Nano Banana Pro Image Generation

Generate new images using OpenRouter's Nano Banana Pro (Gemini 3 Pro Image Preview).

Usage

Run the script using an absolute path (do NOT cd to the skill directory first):

Generate new image:

sh ~/.openclaw/workspace/skills/nano-banana-pro-openrouter/scripts/generate_image.sh --prompt "your image description" [--filename "output-name.png" | --filename auto] [--resolution 1K|2K|4K] [--api-key KEY]

Note: the shell version currently supports generation only (no input image editing).

Important:

- Images are always saved under INLINECODE0
If --filename contains a path, only the basename is used

Default Workflow (draft -> iterate -> final)

Goal: fast iteration without burning time on 4K until the prompt is correct.

- Draft (1K): quick feedback loop

sh ~/.openclaw/workspace/skills/nano-banana-pro-openrouter/scripts/generate_image.sh --prompt "<draft prompt>" --filename auto --resolution 1K

- Iterate: adjust prompt in small diffs; keep filename new per run
Final (4K): only when prompt is locked

- INLINECODE3

Resolution Options

The Gemini 3 Pro Image API supports three resolutions (uppercase K required):

- 1K (default) - ~1024px resolution
2K - ~2048px resolution
4K - ~4096px resolution

Map user requests to API parameters:

- No mention of resolution -> 1K
"low resolution", "1080", "1080p", "1K" -> 1K
"2K", "2048", "normal", "medium resolution" -> 2K
"high resolution", "high-res", "hi-res", "4K", "ultra" -> 4K

API Key and Base URL

The script checks for the API key in this order:

1. --api-key argument (use if user provided a key in chat)
OPENROUTERAPIKEY environment variable

The API base URL must be set via OPENROUTERBASEURL. Use the full chat
completions endpoint (for OpenRouter: https://openrouter.ai/api/v1/chat/completions).

The script also loads .env files automatically (if present):

- Current working directory .env
Skill directory .env

Important: If a .env file exists, do not ask the user for the key up front.
Just run the script and only ask if it errors with "No API key provided."

OpenClaw Chat Execution Rules

- OpenClaw does NOT auto-source the skill .env file
If ~/.openclaw/workspace/skills/nano-banana-pro-openrouter/.env exists:

1. Use the read tool to read .env 2. Extract OPENROUTER_API_KEY and OPENROUTER_BASE_URL 3. Always pass the key via --api-key when running the script

- Only ask the user if .env is missing or the key cannot be read
If the user asks for a timestamped filename, prefer --filename auto (do not handwrite dates)

If neither is available, the script exits with an error message.

Preflight and Common Failures (fast fixes)

Preflight:

- command -v sh (must exist)
INLINECODE13 (must exist)
INLINECODE14 (must exist)

Common failures:

- Error: No API key provided. -> read .env and retry with --api-key; if still failing, ask the user to set OPENROUTERAPIKEY
INLINECODE16 -> ensure OPENROUTERBASEURL is set to a full chat completions endpoint
INLINECODE17 -> wrong path or unreadable file; verify --input-image points to a real image
"quota/permission/403" style API errors -> wrong key, no access, or quota exceeded; try a different key/account