@maheidem/nanobanana-mcp

MCP server for Google's Nano Banana image generation models (Gemini). Generate and edit images via natural language from Claude Code or any MCP client.

Features

• Text-to-image generation with configurable model, aspect ratio, and resolution (up to 4K)
• Image editing via natural language — add/remove elements, style transfer, inpainting
• Iterative refinement — keep editing the last generated image
• 3 model tiers — Flash (cheap), Pro (studio-quality), Flash 2 (best value)
• File paths only — no base64 in responses, prevents context window overflow
• Persistent model preference — choose once, used everywhere

Models

Model	ID	Status	Max Resolution	Price/Image
Nano Banana	gemini-2.5-flash-image	GA	1K	$0.039
Nano Banana Pro	gemini-3-pro-image-preview	Preview	4K	$0.134–$0.24
Nano Banana 2	gemini-3.1-flash-image-preview	Preview	4K	$0.045–$0.151

Prerequisites

• Node.js >= 18
• A Google AI API key with billing enabled (no free tier for image generation)
• Get your key at Google AI Studio

Install

Claude Code (recommended)

claude mcp add nano-banana -e GEMINI_API_KEY=your-key -- npx --yes @maheidem/nanobanana-mcp

Manual .mcp.json

{
  "mcpServers": {
    "nano-banana": {
      "command": "npx",
      "args": ["@maheidem/nanobanana-mcp"],
      "env": {
        "GEMINI_API_KEY": "your-key"
      }
    }
  }
}

Tools

nb_generate_image

Generate a new image from a text prompt.

Parameter	Required	Description
prompt	Yes	Text description of the image
model	No	Model ID (uses saved preference)
aspectRatio	No	e.g. 16:9, 1:1, 9:16
imageSize	No	512, 1K, 2K, or 4K
outputDir	No	Save directory (default: NB_OUTPUT_DIR or cwd)

nb_edit_image

Edit an existing image with natural language instructions.

Parameter	Required	Description
imagePath	Yes	Path to the source image
prompt	Yes	Edit instructions
referenceImagePaths	No	Reference images for style transfer
model	No	Model ID
aspectRatio	No	Output aspect ratio
imageSize	No	Output resolution
outputDir	No	Save directory

nb_continue_editing

Continue editing the last generated/edited image.

Parameter	Required	Description
prompt	Yes	New edit instructions
model	No	Model ID
imageSize	No	Output resolution
outputDir	No	Save directory

nb_get_last_image

Get metadata about the last generated/edited image. No API call.

nb_list_models

List available models and set a preferred model (persisted to disk).

Parameter	Required	Description
setModel	No	Model ID to save as default

Environment Variables

Variable	Required	Description
GEMINI_API_KEY	Yes	Google AI API key (or GOOGLE_API_KEY)
NB_OUTPUT_DIR	No	Default output directory for generated images

License

MIT