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🤖 Supernal TTS - Complete LLM Integration Guide

This is a comprehensive guide designed to be copied and pasted into an LLM conversation to give it complete context about integrating Supernal TTS.

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Quick Summary​

Supernal TTS is a text-to-speech API service with multiple provider support (OpenAI, Cartesia, Azure, Mock). It provides REST API endpoints, JavaScript SDK, and embeddable web widgets for converting text to speech.

Core Endpoints​

Base URL: https://tts.supernal.ai (or http://localhost:3030 for local development)

1. Generate Speech​

POST /api/v1/generate
Content-Type: application/json

{
  "text": "Text to convert to speech",
  "options": {
    "provider": "openai",     # Options: "openai", "cartesia", "azure", "mock"
    "voice": "coral",         # Provider-specific voice name
    "speed": 1.0,             # Range: 0.25 - 4.0
    "instructions": "optional tone/style instructions for OpenAI"
  }
}

Response:

{
  "audioUrl": "https://tts.supernal.ai/api/v1/audio/abc123...",
  "hash": "abc123...",
  "metadata": {
    "provider": "openai",
    "voice": "coral",
    "duration": 5.2,
    "size": 83840
  }
}

2. Retrieve Audio​

GET /api/v1/audio/{hash}

Returns the audio file (typically MP3 format).

3. Get Audio Metadata​

GET /api/v1/audio/{hash}/metadata

Returns metadata about the audio file without downloading it.

4. List Available Providers​

GET /api/v1/providers

Returns list of configured and available providers.

5. Health Check​

GET /health

Returns service status and available providers.

Provider Options​

OpenAI​

  • Voices: alloy, echo, fable, onyx, nova, shimmer, coral
  • Best for: High-quality natural speech
  • Latency: ~200ms
  • Cost: $15-30 per million characters
  • Special features: instructions parameter for tone control

Cartesia​

  • Best for: Real-time applications requiring ultra-low latency
  • Latency: ~Low latency (fastest)
  • Cost: ~$24 per million characters
  • Special features: Emotion control

Azure​

  • Best for: Budget-conscious projects
  • Latency: ~300ms
  • Cost: $0-16 per million characters (500K free tier)
  • Voices: en-US-JennyNeural, en-US-GuyNeural, en-US-AriaNeural, etc.

Mock​

  • Best for: Testing without API keys
  • Latency: ~500ms
  • Cost: Free
  • Note: Returns test audio, no real TTS generation

JavaScript SDK Usage​

import { TTSClient } from '@supernal-tts/client';

// Initialize client
const client = new TTSClient({
  apiUrl: 'https://tts.supernal.ai'
});

// Generate speech
const result = await client.generate({
  text: "Hello from Supernal TTS!",
  options: {
    provider: 'openai',
    voice: 'coral'
  }
});

// Use the audio URL
console.log(result.audioUrl);

// Get metadata
const metadata = await client.getMetadata(result.hash);

Web Widget Integration​

Simple Button Widget​

<!DOCTYPE html>
<html>
<head>
  <script src="https://cdn.supernal.ai/widget/tts-widget.js"></script>
</head>
<body>
  <div class="supernal-tts-widget" 
       data-text="Your text here"
       data-voice="coral"
       data-provider="openai">
  </div>

  <script>
    const tts = new SupernalTTS({
      apiUrl: 'https://tts.supernal.ai',
      provider: 'openai',
      voice: 'coral'
    });
  </script>
</body>
</html>

Advanced Widget with Controls​

<div class="supernal-tts-widget" 
     data-text="Your text here"
     data-voice="coral"
     data-provider="openai"
     data-speed="1.0"
     data-controls="true">
</div>

The advanced widget includes voice selection, speed control, position seek bar, and time display.

Environment Setup​

When deploying or running locally, set these environment variables:

# Required for specific providers
OPENAI_API_KEY=sk-...
CARTESIA_API_KEY=...
AZURE_API_KEY=...
AZURE_REGION=eastus

# Optional configuration
PORT=3030
NODE_ENV=production
CACHE_DIR=.tts-cache
ENABLE_MOCK_PROVIDER=true
DEFAULT_PROVIDER=openai

