Nano Banana MCP Server

A local stdio MCP server for Gemini-powered image generation.

Features

• Simple MCP to generate images with Google's Gemini image models

• Save generated output to local disk as JPEG

• Return both user-facing content and structured tool output for clients

• Run locally via stdio (no HTTP transport in this project)

Related MCP server: nano-banana-mcp

Prerequisites

• Node.js 20+

• Gemini API key from Google AI Studio

Install

git clone https://github.com/priorwave/nano_banana_mcp_server/
cd nano-banana-mcp
npm install
npm run build

Configuration

Set an API key in your shell profile:

export GEMINI_API_KEY="your-key-here"
# GOOGLE_API_KEY is also supported

Optional model override:

export GEMINI_IMAGE_MODEL="gemini-2.5-flash-image"

Configure your MCP client to run this server locally via stdio:

{
  "mcpServers": {
    "nano-banana": {
      "command": "node",
      "args": ["/absolute/path/to/nano_banana_mcp_server/dist/index.js"],
      "env": {
        "GEMINI_API_KEY": "${GEMINI_API_KEY}"
      }
    }
  }
}

Tool: generate_image

The tool returns:

• Text status content

• Image content

• Structured output with file_path, mime_type, model, and optional text

Development

• Build: npm run build

• Start: npm start

• Test: npm test