@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