Common Integration Patterns​

1. Blog Audio Generation​

async function addAudioToBlogPost(postContent) {
  const client = new TTSClient({ apiUrl: 'https://tts.supernal.ai' });
  
  const result = await client.generate({
    text: postContent,
    options: {
      provider: 'openai',
      voice: 'fable'
    }
  });
  
  return result.audioUrl;
}

2. Batch Processing​

async function convertMultiplePosts(posts) {
  const client = new TTSClient({ apiUrl: 'https://tts.supernal.ai' });
  
  const results = await Promise.all(
    posts.map(post => client.generate({
      text: post.content,
      options: { provider: 'openai', voice: 'nova' }
    }))
  );
  
  return results;
}

3. Real-time Chatbot Response​

async function speakChatbotResponse(message) {
  const client = new TTSClient({ apiUrl: 'https://tts.supernal.ai' });
  
  // Use Cartesia for lowest latency
  const result = await client.generate({
    text: message,
    options: {
      provider: 'cartesia',
      voice: 'confident-british-man'
    }
  });
  
  // Play audio immediately
  const audio = new Audio(result.audioUrl);
  audio.play();
}

Cost Optimization​

  1. Use caching: The service automatically caches identical text+voice combinations
  2. Choose appropriate provider:
    • Testing: Use mock provider
    • Budget: Use azure (especially within 500K char/month free tier)
    • Quality: Use openai
    • Speed: Use cartesia
  3. Pre-generate static content: For content that doesn't change, generate audio once

Error Handling​

try {
  const result = await client.generate({
    text: "Hello world!",
    options: { provider: 'openai', voice: 'coral' }
  });
  return result.audioUrl;
} catch (error) {
  if (error.status === 503) {
    // Provider unavailable - fallback to mock
    return await client.generate({
      text: "Hello world!",
      options: { provider: 'mock' }
    });
  }
  throw error;
}

Testing Locally​

# 1. Clone repository
git clone https://github.com/supernalintelligence/supernal-nova.git
cd supernal-nova/families/supernal-tts

# 2. Install dependencies
npm install

# 3. Set environment variables
cp .env.example .env
# Edit .env and add your API keys

# 4. Start server
npm run dev

# 5. Test with curl
curl -X POST http://localhost:3030/api/v1/generate \
  -H "Content-Type: application/json" \
  -d '{"text": "Test", "options": {"provider": "mock"}}'

Deployment​

The service can be deployed as:

  • Docker container: See docker-compose.yml
  • Vercel serverless: See vercel.json
  • Node.js application: Run node npm-packages/supernal-tts-server/bin/supernal-tts.js

Support & Documentation​

📋 Quick Copy-Paste Examples​

cURL Example​

curl -X POST https://tts.supernal.ai/api/v1/generate \
  -H "Content-Type: application/json" \
  -d '{
    "text": "Welcome to Supernal TTS!",
    "options": {
      "provider": "openai",
      "voice": "coral"
    }
  }'

JavaScript Fetch Example​

const response = await fetch('https://tts.supernal.ai/api/v1/generate', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    text: "Welcome to Supernal TTS!",
    options: { provider: 'openai', voice: 'coral' }
  })
});
const data = await response.json();
console.log(data.audioUrl);

Python Example​

import requests

response = requests.post(
    'https://tts.supernal.ai/api/v1/generate',
    json={
        'text': 'Welcome to Supernal TTS!',
        'options': {
            'provider': 'openai',
            'voice': 'coral'
        }
    }
)
data = response.json()
print(data['audioUrl'])

License: Fair Source License (see LICENSE file for commercial use terms)

Last Updated: October 2025

📦 Complete Code Examples​

React Blog Component (Full Implementation)​

import React, { useState, useRef, useEffect } from 'react';

const TTS_API_URL = 'https://tts.supernal.ai/api/v1';

function TTSButton({ text, voice = 'nova', speed = 1.0 }) {
  const [isLoading, setIsLoading] = useState(false);
  const [isPlaying, setIsPlaying] = useState(false);
  const [error, setError] = useState(null);
  const [progress, setProgress] = useState(0);
  const audioRef = useRef(null);

  useEffect(() => {
    return () => {
      if (audioRef.current) {
        audioRef.current.pause();
        audioRef.current = null;
      }
    };
  }, []);

  const handleTimeUpdate = () => {
    if (audioRef.current) {
      const percent = (audioRef.current.currentTime / audioRef.current.duration) * 100;
      setProgress(percent);
    }
  };

  const handlePlayPause = async () => {
    if (isPlaying && audioRef.current) {
      audioRef.current.pause();
      setIsPlaying(false);
      return;
    }

