Image Gen

Image Generation Skill

This skill enables you to generate images using a variety of state-of-the-art AI models. It supports:

• Midjourney (via Legnext.ai) — Best for artistic, cinematic, and highly detailed images. Faster and more stable than other MJ providers.
• Flux 1.1 Pro (via fal.ai) — Best for photorealistic images and complex scenes.
• Flux Dev (via fal.ai) — Fast, high-quality generation for general use.
• Flux Schnell (via fal.ai) — Ultra-fast generation (<2s), great for quick drafts.
• SDXL Lightning (via fal.ai) — Fast Stable Diffusion XL, great for stylized art.
• Nano Banana Pro (via fal.ai fal-ai/nano-banana-pro) — Google Gemini-powered image generation and editing.
• Ideogram v3 (via fal.ai) — Best for images with text, logos, and typography.
• Recraft v3 (via fal.ai) — Best for vector-style, icon, and design assets.

Model Selection Guide

When the user does not specify a model, use this guide to pick the best one:

How to Use This Skill

Basic Usage

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

1. Understand the request: Identify the subject, style, and any specific requirements.
2. Select a model: Use the guide above, or honor the user's explicit model choice.
3. Enhance the prompt: Expand the user's prompt with relevant style, lighting, and quality descriptors appropriate for the chosen model.
4. Call the generation script: Use the exec tool to run the generation script.
5. Return the result: Present the image URL(s) to the user.

Calling the Generation Script

Use the exec tool to run the Node.js script at {baseDir}/generate.js:

node {baseDir}/generate.js \
  --model <model_id> \
  --prompt "<enhanced prompt>" \
  [--aspect-ratio <ratio>] \
  [--num-images <1-4>] \
  [--negative-prompt "<negative prompt>"]

Parameters:

• --model: One of midjourney, flux-pro, flux-dev, flux-schnell, sdxl, nano-banana, ideogram, recraft
• --prompt: The image generation prompt (required)
• --aspect-ratio: Output aspect ratio, e.g. 16:9, 1:1, 9:16, 4:3, 3:4 (default: 1:1)
• --num-images: Number of images to generate, 1-4 (default: 1, Midjourney always returns 4)
• --negative-prompt: Things to avoid in the image (not supported by Midjourney)
• --mode: Midjourney speed mode: turbo (default, 10-20s, requires Pro/Mega plan), fast (30-60s), relax (free but slow)

Example:

node {baseDir}/generate.js \
  --model flux-pro \
  --prompt "a majestic snow leopard on a mountain peak, golden hour lighting, photorealistic, 8k" \
  --aspect-ratio 16:9 \
  --num-images 1

Midjourney-Specific Notes

Midjourney is powered by Legnext.ai (faster and more stable than TTAPI). Turbo mode is enabled by default (--turbo), which reduces generation time to ~10-20 seconds (requires a Midjourney Pro or Mega plan). The --aspect-ratio is automatically appended to the prompt as --ar <ratio>. The model always generates 4 images in a grid. After generation, you can:

• Ask the user if they want to upscale (U1-U4) or create variations (V1-V4) of any image.
• Use --action upscale --index <1-4> --job-id <id> to upscale a specific image.
• Use --action variation --index <1-4> --job-id <id> to create variations.
• Use --action reroll --job-id <id> to re-generate with the same prompt.

Upscale types (via --upscale-type):

• 0 = Subtle (default): Conservative enhancement, preserves original details. Best for photography.
• 1 = Creative: More artistic interpretation. Best for illustrations.

Variation types (via --variation-type):

• 0 = Subtle (default): Minor changes while preserving composition.
• 1 = Strong: More dramatic variations with significant changes.

# Upscale image 2 from a previous Midjourney generation (subtle)
node {baseDir}/generate.js \
  --model midjourney \
  --action upscale \
  --index 2 \
  --job-id <previous_job_id> \
  --upscale-type 0

# Create a strong variation of image 3
node {baseDir}/generate.js \
  --model midjourney \
  --action variation \
  --index 3 \
  --job-id <previous_job_id> \
  --variation-type 1

# Reroll (regenerate with same prompt)
node {baseDir}/generate.js \
  --model midjourney \
  --action reroll \
  --job-id <previous_job_id>

Prompt Enhancement Tips

• For Midjourney: Add style keywords like cinematic lighting, photorealistic, --v 7, --style raw, --ar 16:9. Legnext.ai supports all MJ parameters.
• For Flux: Add quality boosters like masterpiece, highly detailed, sharp focus, professional photography
• For Ideogram: Be explicit about text content, font style, and layout
• For Recraft: Specify vector illustration, flat design, icon style, SVG-style

Environment Variables

This skill requires the following environment variables to be set in your OpenClaw config:

Configure them in ~/.openclaw/openclaw.json:

{
  "skills": {
    "entries": {
      "image-gen": {
        "enabled": true,
        "env": {
          "FAL_KEY": "your_fal_key_here",
          "LEGNEXT_KEY": "your_legnext_key_here"
        }
      }
    }
  }
}

Example Conversations

User: "帮我画一只在雪山上的雪豹，电影感光效" Action: Select midjourney, enhance prompt to "a majestic snow leopard on a snowy mountain peak, cinematic lighting, dramatic atmosphere, ultra detailed --ar 16:9 --v 7", run script.

User: "用 Flux 生成一张产品海报，白色背景，一瓶香水" Action: Select flux-pro, enhance prompt, run script with --aspect-ratio 3:4.

User: "快速生成一个草稿看看效果" Action: Select flux-schnell for fastest generation (<2 seconds).

User: "帮我做一个 App 图标，扁平风格，蓝色系" Action: Select recraft, use prompt with flat design icon, blue color scheme, minimal, vector style.

User: "把第2张图片放大" Action: Run with --model midjourney --action upscale --index 2 --job-id <id>.