YouTube Thumbnail

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

Inputs

| Name | Type | Required | Default | Description | |:---|:---|:---|:---|:---| | title | text | yes | — | The video title or topic (e.g. "I tried 7 AI tools in 24 hours — here's what happened"). | | channel_style | text | no | bold, high contrast, bright colors, clean design, YouTube tech aesthetic | Channel brand style (e.g. "dark moody gaming", "bright educational", "minimal corporate"). | | subject_description | text | no | — | Optional 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.

1. 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.