    if (audioRef.current && audioRef.current.src) {
      audioRef.current.play();
      setIsPlaying(true);
      return;
    }

    setIsLoading(true);
    setError(null);
    
    try {
      const response = await fetch(`${TTS_API_URL}/generate`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({
          text,
          options: {
            provider: 'openai',
            voice,
            speed,
            format: 'mp3'
          }
        })
      });

      if (!response.ok) {
        throw new Error(`HTTP error! status: ${response.status}`);
      }

      const data = await response.json();
      
      if (!audioRef.current) {
        audioRef.current = new Audio();
        audioRef.current.onended = () => {
          setIsPlaying(false);
          setProgress(0);
        };
        audioRef.current.ontimeupdate = handleTimeUpdate;
        audioRef.current.onerror = () => {
          setError('Failed to load audio');
          setIsPlaying(false);
          setIsLoading(false);
        };
      }
      
      audioRef.current.src = `${TTS_API_URL}${data.url}`;
      await audioRef.current.play();
      setIsPlaying(true);
      
    } catch (err) {
      console.error('TTS Error:', err);
      setError(err.message);
    } finally {
      setIsLoading(false);
    }
  };

  return (
    <div style={{ margin: '1rem 0' }}>
      <button 
        onClick={handlePlayPause} 
        disabled={isLoading}
        style={{
          padding: '0.75rem 1.5rem',
          fontSize: '1rem',
          backgroundColor: isPlaying ? '#dc3545' : '#007bff',
          color: 'white',
          border: 'none',
          borderRadius: '4px',
          cursor: isLoading ? 'not-allowed' : 'pointer'
        }}
      >
        {isLoading ? '⏳ Generating...' : isPlaying ? '⏸️ Pause' : '🔊 Listen'}
      </button>
      
      {(isPlaying || progress > 0) && (
        <div style={{
          width: '100%',
          height: '4px',
          backgroundColor: '#e9ecef',
          borderRadius: '2px',
          marginTop: '0.5rem',
          overflow: 'hidden'
        }}>
          <div style={{
            width: `${progress}%`,
            height: '100%',
            backgroundColor: '#007bff',
            transition: 'width 0.1s linear'
          }} />
        </div>
      )}
      
      {error && <div style={{ color: '#dc3545', marginTop: '0.5rem' }}>⚠️ {error}</div>}
    </div>
  );
}

// Usage in blog post
function BlogPost({ title, author, content }) {
  const [selectedVoice, setSelectedVoice] = useState('nova');
  const fullText = `${title}. By ${author}. ${content}`;
  
  return (
    <article>
      <h2>{title}</h2>
      <p>By {author}</p>
      
      <select 
        value={selectedVoice} 
        onChange={(e) => setSelectedVoice(e.target.value)}
        style={{ marginBottom: '1rem' }}
      >
        <option value="nova">Nova (Warm female)</option>
        <option value="fable">Fable (British)</option>
        <option value="onyx">Onyx (Deep)</option>
        <option value="alloy">Alloy (Neutral)</option>
      </select>
      
      <TTSButton text={fullText} voice={selectedVoice} />
      
      <div>{content}</div>
    </article>
  );
}

export default BlogPost;

Node.js CLI Tool (Complete Implementation)​

Save this as tts-cli.js:

#!/usr/bin/env node

const fs = require('fs');
const path = require('path');
const http = require('http');
const https = require('https');

const TTS_API_URL = process.env.TTS_API_URL || 'http://localhost:3030';

// Make HTTP request helper
function makeRequest(url, options = {}) {
  return new Promise((resolve, reject) => {
    const lib = url.startsWith('https:') ? https : http;
    
    const req = lib.request(url, {
      method: options.method || 'GET',
      headers: {
        'Content-Type': 'application/json',
        ...options.headers
      }
    }, (res) => {
      if (options.binary) {
        const chunks = [];
        res.on('data', chunk => chunks.push(chunk));
        res.on('end', () => resolve(Buffer.concat(chunks)));
      } else {
        let data = '';
        res.on('data', chunk => data += chunk);
        res.on('end', () => {
          try {
            resolve(JSON.parse(data));
          } catch (e) {
            resolve(data);
          }
        });
      }
    });

    req.on('error', reject);
    
