# KOF Nano Banana MCP Server π
MCP server for Gemini native image generation (Nano Banana). Part of the [KeepOnFirst Agentic Workflow](https://github.com/keeponfirst/keeponfirst-agentic-workflow-starter).
English | [ηΉι«δΈζ](README_zh-TW.md)
## β οΈ Important: Billing Required
**Note: The Gemini API Free Tier does NOT support image generation models.**
To use this MCP server, you must provide an API key from a Google Cloud project with billing enabled.
## Features
- **Generate images** using Gemini 2.5 Flash Image or Gemini 3 Pro Image
- **Process queue** of prompt files with validation and dry-run support
- **YAML frontmatter** support for prompt configuration
- **Cross-IDE compatible** - works with any MCP-enabled client
## Installation
### Option 1: Use via npx (Recommended)
If you have published this package or use it locally:
```json
{
"mcpServers": {
"nanobanana": {
"command": "npx",
"args": ["-y", "@keeponfirst/kof-nanobanana-mcp"],
"env": {
"GEMINI_API_KEY": "your-api-key-here"
}
}
}
}
```
### Option 2: Local Development
```bash
cd kof-nanobanana-mcp
npm install
npm run build
```
Then configure absolute path in your MCP config (see Configuration section).
## Configuration
### 1. Get a Gemini API Key
1. Go to [Google AI Studio](https://aistudio.google.com/apikey)
2. Create an API key
3. **IMPORTANT**: Ensure your project has billing enabled. These models are paid-only.
### 2. Add to MCP Config
Add to your MCP configuration file (e.g., `~/.gemini/antigravity/mcp_config.json`):
```json
{
"servers": {
"nanobanana": {
"command": "node",
"args": ["/path/to/kof-nanobanana-mcp/dist/index.js"],
"env": {
"GEMINI_API_KEY": "your-api-key-here"
}
}
}
}
```
## Tools
### `nanobanana_generate_image`
Generate a single image.
**Parameters:**
| Name | Type | Required | Description |
|------|------|----------|-------------|
| `prompt` | string | β
| Image description (10-5000 chars) |
| `output_path` | string | β
| Path to save the image |
| `model` | string | β | `gemini-2.5-flash-image` (default) or `gemini-3-pro-image-preview` |
| `aspect_ratio` | string | β | `1:1`, `16:9`, `9:16`, `4:3`, `3:4` |
| `overwrite` | boolean | β | Overwrite existing file (default: false) |
**Example:**
```json
{
"prompt": "A modern flat illustration of three AI robots working together on code",
"output_path": "assets/generated/workflow-hero.png",
"model": "gemini-2.5-flash-image",
"aspect_ratio": "16:9"
}
```
### `nanobanana_list_queue`
List and validate prompt files in the queue.
**Parameters:**
| Name | Type | Required | Description |
|------|------|----------|-------------|
| `queue_dir` | string | β | Queue directory (default: `nanobanana/queue`) |
| `validate` | boolean | β | Validate files (default: true) |
| `check_conflicts` | boolean | β | Check if outputs exist (default: true) |
### `nanobanana_process_queue`
Batch process all prompt files.
**Parameters:**
| Name | Type | Required | Description |
|------|------|----------|-------------|
| `queue_dir` | string | β | Queue directory (default: `nanobanana/queue`) |
| `validate_only` | boolean | β | Only validate, no generation |
| `dry_run` | boolean | β | Preview without API calls |
| `overwrite` | string | β | `skip`, `overwrite`, or `rename` |
## Prompt File Format
Create `.md` files in `nanobanana/queue/` with YAML frontmatter:
```markdown
---
output_path: assets/generated/workflow-hero.png
model: gemini-2.5-flash-image
aspect_ratio: 16:9
overwrite: false
---
# Workflow Hero Image
Create a modern, sleek hero illustration showing three AI agents
working together in a software development workflow.
## Style Guidelines
- Style: Flat illustration with gradients
- Color palette: Deep purple (#6B46C1) to blue (#3B82F6)
- Background: Subtle gradient
```
## Pricing Reference
| Model | Price per Image |
|-------|-----------------|
| Gemini 2.5 Flash Image | ~$0.039 (1024x1024) |
| Gemini 3 Pro Image (2K) | ~$0.134 |
| Gemini 3 Pro Image (4K) | ~$0.24 |
## License
MIT
