/api/messaging/send-message)
- **AI Inference**: `POST /v2/ai/chat/completions` — [API reference](https://developers.telnyx.com/api/inference/chat-completions)

## Telnyx Webhook Events

This app handles these webhook events ([Messaging docs](https://developers.telnyx.com/docs/api/v2/messaging)):

- `message.received` — Inbound SMS/MMS received

## Architecture

```
  Inbound SMS/MMS
        │
        ▼
  ┌──────────────────┐
  │ Parse message     │
  └────────┬─────────┘
           │
           ▼
  ┌──────────────────┐
  │ AI Inference      │
  │ • Appointment scheduling│
  └────────┬─────────┘
           │ ◄──── conversation loop
           │
           └──► SMS notification

  State: In-memory dict
```

## Environment Variables

Copy `.env.example` to `.env` and fill in:

| Variable | Type | Example | Required | Description | Where to get it |
|----------|------|---------|----------|-------------|-----------------|
| `TELNYX_API_KEY` | `string` | `KEY0123456789ABCDEF` | **yes** | Telnyx API v2 key | [Portal](https://portal.telnyx.com/api-keys) |
| `AI_MODEL` | `string` | `moonshotai/Kimi-K2.6` | no | Telnyx AI Inference model name | [Portal](https://developers.telnyx.com/docs/inference/models) |
| `BOOKING_NUMBER` | `string` | `your_value` | **yes** | Booking number | — |
| `MESSAGING_PROFILE_ID` | `string` | `40017b7e-b3c0-4ac3-8740-9c3c5a0a0e0c` | no | Messaging profile ID | [Portal](https://portal.telnyx.com/messaging/profiles) |
| `PORT` | `integer` | `5000` | no | HTTP server port | — |

## Setup

```bash
git clone https://github.com/team-telnyx/telnyx-code-examples.git
cd telnyx-code-examples/ai-appointment-booking-sms-flow-python
cp .env.example .env    # ← fill in your credentials
pip install -r requirements.txt
python app.py           # starts on http://localhost:5000
```

### Webhook Configuration

1. Expose your local server:

   ```bash
   ngrok http 5000
   ```

2. Copy the HTTPS URL and configure in [Telnyx Portal](https://portal.telnyx.com):

   - **Messaging Profile** → Inbound Webhook URL → `https://<id>.ngrok.io/webhooks/sms`

## API Reference

### `GET /bookings`

Returns bookings

```bash
curl http://localhost:5000/bookings
```

**Response:**

```json
{
  "appointments": [
    {
      "id": "appt-7821",
      "date": "2026-07-18",
      "time": "14:30",
      "provider": "Dr. Smith",
      "patient_phone": "+1212555****",
      "status": "confirmed"
    }
  ]
}
```

### `GET /health`

Returns health

```bash
curl http://localhost:5000/health
```

**Response:**

```json
{
  "status": "ok",
  "uptime_seconds": 3842,
  "active_sessions": 2,
  "version": "1.0.0"
}
```

## Webhook Endpoints

### `POST /webhooks/messaging`

Receives [Telnyx Messaging](https://developers.telnyx.com/docs/messaging) webhook events.

**Example payload:**

```json
{
  "data": {
    "event_type": "message.received",
    "id": "f5d7a7e0-1234-5678-9abc-def012345678",
    "occurred_at": "2026-07-15T14:30:00.000Z",
    "payload": {
      "id": "f5d7a7e0-1234-5678-9abc-def012345678",
      "direction": "inbound",
      "type": "SMS",
      "from": {
        "phone_number": "+12125551234",
        "carrier": "Verizon",
        "line_type": "Wireless"
      },
      "to": [{"phone_number": "+13105559876"}],
      "text": "Hello, I need help",
      "media": [],
      "received_at": "2026-07-15T14:30:00.000Z",
      "messaging_profile_id": "40017b7e-b3c0-4ac3-8740-9c3c5a0a0e0c"
    },
    "record_type": "event"
  }
}
```

## Troubleshooting

| Issue | Cause | Fix |
|-------|-------|-----|
| `401 Unauthorized` | Invalid or missing API key | Verify `TELNYX_API_KEY` in `.env` matches your key in the [Portal](https://portal.telnyx.com/api-keys) |
| Webhook not received | Local server not publicly reachable | Expose it with a tunnel (e.g. ngrok) and set the webhook URL in the [Telnyx Portal](https://portal.telnyx.com) |
| `422 Unprocessable Entity` | Missing or malformed request fields | Check the request body against the API Reference above |

## Related Examples

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- [Accounting Tax Season Line (Python)](https://raw.githubusercontent.com/team-telnyx/telnyx-code-examples/main/accounting-tax-season-line-python/README.md)
- [After Hours Nurse Triage (Python)](https://raw.githubusercontent.com/team-telnyx/telnyx-code-examples/main/after-hours-nurse-triage-python/README.md)
- [AI Appointment Reminder SMS Voice (Python)](https://raw.githubusercontent.com/team-telnyx/telnyx-code-examples/main/ai-appointment-reminder-sms-voice-python/README.md)
- [Autonomous Outbound Sales Agent (Python)](https://raw.githubusercontent.com/team-telnyx/telnyx-code-examples/main/autonomous-outbound-sales-agent-python/README.md)

## Resources

- [Messaging Guide](https://developers.telnyx.com/docs/messaging)
- [AI Inference Guide](https://developers.telnyx.com/docs/inference)
- [Telnyx Developer Docs](https://developers.telnyx.com)
- [Telnyx Portal](https://portal.telnyx.com)

## Why Telnyx

Telnyx is an **AI Communications Infrastructure** platform — voice, messaging, SIP, AI, and IoT on one private, global network.