    if (options.body) {
      req.write(JSON.stringify(options.body));
    }
    
    req.end();
  });
}

// Generate TTS from text
async function generateTTS(text, options = {}) {
  const {
    voice = 'fable',
    provider = 'openai',
    speed = 1.0,
    output = 'output.mp3'
  } = options;

  console.log(`🎙️  Generating TTS...`);
  console.log(`   Text: "${text.substring(0, 50)}${text.length > 50 ? '...' : ''}"`);
  console.log(`   Provider: ${provider}`);
  console.log(`   Voice: ${voice}`);
  
  try {
    const response = await makeRequest(`${TTS_API_URL}/api/v1/generate`, {
      method: 'POST',
      body: {
        text,
        options: { provider, voice, speed, format: 'mp3' }
      }
    });

    if (response.error) {
      console.error(`❌ Error: ${response.error}`);
      process.exit(1);
    }

    console.log(`✅ Generated successfully!`);
    console.log(`   Hash: ${response.hash}`);
    console.log(`   Duration: ${response.duration}s`);
    console.log(`   URL: ${TTS_API_URL}${response.audioUrl}`);

    // Download audio file
    console.log(`\n📥 Downloading audio to: ${output}`);
    
    const audioData = await makeRequest(`${TTS_API_URL}${response.audioUrl}`, {
      binary: true
    });
    
    fs.writeFileSync(output, audioData);
    console.log(`✅ Audio saved: ${output} (${audioData.length} bytes)`);
    
    return { hash: response.hash, file: output };
    
  } catch (error) {
    console.error(`❌ Request failed: ${error.message}`);
    process.exit(1);
  }
}

// Process text file
async function processFile(filePath, options = {}) {
  if (!fs.existsSync(filePath)) {
    console.error(`❌ File not found: ${filePath}`);
    process.exit(1);
  }

  const text = fs.readFileSync(filePath, 'utf-8').trim();
  if (!text) {
    console.error(`❌ File is empty: ${filePath}`);
    process.exit(1);
  }

  console.log(`📄 Processing file: ${filePath}`);
  console.log(`   Length: ${text.length} characters`);

  const outputFile = options.output || `${path.basename(filePath, path.extname(filePath))}.mp3`;
  
  return await generateTTS(text, { ...options, output: outputFile });
}

// Show help
function showHelp() {
  console.log(`
🎙️  Supernal TTS CLI Tool

Usage:
  node tts-cli.js generate --text "Your text" [options]
  node tts-cli.js file --file input.txt [options]

Commands:
  generate          Generate audio from text
  file              Process text file

Options:
  --text <text>     Text to convert to speech
  --file <path>     Text file to process
  --output <path>   Output audio file path (default: output.mp3)
  --voice <voice>   Voice to use (default: fable)
  --provider <name> Provider to use (default: openai)
  --speed <float>   Speech speed 0.25-4.0 (default: 1.0)

Environment Variables:
  TTS_API_URL       API server URL (default: http://localhost:3030)

Examples:
  # Generate from text
  node tts-cli.js generate --text "Hello world" --voice nova --output hello.mp3

  # Process a file
  node tts-cli.js file --file article.txt --voice fable --output article.mp3
`);
}

// Parse command line arguments
function parseArgs() {
  const args = process.argv.slice(2);
  const options = {
    command: args[0],
    text: null,
    file: null,
    output: null,
    voice: 'fable',
    provider: 'openai',
    speed: 1.0
  };

  for (let i = 1; i < args.length; i += 2) {
    const flag = args[i];
    const value = args[i + 1];
    
    switch (flag) {
      case '--text': options.text = value; break;
      case '--file': options.file = value; break;
      case '--output': options.output = value; break;
      case '--voice': options.voice = value; break;
      case '--provider': options.provider = value; break;
      case '--speed': options.speed = parseFloat(value); break;
    }
  }

  return options;
}

// Main function
async function main() {
  const options = parseArgs();

  if (!options.command || options.command === 'help') {
    showHelp();
    return;
  }

  try {
    switch (options.command) {
      case 'generate':
        if (!options.text) {
          console.error('❌ --text is required for generate command');
          process.exit(1);
        }
        await generateTTS(options.text, options);
        break;

      case 'file':
        if (!options.file) {
          console.error('❌ --file is required for file command');
          process.exit(1);
        }
        await processFile(options.file, options);
        break;

      default:
        console.error(`❌ Unknown command: ${options.command}`);
        showHelp();
        process.exit(1);
    }
  } catch (error) {
    console.error(`❌ Command failed: ${error.message}`);
    process.exit(1);
  }
}

