---
name: nano-banana-pro-openrouter-d3a5f0df4212
description: Generate images with Nano Banana Pro via OpenRouter. Use when the user asks for image generation, mentions Nano Banana Pro, Gemini 3 Pro Image, or OpenRouter image generation.
---

# 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:
```bash
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 `~/.openclaw/workspace/outputs/nano-banana-pro-openrouter`
- 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
  - `sh ~/.openclaw/workspace/skills/nano-banana-pro-openrouter/scripts/generate_image.sh --prompt "<final prompt>" --filename auto --resolution 4K`

## 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)
2. OPENROUTER_API_KEY environment variable

The API base URL must be set via OPENROUTER_BASE_URL. 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)
- `command -v curl` (must exist)
- `command -v base64` (must exist)

Common failures:
- `Error: No API key provided.` -> read .env and retry with --api-key; if still failing, ask the user to set OPENROUTER_API_KEY
- `Error: No API base URL provided.` -> ensure OPENROUTER_BASE_URL is set to a full chat completions endpoint
- `Error loading input image:` -> 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

## Filename Generation

Generate filenames with the pattern: `yyyy-mm-dd-hh-mm-ss-name.png`

Format: `{timestamp}-{descriptive-name}.png`
- Timestamp: Current date/time in format `yyyy-mm-dd-hh-mm-ss` (24-hour format)
- Name: Descriptive lowercase text with hyphens
- Keep the descriptive part concise (1-5 words typically)
- Use context from the user's prompt or conversation
- If unclear, use `image`

Examples:
- Prompt "A serene Japanese garden" -> `2025-11-23-14-23-05-japanese-garden.png`
- Prompt "sunset over mountains" -> `2025-11-23-15-30-12-sunset-mountains.png`
- Prompt "create an image of a robot" -> `2025-11-23-16-45-33-robot.png`
- Unclear context -> `2025-11-23-17-12-48-image.png`

Tip: To avoid incorrect timestamps, pass `--filename auto` and let the script
generate the filename using the system clock.

## Image Editing (Not Supported in Shell Version)

The shell script only supports generating new images. Editing an input image is not available in this version.

## Prompt Handling

For generation: pass the user's image description as-is to --prompt. Only rework if clearly insufficient.

## Prompt Templates (high hit-rate)

Use templates when the user is vague or when edits must be precise.

Generation template:
- "Create an image of: <subject>. Style: <style>. Composition: <camera/shot>. Lighting: <lighting>. Background: <background>. Color palette: <palette>. Avoid: <list>."

## Output

- Saves PNG to `~/.openclaw/workspace/outputs/nano-banana-pro-openrouter`
- If `--filename` includes a path, only the basename is used
- Script outputs the full path to the generated image
- Script also outputs `MEDIA_URL=file:///absolute/path` for each image

### Show the image in the reply

- Use the MEDIA_URL value to attach the image in the model response
- In OpenClaw, prefer sending a message with mediaUrl set to that file:// URL
- Also include the file path in text for reference

## Examples

Generate new image:
```bash
sh ~/.openclaw/workspace/skills/nano-banana-pro-openrouter/scripts/generate_image.sh --prompt "A serene Japanese garden with cherry blossoms" --filename auto --resolution 4K
```


---
Source attribution: kbarbel640-del
Original project: https://github.com/kbarbel640-del/skills/blob/e7e336ac628c3e3bd771aff1aaa469c93778f94a/skills/duffycoder/nano-banana-pro-openrouter/SKILL.md
License: MIT
License information: https://opensource.org/license/mit
Original upstream instructions; downloaded from Mega AI Hub.

## Upstream license notice

MIT License

Copyright (c) 2026 clawdbot

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.



# Mega AI Hub resource metadata

Creator / publisher: kbarbel640-del
Original project: https://github.com/kbarbel640-del/skills/blob/e7e336ac628c3e3bd771aff1aaa469c93778f94a/skills/duffycoder/nano-banana-pro-openrouter/SKILL.md
Attribution basis: Source repository record

Fields of work: Design, Marketing
Roles: Content Marketer, Graphic Designer, UX Designer
Specialties: Design
Tools: OpenAI API, Nano Banana Pro, Openrouter
Country applicability: Country not specified
Classification basis: Source catalog labels
Instruction SHA-256: bec97dca63f1b9cc17e476ab2a64fb5ebba2e822a54e4f4faafd9d2932ca6912