nb-cli

name	nb-cli
description	Generate and edit still images using the Nano Banana (Gemini) CLI tool. Use when Codex needs to create, edit, or create icons with `nb generate`, `nb edit`, or `nb icon`, especially for prompt-driven visual assets, marketing images, mockups, illustrations, and simple image revisions from the terminal.

nb-cli

Nano Banana CLI Tool — Generate and edit images with the power of Google Gemini models directly from your terminal.

The bundled still-image technique references were inspired by the film and photography vocabulary collected at https://grokfilm.app/.

Example trigger requests:

• Use $nb-cli to generate a 16:9 SaaS hero image with soft daylight and editorial composition
• Use $nb-cli to create a minimalist coffee cup icon for my app
• Use $nb-cli to edit hero.jpg and change only the background to a warm sunset gradient
• Use $nb-cli to generate a product mockup for a matte black bottle, centered three-quarter angle, soft studio light

Core Workflows

1. Image Generation

Turn prompts into visuals using nb generate <prompt>.

• Use -o, --output <path> for a specific path (otherwise generates a random 6-char .jpg filename).
• Use -s, --size <size> to set resolution (512 (default), 1k, 2k, 4k).
• Use -a, --aspect-ratio <ratio> for your desired format (e.g., 16:9, 21:9).
• Use -m, --model <model> to pick a model alias or ID. Use lite for gemini-3.1-flash-lite-image; Lite supports 1k output only.

2. Icon Generation

Create 1:1 square icons using nb icon <prompt>.

• Automatically prepends "High-quality minimalist icon for: " to your prompt.
• Defaults to 1:1 aspect ratio.

3. Image Editing

Modify existing images using nb edit <image_path> <prompt>.

• Describe the changes you want in the prompt.
• Optionally change the output size or aspect ratio.

Prompt Construction

• Treat this skill as a still-image skill. Use visual language that can be expressed in one image.
• Ignore film/video techniques that depend on motion, multi-shot sequencing, editing rhythm, sound, or camera movement.
• Prefer concise prompts with a clear subject, scene, composition, lighting, and constraints.
• For edits, state invariants explicitly: change only X; keep Y unchanged.
• If the task is an icon, keep prompts simple, silhouette-friendly, and background-light unless the user asks otherwise.

Detailed Reference

• Aspect Ratios: See ratios.md for all supported formats.
• Example Prompts: See examples.md for common use cases.
• Still Camera / Framing: See still-camera-framing.md for single-image shot and angle vocabulary.
• Still Lighting: See still-lighting.md for lighting setups and mood cues.
• Still Composition: See still-composition.md for layout, depth, and hierarchy language.
• Still Look / Style: See still-look-and-style.md for optical finish, grade, and single-frame visual styles.

Usage Guide

When a user asks to generate or edit an image, follow these steps:

1. Identify the command (generate, icon, or edit).
2. Extract parameters (prompt, output path, size, aspect ratio, model).
3. Build or refine the prompt using only still-image vocabulary that materially helps.
4. If no output path is given, note that the tool will generate a random .jpg filename.
5. Execute the command in the repo shell.

Prompt Shape

Use compact prompt structure when the request is underspecified:

• Subject: what should be visible
• Scene/background: where it is
• Composition/framing: shot size, viewpoint, layout
• Lighting/mood: quality of light and atmosphere
• Style/finish: illustration, photo, render, noir, CRT, etc.
• Constraints: what to avoid or preserve

Only add the lines that help. If the user already gave a precise prompt, normalize it instead of expanding it.

Example

User: "Generate a wide cinematic 2k image of a futuristic city" Action: nb generate "A futuristic city" -a 21:9 -s 2k