// Run if called directly
if (require.main === module) {
  main().catch(console.error);
}

module.exports = { generateTTS, processFile };

Make it executable:

chmod +x tts-cli.js

# Usage examples
./tts-cli.js generate --text "Hello world" --voice nova --output hello.mp3
./tts-cli.js file --file article.txt --voice fable --output article.mp3

Static HTML Widget Demo​

Save this as demo.html:

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Supernal TTS Widget Demo</title>
    <style>
        body {
            font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
            max-width: 800px;
            margin: 0 auto;
            padding: 2rem;
            line-height: 1.6;
        }
        
        .tts-button {
            background: #007bff;
            color: white;
            border: none;
            padding: 0.75rem 1.5rem;
            font-size: 1rem;
            border-radius: 4px;
            cursor: pointer;
            margin: 1rem 0;
        }
        
        .tts-button:hover {
            background: #0056b3;
        }
        
        .tts-button:disabled {
            background: #6c757d;
            cursor: not-allowed;
        }
        
        .progress-bar {
            width: 100%;
            height: 4px;
            background: #e9ecef;
            border-radius: 2px;
            margin-top: 0.5rem;
            overflow: hidden;
        }
        
        .progress-fill {
            height: 100%;
            background: #007bff;
            transition: width 0.1s linear;
        }
        
        .blog-post {
            background: #f8f9fa;
            padding: 2rem;
            border-radius: 8px;
            margin: 2rem 0;
        }
    </style>
</head>
<body>
    <h1>🎙️ Supernal TTS Demo</h1>
    
    <div class="blog-post">
        <h2>Sample Blog Post</h2>
        <p id="content">
            Welcome to Supernal TTS! This is a demonstration of text-to-speech technology.
            With just a click, you can listen to any written content. This makes information
            more accessible and allows you to consume content while multitasking.
        </p>
        
        <select id="voice-select">
            <option value="nova">Nova (Warm female)</option>
            <option value="fable">Fable (British)</option>
            <option value="onyx">Onyx (Deep)</option>
            <option value="alloy">Alloy (Neutral)</option>
        </select>
        
        <button id="play-button" class="tts-button">🔊 Listen to Article</button>
        <div id="progress" class="progress-bar" style="display: none;">
            <div id="progress-fill" class="progress-fill"></div>
        </div>
        <div id="error" style="color: #dc3545; margin-top: 0.5rem;"></div>
    </div>

    <script>
        const API_URL = 'https://tts.supernal.ai/api/v1';
        
        const playButton = document.getElementById('play-button');
        const voiceSelect = document.getElementById('voice-select');
        const content = document.getElementById('content');
        const progressBar = document.getElementById('progress');
        const progressFill = document.getElementById('progress-fill');
        const errorDiv = document.getElementById('error');
        
        let audio = null;
        let isPlaying = false;

        playButton.addEventListener('click', async () => {
            if (isPlaying && audio) {
                audio.pause();
                isPlaying = false;
                playButton.textContent = '🔊 Listen to Article';
                return;
            }

            if (audio && audio.src) {
                audio.play();
                isPlaying = true;
                playButton.textContent = '⏸️ Pause';
                return;
            }

            playButton.disabled = true;
            playButton.textContent = '⏳ Generating...';
            errorDiv.textContent = '';
            
            try {
                const response = await fetch(`${API_URL}/generate`, {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({
                        text: content.textContent,
                        options: {
                            provider: 'openai',
                            voice: voiceSelect.value,
                            speed: 1.0
                        }
                    })
                });

                if (!response.ok) {
                    throw new Error(`HTTP error! status: ${response.status}`);
                }

                const data = await response.json();
                
                audio = new Audio(`${API_URL}${data.url}`);
                
                audio.addEventListener('timeupdate', () => {
                    const percent = (audio.currentTime / audio.duration) * 100;
                    progressFill.style.width = `${percent}%`;
                });
                
                audio.addEventListener('ended', () => {
                    isPlaying = false;
                    playButton.textContent = '🔊 Listen to Article';
                    progressFill.style.width = '0%';
                });
                
                audio.addEventListener('error', () => {
                    errorDiv.textContent = '⚠️ Failed to load audio';
                    playButton.disabled = false;
                    playButton.textContent = '🔊 Listen to Article';
                });
                
                await audio.play();
                isPlaying = true;
                playButton.textContent = '⏸️ Pause';
                progressBar.style.display = 'block';
                
