🎙️ ComfyUI-Gemini_TTS

A powerful ComfyUI custom node that brings Google's Gemini TTS capabilities directly to your workflow. Generate high-quality speech with 30+ voices supporting both free and paid tiers.

✨ Features

• 30+ Premium Voices: Male and female voices with unique characteristics
• Dual Tier Support: Free tier with generous limits + Paid tier for production use
• Smart Fallback: Automatic model switching when quotas are reached
• Voice Characteristics: Detailed voice info with personality descriptions
• Flexible Configuration: Environment variables, node parameters, or config file
• Robust Error Handling: Clear error messages and automatic retry logic
• Real-time Pricing: Cost estimates for paid tier usage

🚀 Quick Start

1. Installation

1. Clone or download this repository to your ComfyUI custom nodes folder:

   cd ComfyUI/custom_nodes/
   git clone https://github.com/ShmuelRonen/ComfyUI-Gemini_TTS.git
   

2. Install dependencies:

   cd gemini-tts-node
   pip install google-generativeai requests torch torchaudio numpy
   

3. Restart ComfyUI - The node will appear as "🎙️ Gemini Text-to-Speech"

2. Get Your API Key

Free Tier (Recommended to Start)

1. Go to Google AI Studio
2. Sign in with your Google account
3. Click "Get API Key" → "Create API Key"
4. Select "Create API key in new project"
5. Copy your API key (starts with AIza...)

Paid Tier (For Production)

See the Paid Tier Setup section below.

3. Configure the Node

Option A: Environment Variable (Recommended)

export GEMINI_API_KEY="your_api_key_here"

Option B: Direct Input

• Enter your API key directly in the node's api_key field
• The node will save it automatically for future use

🎭 Available Voices

Female Voices (14 total)

• Aoede - Breezy and natural
• Kore - Firm and confident
• Leda - Youthful and energetic
• Zephyr - Bright and cheerful
• Autonoe - Bright and optimistic
• Callirhoe - Easy-going and relaxed
• Despina - Smooth and flowing
• Erinome - Clear and precise
• Gacrux - Mature and experienced
• Laomedeia - Upbeat and lively
• Pulcherrima - Forward and expressive
• Sulafat - Warm and welcoming
• Vindemiatrix - Gentle and kind
• Achernar - Soft and gentle

Male Voices (16 total)

• Puck - Upbeat and energetic (default)
• Charon - Informative and clear
• Fenrir - Excitable and dynamic
• Orus - Firm and decisive
• Achird - Friendly and approachable
• Algenib - Gravelly texture
• Algieba - Smooth and pleasant
• Alnilam - Firm and strong
• Enceladus - Breathy and soft
• Iapetus - Clear and articulate
• Rasalgethi - Informative and professional
• Sadachbia - Lively and animated
• Sadaltager - Knowledgeable and authoritative
• Schedar - Even and balanced
• Umbriel - Easy-going and calm
• Zubenelgenubi - Casual and conversational

⚙️ Node Parameters

Required Parameters

• prompt: Text to convert to speech (supports "Say:" prefix)
• tts_model: Choose between:
  • gemini-2.5-pro-preview-tts (Higher quality, slower)
  • gemini-2.5-flash-preview-tts (Faster, good quality)
• voice: Select from 30+ available voices
• temperature: Control creativity (0.0-2.0, default: 1.0)

Optional Parameters

• api_key: Enter API key directly (auto-saved)
• auto_fallback_to_flash: Auto-switch to Flash if Pro is rate-limited
• retry_delay: Wait time between retries (10-120 seconds)
• use_paid_tier: Enable paid billing for higher quotas
• billing_project_id: Google Cloud project ID for billing
• aggressive_retry: More retry attempts for better reliability
• show_voice_info: Display voice characteristics in output

💰 Paid Tier Setup

Why Upgrade to Paid Tier?

| Feature | Free Tier | Paid Tier | |---------|-----------|-----------| | Quota Limits | Low (good for testing) | High (production ready) | | Rate Limits | Restrictive | Generous | | Priority Access | Standard | Premium | | Cost | Free | ~$0.001-0.02 per request |

Step-by-Step Paid Setup

1. Create Google Cloud Project

1. Go to Google Cloud Console
2. Click "New Project" or select existing project
3. Enter project name (e.g., "my-gemini-tts")
4. Note your Project ID (not the name - this is important!)

