image-generation - SKILL.md Agent Skill

name: image-generation description: Generate images using Google Gemini (gemini-3-pro-image-preview). Requires GEMINI_API_KEY. envVars:

name: GEMINI_API_KEY description: Google AI Studio / Gemini API key required: true

Image Generation

Generate images using Google Gemini (gemini-3-pro-image-preview) for both text-to-image and image-to-image workflows.

Use the packaged CLI:

middleman image generate \
  --prompt "a cute robot bee in a garden" \
  --output "/path/to/output.png"

Image-to-image generation is supported with repeated --input-image flags:

middleman image generate \
  --prompt "turn this sketch into a painted poster with a limited teal and coral palette" \
  --input-image "/path/to/sketch.png" \
  --input-image "/path/to/reference.jpg" \
  --output "/path/to/output.png"

Options

--prompt (required): text description of the image to generate
--output (required): output file path (extension auto-detected when omitted)
--input-image (optional, repeatable): local source image(s) to send alongside the prompt
--aspect-ratio (optional): aspect ratio like 16:9, 1:1, 4:3
--size (optional): image size, default 1K

Output

The script prints JSON:

Success: { "ok": true, "file": "/path/to/output.png", "mimeType": "image/png" }
Failure: { "ok": false, "error": "..." }