nano-banana-mcp

nano-banana-mcp is a free AI image generation server for Claude and other MCP clients. It uses the Nano Banana image model inside Google Flow through a Chrome browser window, requiring no API key, billing account, or per-image cost. It generates images at exact pixel sizes by cropping from Flow's native aspect ratios using saliency detection.

The server addresses the limitation that Flow generates only in five fixed aspect ratios (16:9, 4:3, 1:1, 3:4, 9:16), while real design work often needs specific dimensions like 1200x630 for Open Graph cards. It produces the exact requested size locally by cropping and scaling the native render, and can also upscale using Flow's own upscaler for 2K or 4K detail.

It supports reference images, batch generation of multiple prompts, and provides tools for listing the project library, downloading images, and upscaling. The server operates by driving the Flow web interface, intercepting network responses to reliably capture generated images, and includes a cost gate that aborts if the credit cost exceeds a configured maximum.