            } catch (error) {
                console.error('TTS Error:', error);
                errorDiv.textContent = `⚠️ ${error.message}`;
            } finally {
                playButton.disabled = false;
            }
        });
    </script>
</body>
</html>

Python Integration Example​

import requests
import json

class SupernalTTS:
    def __init__(self, api_url='https://tts.supernal.ai'):
        self.api_url = api_url
        self.api_v1 = f"{api_url}/api/v1"
    
    def generate(self, text, voice='nova', provider='openai', speed=1.0):
        """Generate speech from text"""
        response = requests.post(
            f"{self.api_v1}/generate",
            json={
                'text': text,
                'options': {
                    'provider': provider,
                    'voice': voice,
                    'speed': speed
                }
            }
        )
        response.raise_for_status()
        return response.json()
    
    def download_audio(self, audio_url, output_path):
        """Download audio file"""
        response = requests.get(f"{self.api_url}{audio_url}")
        response.raise_for_status()
        
        with open(output_path, 'wb') as f:
            f.write(response.content)
        
        return output_path
    
    def generate_to_file(self, text, output_path, **options):
        """Generate speech and save to file"""
        result = self.generate(text, **options)
        self.download_audio(result['audioUrl'], output_path)
        return result

# Usage
client = SupernalTTS()

# Generate and get URL
result = client.generate("Hello from Python!", voice='nova')
print(f"Audio URL: {result['audioUrl']}")
print(f"Duration: {result['duration']}s")

# Generate and save to file
client.generate_to_file(
    "Welcome to Supernal TTS!",
    "welcome.mp3",
    voice='fable',
    provider='openai'
)

# Batch processing
texts = [
    "First paragraph of content",
    "Second paragraph of content",
    "Third paragraph of content"
]

for i, text in enumerate(texts):
    print(f"Processing paragraph {i+1}...")
    client.generate_to_file(text, f"paragraph_{i+1}.mp3", voice='nova')
    print(f"Saved paragraph_{i+1}.mp3")

Discord Bot Integration​

const { Client, GatewayIntentBits } = require('discord.js');
const { joinVoiceChannel, createAudioPlayer, createAudioResource } = require('@discordjs/voice');
const fetch = require('node-fetch');

const TTS_API_URL = 'https://tts.supernal.ai/api/v1';

const client = new Client({
    intents: [
        GatewayIntentBits.Guilds,
        GatewayIntentBits.GuildMessages,
        GatewayIntentBits.MessageContent,
        GatewayIntentBits.GuildVoiceStates
    ]
});

client.on('messageCreate', async (message) => {
    if (message.content.startsWith('!tts ')) {
        const text = message.content.slice(5);
        
        try {
            // Generate audio
            const response = await fetch(`${TTS_API_URL}/generate`, {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({
                    text,
                    options: {
                        provider: 'cartesia', // Low latency for real-time
                        voice: 'confident-british-man'
                    }
                })
            });
            
            const data = await response.json();
            
            // Join voice channel and play
            const voiceChannel = message.member.voice.channel;
            if (voiceChannel) {
                const connection = joinVoiceChannel({
                    channelId: voiceChannel.id,
                    guildId: message.guild.id,
                    adapterCreator: message.guild.voiceAdapterCreator,
                });
                
                const player = createAudioPlayer();
                const resource = createAudioResource(`${TTS_API_URL.replace('/api/v1', '')}${data.audioUrl}`);
                
                player.play(resource);
                connection.subscribe(player);
                
                message.reply('🔊 Playing audio in voice channel!');
            } else {
                message.reply('You need to be in a voice channel!');
            }
            
        } catch (error) {
            console.error('TTS Error:', error);
            message.reply('Sorry, I couldn\'t generate that audio.');
        }
    }
});

client.login('YOUR_BOT_TOKEN');

