This is a guide for generating and editing images using the nanobanana CLI tool.
Nanobanana is a command-line interface for the Nano Banana image generation API, which uses Google's generative AI models.
Installation
If the nanobanana CLI is not already installed, install it using:
go install maragu.dev/nanobanana@latest
Prerequisites
The GOOGLE_API_KEY environment variable must be set, or a .env file with the key must be present in the working directory.
Generating images
To generate a single image:
nanobanana generate output.png "a beautiful sunset over mountains"
The output can be either a .png or .jpg file.
Using version 2 (preferred)
Always use the -v2 flag unless the user specifically requests the pro model. Version 2 offers improved quality and aspect ratio support:
nanobanana generate -v2 output.png "a beautiful sunset over mountains"
Using the pro model
To use the highest-quality pro model (only when explicitly requested):
nanobanana generate -pro output.png "a beautiful sunset over mountains"
Editing existing images
To edit or modify an existing image using a text prompt:
nanobanana generate -i input.png output.png "make the sky purple and add stars"
This is useful for making specific changes to existing images based on natural language instructions.
Tips for effective prompts
- Be specific and descriptive about what you want in the image
- Include details about style, colors, mood, composition, and subject matter
- For edits, clearly describe what should change while the rest remains the same
- You can reference art styles, artists, or specific visual aesthetics
Examples
Generate a logo:
nanobanana generate logo.png "minimalist tech company logo with geometric shapes in blue and white"
Create concept art:
nanobanana generate concept.png "futuristic city skyline at night with neon lights and flying vehicles, cyberpunk style"
Edit an existing photo:
nanobanana generate -i photo.png enhanced.png "enhance the colors and make it look like golden hour"