2. Enable Billing

1. In Google Cloud Console, go to Billing
2. Click "Link a billing account" or "Enable billing"
3. Add a payment method (credit card required)
4. Verify billing is active on your project

3. Enable the Gemini API

1. Go to APIs & Services > Library
2. Search for "Generative Language API"
3. Click "Enable" on the Generative Language API
4. Wait for activation (usually instant)

4. Create API Key

1. Go to APIs & Services > Credentials
2. Click "Create Credentials" > "API Key"
3. Copy your new API key
4. Optional: Restrict the key to "Generative Language API" for security

5. Configure the Node

Set these parameters in the node:

• use_paid_tier: True
• billing_project_id: Your Project ID from step 1
• api_key: Your API key from step 4

💵 Pricing Information

Gemini 2.5 Pro TTS:

• Input: $1.00 per 1M tokens
• Output: $20.00 per 1M tokens
• ~$0.01-0.02 per typical request

Gemini 2.5 Flash TTS:

• Input: $0.50 per 1M tokens
• Output: $10.00 per 1M tokens
• ~$0.005-0.01 per typical request

Typical 20-word sentence costs less than $0.02

🔧 Troubleshooting

Common Issues

"API key not valid" Error

• Solution: Verify your API key starts with AIza and is ~39 characters
• Check: API key hasn't expired or been deleted
• Verify: You're using the correct key from Google AI Studio or Cloud Console

"Rate limit exceeded" Error

• Free Tier: Wait 60 seconds or try Flash model
• Solution: Enable paid tier for higher quotas
• Temporary: Use auto_fallback_to_flash = True

"Billing project not found" Error

• Check: Use Project ID, not project name
• Verify: Project exists and billing is enabled
• Confirm: API key belongs to the same project

"Permission denied" Error

• Verify: Generative Language API is enabled
• Check: API key has proper permissions
• Ensure: Billing is active if using paid tier

Configuration Files

The node creates a config.json file to save your settings:

{
    "GEMINI_API_KEY": "your_key_here",
    "use_paid_tier": true,
    "billing_project_id": "your-project-id"
}

Debug Information

Enable debugging by checking console output:

• Green ✅: Successful operations
• Yellow ⚠️: Warnings and fallbacks
• Red ❌: Errors requiring attention

📝 Usage Examples

Basic Text-to-Speech

Prompt: "Hello, welcome to our presentation today."
Model: gemini-2.5-flash-preview-tts
Voice: [F] Zephyr
Temperature: 1.0

Expressive Reading

Prompt: "Say: Once upon a time, in a land far, far away..."
Model: gemini-2.5-pro-preview-tts  
Voice: [M] Charon
Temperature: 1.5
Show Voice Info: True

Production Setup

Use Paid Tier: True
Billing Project ID: my-production-project-123
Aggressive Retry: True
Model: gemini-2.5-pro-preview-tts

🛡️ Security Best Practices

1. Protect Your API Key: Never commit API keys to version control
2. Use Environment Variables: Set GEMINI_API_KEY in your environment
3. Restrict API Keys: Limit to specific APIs in Google Cloud Console
4. Monitor Usage: Check Google Cloud billing dashboard regularly
5. Project Isolation: Use separate projects for development vs production

🔄 Updates and Compatibility

• ComfyUI: Compatible with latest versions
• Python: Requires Python 3.8+
• Dependencies: Auto-updated through pip
• Voice Library: Automatically synced with Google's latest voices

📞 Support

Common Solutions

1. Restart ComfyUI after installation or configuration changes
2. Check Console Output for detailed error messages
3. Verify API Key Format (should start with AIza)
4. Confirm Project Settings in Google Cloud Console

Getting Help

• Check the troubleshooting section above
• Review console output for specific error messages
• Verify your Google Cloud project configuration
• Ensure billing is properly enabled for paid tier

📜 License

This project is provided as-is for educational and commercial use. Google Gemini API usage is subject to Google's terms of service and pricing.

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🎉 Ready to generate amazing speech with Gemini TTS!

Last updated: May 2025