YouTube Thumbnail

SkillMedia

Lets your agent design an eye-catching YouTube thumbnail with bold imagery and text.

Available today. Use it from your connected AI after setup.

Connect ahel once, and every AI you use reads what you have installed.

Then ask your AI: use the YouTube Thumbnail skill

About this capability

Design a high-CTR YouTube thumbnail — striking imagery, bold text placement, and emotional face/subject if needed.

What this skill tells your AI

The instructions your AI receives, as published by samuraigpt/generative-media-skills in .opencode/skills/muapi-youtube-thumbnail/SKILL.md and read by ahel’s review.

Design a high-CTR YouTube thumbnail — striking imagery, bold text placement, and emotional face/subject if needed.

Inputs

NameTypeRequiredDefaultDescription
titletextyesThe video title or topic (e.g. "I tried 7 AI tools in 24 hours — here's what happened").
channel_styletextnobold, high contrast, bright colors, clean design, YouTube tech aestheticChannel brand style (e.g. "dark moody gaming", "bright educational", "minimal corporate").
subject_descriptiontextnoOptional description of the person or subject to feature (e.g. "a surprised young man in a hoodie").

Steps

Thumbnails are the #1 factor in YouTube CTR. Generate a single, maximum-impact 16:9 image.

Phase A — Plan the composition

Before generating, briefly reason about the best thumbnail formula for this topic:

  • Emotion-first: shocked/curious face if relevant + bold text = high CTR
  • Text overlay: 3–5 words max, high-contrast (white/yellow on dark, or vice-versa)
  • Contrast & saturation: thumbnails compete in a grid — they must pop

Phase B — Generate the thumbnail

  1. Build the image generation prompt:
    • Subject: {{subject_description}} if provided, otherwise design an object/scene that dramatizes the topic.
    • Mood: derives from {{channel_style}}.
    • Composition: rule-of-thirds, subject on left or right with empty space for text.
    • Style tags: {{channel_style}}, youtube thumbnail composition, ultra detailed, vibrant, high contrast, 16:9.
  2. Call muapi image generate (model=gpt-image-2-text-to-image, aspect_ratio=16:9).

Phase C — Text overlay guidance

After generation, return:

  • Suggested overlay text: 3–5 bold words that complement the title {{title}}.
  • Text placement: where on the canvas to position text (e.g. "bold yellow text, top-right third").
  • Font recommendation: style suggestion (e.g. "Impact-style all-caps with black outline").

Notes

  • Never put too much text in the prompt — text rendering in image models is unreliable. Guide the user on adding text in post-production (Canva, Photoshop).
  • If the user already has a channel image or face photo in the session, use muapi image edit to incorporate it.
  • Suggest A/B variants only if the user asks.

Trigger Keywords

youtube thumbnail, yt thumbnail, thumbnail, video thumbnail, youtube cover


Notes for the Executing Agent

  • This recipe is LLM-orchestrated: read each phase, gather any missing inputs from the user, then call muapi CLI commands. Use muapi auth configure first if MUAPI_API_KEY is unset.
  • For model IDs without a CLI alias yet, fall back to the raw endpoint via curl -X POST https://api.muapi.ai/api/v1/<endpoint> -H "x-api-key: $MUAPI_API_KEY" -H 'content-type: application/json' -d '{...}' and poll with muapi predict wait <request_id>.
  • Substitute {{input_name}} placeholders with the user's actual inputs before issuing each call.

Signals

GitHub stars
4k
Forks
489
Last commit
Sep 2026

ahel review

  • K2info
    exfiltration

Automated review, not a security audit. Ruleset v1+k2.

Advanced
Catalog kind
skill
Gateway key
muapi-youtube-thumbnail
Source
github.com/samuraigpt/generative-media-skills