Agent skill · creative production · github
nano-banana-pro-openrouter
Generate or edit images via OpenRouter with the Gemini 3 Pro Image model. Use for prompt-only image generation, image edits, and multi-image compositing; supports 1K/2K/4K output.
Why this skill is useful
Adds executable scripts for image generation and editing using the OpenRouter API that are not commonly known or documented.
What it needs
Requires uv installed locally. Requires openrouter account access. About 1k tokens when loaded. Last updated 2026-08-07. 37,534 stars on the source repository.
What this skill does
Nano Banana Pro OpenRouter Overview Generate or edit images with OpenRouter using the google/gemini-3-pro-image-preview model. Support prompt-only generation, single-image edits, and multi-image composition. Prompt-only generation Edit a single image Compose multiple images Resolution Use --resolution with 1K, 2K, or 4K. Default is 1K if not specified. System prompt customization The skill reads an optional system prompt from assets/SYSTEMTEMPLATE. This allows you to customize the image generation behavior without modifying code. Behavior and constraints Accept up to 3 input images via repeated --input-image. --filename accepts relative paths (saves to current directory) or absolute paths. If multiple images are returned, append -1, -2, etc. to the filename. Print MEDIA: <path> for each saved image. Do not read images back into the response. Troubleshooting If the script exits non-zero, check stderr against these common blockers: Symptom Resolution --------- ------------ OPENROUTERAPIKEY is not set Ask the user to set it. PowerShell: $env:OPENROUTERAPIKEY = "sk-or-..." / bash: export OPENROUTERAPIKEY="sk-or-..." uv: command not found or not recognized macOS/Linux: <code>curl -LsSf https://astral.sh/uv/install.sh | sh</code>. Windows: <code>powershell -ExecutionPolicy ByPass -c "irm https://astral.sh/uv/install.ps1 | iex"</code>. Then restart the terminal. AuthenticationError / HTTP 401 Key is invalid or has no credits. Verify at <https://openrouter.ai/settings/keys>. For transient errors (HTTP 429, network timeouts), retry once after 30 seconds. Do not retry the same error more than twice — surface the issue to the user instead.
How to use it
Reference it in AdaL, Claude Code, Cursor or any coding agent — nothing to install:
@skills github/nano-banana-pro-openrouter