---
name: ai-audiobook-narrator
title: "AI Audiobook Narrator"
description: "Submit text, AI Inference chunks into chapters with pacing/emotion markup, TTS narrates each chapter with consistent voice, stores final audio in Telnyx Cloud Storage."
language: python
framework: flask
telnyx_products: [AI Inference, Cloud Storage]
integrations: []
channel: [voice, api]
---

# AI Audiobook Narrator

Submit text, AI Inference chunks into chapters with pacing/emotion markup, TTS narrates each chapter with consistent voice, stores final audio in Telnyx Cloud Storage.

## Telnyx API Endpoints Used

- **AI Inference (chapter split)**: `POST /v2/ai/chat/completions` -- [ref](https://developers.telnyx.com/api/inference/chat-completions)
- **TTS Generate (narration)**: `POST /v2/ai/generate` -- [ref](https://developers.telnyx.com/api/inference/generate)
- **Cloud Storage (S3-compatible)**: `PutObject` via the AWS SDK (boto3) against `https://{region}.telnyxcloudstorage.com` -- [docs](https://developers.telnyx.com/docs/cloud-storage)

## Architecture

```
  API Request
        │
        ▼
  ┌──────────────────┐
  │ AI Inference      │ ── direction cues, rewrites
  └────────┬─────────┘
           │
           ▼
  ┌──────────────────┐
  │ TTS Generation    │ ── render audio
  │ (multiple takes/  │
  │  voices/languages)│
  └────────┬─────────┘
           │
           ├──► Cloud Storage
           └──► Cloud Storage (final assets)
```

## How It Works

1. Sends conversation to Telnyx AI Inference for processing
2. Converts response to speech via Telnyx TTS
3. Stores results in Telnyx Cloud Storage (S3-compatible, via boto3) and returns a presigned GET URL for each chapter

## Why Telnyx

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

- **Co-located inference** — LLM runs on the same network as voice traffic. Sub-200ms round trips.
- **Integrated storage** — S3-compatible storage co-located with voice and AI infrastructure.

## 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 | AI Inference model | [Docs](https://developers.telnyx.com/docs/inference/models) |
| `TTS_MODEL` | `string` | `telnyx/tts` | no | TTS model name | [Docs](https://developers.telnyx.com/docs/inference) |
| `BUCKET_NAME` | `string` | `audiobooks` | no | Cloud Storage bucket | [Portal](https://portal.telnyx.com/storage) |
| `TELNYX_STORAGE_REGION` | `string` | `us-central-1` | no | Cloud Storage region (selects the S3 endpoint host) | [Docs](https://developers.telnyx.com/docs/cloud-storage) |
| `DEFAULT_VOICE` | `string` | `nova` | no | Default narrator voice | [Docs](https://developers.telnyx.com/docs/inference) |

## Setup

```bash
git clone https://github.com/team-telnyx/telnyx-code-examples.git
cd telnyx-code-examples/ai-audiobook-narrator-python
cp .env.example .env
pip install -r requirements.txt
python app.py
```

### Webhook Configuration

```bash
ngrok http 5000
```

Set webhook URL in [Telnyx Portal](https://portal.telnyx.com):
- Call Control Application -> `https://<id>.ngrok.io/webhooks/voice`

## API Reference

### `POST /books/narrate`

```bash
curl -X POST http://localhost:5000/books/narrate \
  -H "Content-Type: application/json" \
  -d '{"title": "The Future of Infrastructure", "text": "Chapter 1: The shift from...", "voice": "nova"}'
```

**Response:**

```json
{"book_id": "book-a1b2c3d4", "title": "The Future of Infrastructure", "chapters": 5, "total_audio_mb": 12.4, "storage_urls": ["https://us-central-1.telnyxcloudstorage.com/audiobooks/book-a1b2c3d4/chapter-01.mp3?X-Amz-Algorithm=AWS4-HMAC-SHA256&X-Amz-Expires=3600&..."]}
```

### `GET /health`

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

```json
{"status": "ok"}
```

## Troubleshooting

- **Connection refused on port 5000**: App isn't running. Run `python app.py` and check no other process uses port 5000.
- **401 Unauthorized**: Your `TELNYX_API_KEY` is invalid. Generate a new one at [portal.telnyx.com/api-keys](https://portal.telnyx.com/api-keys).
- **AI response slow/empty**: Verify model name. See available models at [developers.telnyx.com](https://developers.telnyx.com/docs/inference/list-models).

## Related Examples

- [run-llm-inference-python](https://raw.githubusercontent.com/team-telnyx/telnyx-code-examples/main/run-llm-inference-python/README.md) - Standalone inference
- [build-voice-ai-agent-python](https://raw.githubusercontent.com/team-telnyx/telnyx-code-examples/main/build-voice-ai-agent-python/README.md) - Voice AI agent

## Resources

- [AI Inference Guide](https://developers.telnyx.com/docs/inference)
- [Call Control Guide](https://developers.telnyx.com/docs/voice/call-control)
- [Telnyx Developer Docs](https://developers.telnyx.com)
- [Telnyx Portal](https://portal.telnyx.com)