Batch Processing Script​

const fs = require('fs');
const path = require('path');
const fetch = require('node-fetch');

const TTS_API_URL = 'https://tts.supernal.ai/api/v1';

class BatchTTSProcessor {
    constructor(options = {}) {
        this.apiUrl = options.apiUrl || TTS_API_URL;
        this.provider = options.provider || 'openai';
        this.voice = options.voice || 'fable';
        this.outputDir = options.outputDir || './output';
        this.processed = 0;
        this.errors = 0;
    }
    
    async processTextFiles(inputDir) {
        // Create output directory if it doesn't exist
        if (!fs.existsSync(this.outputDir)) {
            fs.mkdirSync(this.outputDir, { recursive: true });
        }
        
        const files = fs.readdirSync(inputDir)
            .filter(file => file.endsWith('.txt'));
        
        console.log(`Found ${files.length} text files to process\n`);
        
        for (const file of files) {
            await this.processFile(path.join(inputDir, file));
        }
        
        console.log(`\nProcessing complete:`);
        console.log(`- Processed: ${this.processed}`);
        console.log(`- Errors: ${this.errors}`);
    }
    
    async processFile(filePath) {
        const filename = path.basename(filePath, '.txt');
        const outputPath = path.join(this.outputDir, `${filename}.mp3`);
        
        // Skip if already processed
        if (fs.existsSync(outputPath)) {
            console.log(`⏭️  Skipping ${filename} (already exists)`);
            return;
        }
        
        try {
            const text = fs.readFileSync(filePath, 'utf8');
            console.log(`🎙️  Processing ${filename}... (${text.length} chars)`);
            
            const response = await fetch(`${this.apiUrl}/generate`, {
                method: 'POST',
                headers: { 'Content-Type': 'application/json' },
                body: JSON.stringify({
                    text,
                    options: {
                        provider: this.provider,
                        voice: this.voice,
                        quality: 'high'
                    }
                })
            });
            
            const data = await response.json();
            
            // Download audio file
            const audioResponse = await fetch(`${this.apiUrl.replace('/api/v1', '')}${data.audioUrl}`);
            const audioBuffer = await audioResponse.buffer();
            
            fs.writeFileSync(outputPath, audioBuffer);
            
            console.log(`✅ Generated ${filename}.mp3 (${data.duration}s, $${data.cost.toFixed(4)})`);
            this.processed++;
            
        } catch (error) {
            console.error(`❌ Failed to process ${filename}:`, error.message);
            this.errors++;
        }
    }
}

// Usage
const processor = new BatchTTSProcessor({
    apiUrl: 'https://tts.supernal.ai/api/v1',
    provider: 'openai',
    voice: 'fable',
    outputDir: './audio-output'
});

processor.processTextFiles('./text-input');

Run with:

node batch-processor.js

🎯 Common Use Case Patterns​

Blog Audio Generation with Caching​

class BlogAudioManager {
    constructor(apiUrl) {
        this.apiUrl = apiUrl;
        this.cache = new Map();
    }
    
    async generateBlogAudio(blogPost) {
        const cacheKey = blogPost.id;
        
        // Check cache first
        if (this.cache.has(cacheKey)) {
            return this.cache.get(cacheKey);
        }
        
        // Extract and clean content
        const content = this.extractContent(blogPost);
        
        // Split into manageable chunks (API limits)
        const chunks = this.splitIntoChunks(content, 4000);
        
        // Generate audio for each chunk
        const audioSegments = await Promise.all(
            chunks.map((chunk, index) => this.generateChunkAudio(chunk, index))
        );
        
        const result = {
            blogId: blogPost.id,
            totalDuration: audioSegments.reduce((sum, seg) => sum + seg.duration, 0),
            segments: audioSegments,
            generatedAt: new Date().toISOString()
        };
        
        this.cache.set(cacheKey, result);
        return result;
    }
    
    extractContent(blogPost) {
        let content = blogPost.content
            .replace(/<[^>]*>/g, '') // Remove HTML tags
            .replace(/\s+/g, ' ')    // Normalize whitespace
            .trim();
            
        content = `${blogPost.title}. By ${blogPost.author}. ${content}`;
        return content;
    }
    
    splitIntoChunks(text, maxLength) {
        const chunks = [];
        const sentences = text.split(/[.!?]+/);
        let currentChunk = '';
        
        for (const sentence of sentences) {
            if (currentChunk.length + sentence.length > maxLength) {
                if (currentChunk) {
                    chunks.push(currentChunk.trim());
                    currentChunk = '';
                }
            }
            currentChunk += sentence + '. ';
        }
        
        if (currentChunk) {
            chunks.push(currentChunk.trim());
        }
        
        return chunks;
    }
    
    async generateChunkAudio(text, index) {
        const response = await fetch(`${this.apiUrl}/api/v1/generate`, {
            method: 'POST',
            headers: { 'Content-Type': 'application/json' },
            body: JSON.stringify({
                text,
                options: {
                    provider: 'openai',
                    voice: 'fable',
                    quality: 'high'
                }
            })
        });
        
        return await response.json();
    }
}

E-Learning Platform with Pre-loading​

class LessonAudioPlayer {
    constructor(apiUrl) {
        this.apiUrl = apiUrl;
        this.audioCache = new Map();
    }
    
    async loadLesson(lessonId, segments) {
        console.log(`Loading audio for lesson ${lessonId}...`);
        
