A SillyTavern extension for image generation using Google's Nano Banana Pro (Gemini 3 Pro Image) and Nano Banana (Gemini 2.5 Flash Image) models.
- Message Generation Button - Wand icon (✨) on each message to generate an image from that message's content
- Character Context - Optionally includes character and user descriptions in prompts
- Multiple Aspect Ratios - 1:1, 3:4, 4:3, 9:16, 16:9
- Gallery - View and manage generated images
- Slash Commands -
/vimg <prompt>for quick generation
| Model | Codename | Description | Best For |
|---|---|---|---|
| Nano Banana Pro | gemini-3-pro-image-preview |
Highest quality, advanced text rendering, up to 14 reference inputs | Complex compositions, text in images, professional work |
| Nano Banana | gemini-2.5-flash-preview-image-generation |
Fast, good quality | Quick edits, casual creation |
| Type | Price |
|---|---|
| Input (text) | $1.25 / 1M tokens |
| Input (image) | $0.0032 / image |
| Output (text) | $10.00 / 1M tokens |
| Output (image) | $0.04 / image |
| Type | Price |
|---|---|
| Input (text) | $0.15 / 1M tokens |
| Input (image) | $0.0004 / image |
| Output (text) | $0.60 / 1M tokens |
| Output (image) | $0.02 / image |
Prices as of December 2025. Check Google AI Pricing for current rates.
- SillyTavern (latest staging branch)
- Google AI Studio API key OR Vertex AI Express Mode configured
- Paid tier required for image generation
- Open SillyTavern Extensions panel
- Click "Install Extension"
- Paste:
https://github.com/delidgi/vertex - Configure your Google AI / Vertex AI credentials in SillyTavern
- Open a chat with a character
- Click "..." menu on any message
- Click the wand icon (✨) to generate an image
- Open extension settings (Vertex Image Generation 🎨)
- Click "Generate Image" to create from the last message
/vimg a beautiful sunset over mountains
/verteximagine portrait of a fantasy warrior
/verteximg scenic landscape with castle
| Setting | Description |
|---|---|
| Model | Nano Banana Pro (best quality) or Nano Banana (faster) |
| Aspect Ratio | 1:1, 3:4, 4:3, 9:16, or 16:9 |
| Include Descriptions | Add character descriptions to the prompt |
| System Instruction | Custom instructions for image generation |
- Ensure you have a paid Google AI Studio or Vertex AI account
- Free tier does not support image generation
- Try a different prompt
- Some content may be blocked by safety filters
- Check browser console (F12) for detailed errors
- Verify your API key has image generation permissions
Nano Banana Pro (Gemini 3 Pro Image) is Google DeepMind's state-of-the-art image generation model, announced November 2025. Key features:
- High-fidelity image generation with reasoning
- Accurate text rendering in multiple languages
- Character consistency with up to 14 reference inputs
- Complex multi-turn editing
- Search grounding for real-time information
Nano Banana (Gemini 2.5 Flash Image) is the faster, more affordable option for casual creation.
- Based on context-image-generation by Elouann
- Modified for Nano Banana Pro support
- Created for use with SillyTavern
This project is released into the public domain under The Unlicense.