---
name: create-thumbnail
description: >
  Generate YouTube-style 16:9 thumbnails with Unsora — face references,
  template styles, expressions, and multiple variations. Use when the user wants
  a thumbnail, CTR cover, YouTube preview image, or click-worthy still.
---

# Create Thumbnail

Generate 16:9 YouTube-style thumbnails via `create_thumbnail`.

---

## Workflow

1. **Gather inputs:**
   - **Topic / hook** — what the video is about (becomes `prompt` or `context`)
   - **Face reference** — public URL of creator face (`referenceImageUrls`) for likeness lock
   - **Template reference** — optional single template image URL (`templateImageUrls`, max 1) to mimic a layout style
   - **Expression** — e.g. shocked, confident, pointing (optional `expression` field)
   - **Variations** — 1–10 parallel options (`variations`, default 3–4 for A/B testing)

2. `get_credits`
3. `create_thumbnail` with assembled body
4. **Preview hosts** — thumbnail grid preview polls automatically; do not call `wait_for_image`
5. **Other hosts** — `wait_for_image` per returned generation id

---

## Prompt structure

Thumbnails need **high contrast and readable hierarchy**:

- **Subject** — face position (left/right/center), expression, gesture
- **Text overlay** — 2–5 bold words max (if user wants text in the image)
- **Background** — simple, not busy; supports the hook
- **Colors** — saturated, platform-native (YouTube dark mode friendly)

**Example prompt context:** *"Tech review thumbnail — creator on left with surprised expression, product floating right, bold yellow text 'IT'S FINALLY HERE', dark gradient background, high CTR energy."*

Pass rich detail via `prompt` and/or `context` array for multi-line briefs.

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## Reference images

- Face refs: use clear, well-lit photos; HTTPS URLs only
- Template ref: one layout the user wants to emulate (competitor thumbnail, past winner)

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## After delivery

Offer: more variations, different expression, generate matching video hook (`unsora:create-video`), or schedule as slideshow post.

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## Tips

- Ask for the video title/hook if not provided — thumbnails sell the click, not the full video
- Default to 3–4 variations so the user can pick a winner
- 16:9 is fixed for this tool — do not ask for other ratios