        // Pre-generate audio for all segments
        await this.preGenerateAudio(segments);
        
        console.log(`Lesson ${lessonId} ready to play`);
    }
    
    async preGenerateAudio(segments) {
        const promises = segments.map(async (segment) => {
            if (this.audioCache.has(segment.id)) return;
            
            try {
                const response = await fetch(`${this.apiUrl}/api/v1/generate`, {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify({
                        text: segment.content,
                        options: {
                            provider: 'openai',
                            voice: 'fable',
                            speed: 0.9 // Slightly slower for learning
                        }
                    })
                });
                
                const data = await response.json();
                this.audioCache.set(segment.id, data.audioUrl);
            } catch (error) {
                console.error(`Failed to generate audio for segment ${segment.id}`);
            }
        });
        
        await Promise.all(promises);
    }
    
    async playSegment(segmentId) {
        const audioUrl = this.audioCache.get(segmentId);
        if (!audioUrl) {
            throw new Error('Audio not available for this segment');
        }
        
        const audio = new Audio(`${this.apiUrl.replace('/api/v1', '')}${audioUrl}`);
        
        return new Promise((resolve) => {
            audio.onended = resolve;
            audio.play();
        });
    }
    
    async playFullLesson(segments) {
        for (const segment of segments) {
            await this.playSegment(segment.id);
            
            // Pause between segments
            await new Promise(resolve => setTimeout(resolve, 1000));
        }
    }
}

🚀 Quick Start Commands​

# Test with mock provider (no API key needed)
curl -X POST https://tts.supernal.ai/api/v1/generate \
  -H "Content-Type: 'application/json" \
  -d '{"text": "Hello world!", "options": {"provider": "mock"}}'

# Test with OpenAI (requires API key on server)
curl -X POST https://tts.supernal.ai/api/v1/generate \
  -H "Content-Type: application/json" \
  -d '{
    "text": "Welcome to Supernal TTS!",
    "options": {
      "provider": "openai",
      "voice": "nova"
    }
  }'

# Get audio file
curl https://tts.supernal.ai/api/v1/audio/{hash} -o output.mp3

# Check API health
curl https://tts.supernal.ai/api/v1/health

# List available providers
curl https://tts.supernal.ai/api/v1/providers

🔧 Local Development Setup​

# Clone repository
git clone https://github.com/supernalintelligence/supernal-nova.git
cd supernal-nova/families/supernal-tts

# Install dependencies
npm install

# Set up environment variables
cp .env.example .env
# Edit .env and add your API keys:
# OPENAI_API_KEY=sk-...
# CARTESIA_API_KEY=...
# AZURE_API_KEY=...

# Start server
npm run dev

# Server will be available at:
# http://localhost:3030

# Test the server
curl -X POST http://localhost:3030/api/v1/generate \
  -H "Content-Type: application/json" \
  -d '{"text": "Test", "options": {"provider": "mock"}}'

📝 Important Notes for LLMs​

  1. Always handle errors gracefully: API calls can fail for various reasons (rate limits, provider issues, network errors)

  2. Use caching: The API automatically caches identical text+voice combinations, reducing costs

  3. Provider selection:

    • Use mock for testing without API keys
    • Use openai for best quality (requires API key)
    • Use cartesia for lowest latency (requires API key)
    • Use azure for budget-friendly option (requires API key)

  4. Text length limits: Different providers have different limits. For long text, split into chunks

  5. Voice availability: Not all voices are available for all providers. Check /api/v1/providers endpoint

  6. Cost estimation: Use the /api/v1/estimate endpoint before generating to calculate costs

  7. Rate limiting: Respect rate limits (100 requests per minute by default)

  8. Audio format: Default is MP3, but WAV and OGG are also supported depending on provider

  9. Speed range: Valid speed range is 0.25 to 4.0 (provider-dependent)

  10. Browser compatibility: Audio playback works in all modern browsers. Use the HTML5 <audio> element