EchoFlow Image Generation (Nano Banana Pro)

Generate or edit images using EchoFlow API with Nano Banana Pro (Gemini 3 Pro Image). EchoFlow provides OpenAI-compatible access to Gemini's powerful image generation model.

Setup

1. Get your API key from EchoFlow: https://api.echoflow.cn/
2. Set environment variable: ECHOFLOW_API_KEY
3. Alternatively, set in OpenClaw config: skills."echoflow-image-gen".apiKey

Quick Start

Generate Image

uv run {baseDir}/scripts/generate_image.py --prompt "a serene mountain landscape at sunset" --filename "mountain.png"

Edit Image (Single)

uv run {baseDir}/scripts/generate_image.py --prompt "add a rainbow in the sky" --filename "edited.png" -i "/path/to/input.png"

Multi-Image Composition (up to 14 images)

uv run {baseDir}/scripts/generate_image.py --prompt "combine these into one scene" --filename "combined.png" -i img1.png -i img2.png -i img3.png

Parameters

Available Models

• gemini-3.1-flash-image-preview (default) - Faster, more available
• gemini-3-pro-image-preview - Higher quality, may have availability issues

Resolutions

• 1K (default) - Standard quality
• 2K - High quality
• 4K - Ultra high quality

Auto-detection: When editing images, the script auto-detects resolution from the largest input dimension:

• Input ≥3000px → 4K
• Input ≥1500px → 2K
• Input <1500px → 1K

Output

The script outputs:

• Image saved: - Location of saved image
• MEDIA: - Token for OpenClaw to auto-attach the image on supported chat providers

Examples

# Simple generation
uv run {baseDir}/scripts/generate_image.py -p "a cute cat wearing a hat" -f "cat.png"

# High resolution
uv run {baseDir}/scripts/generate_image.py -p "futuristic city" -f "city.png" -r 4K

# Edit single image
uv run {baseDir}/scripts/generate_image.py -p "add snow to the scene" -f "snowy.png" -i summer.png

# Compose multiple images
uv run {baseDir}/scripts/generate_image.py -p "create a collage of these photos" -f "collage.png" -i photo1.png -i photo2.png -i photo3.png -i photo4.png

# Use gemini-3-pro-image-preview model
uv run {baseDir}/scripts/generate_image.py -p "abstract art" -f "art.png" -m "gemini-3-pro-image-preview"

API Reference

For detailed API documentation, see echoflow_api.md.

Notes

• Use timestamp-based filenames for organization: 2024-03-28-18-30-landscape.png
• The script outputs a MEDIA: line for OpenClaw to auto-attach the image on supported providers
• Do not read the image back; report the saved path only
• For editing, ensure input images are in supported formats (PNG, JPEG, WebP)
• Nano Banana Pro supports up to 14 input images for composition
• If you get 429 errors, the upstream is saturated - wait a moment and retry
• EchoFlow API is OpenAI-compatible, so this skill works with any OpenAI-compatible endpoint by changing --api-base