Generate YouTube Thumbnail

A reusable workflow for creating YouTube thumbnails via Arcads' Nano Banana 2 image endpoint with proper character likeness and proven CTR formulas.

When to use this skill

Trigger on phrases like:

• "make me a YouTube thumbnail"
• "create a thumbnail for this video"
• "I need thumbnail variations / A/B tests"
• "remake this thumbnail with my face"
• "generate 10 thumbnail concepts"
• "thumbnail with [me / my product / my brand]"

Read order

1. This file, workflow, decision tree, batch generation
2. shared/skills/generate-youtube-thumbnail/prompting/guide.md, likeness alignment, expressions cheat sheet, prompt structure (shared across all generative-AI APIs in this portfolio)
3. shared/skills/generate-youtube-thumbnail/prompting/formulas.md, 5 proven thumbnail formulas with templates (shared)
4. scripts/generate-batch.sh, Arcads-specific batch script (presigned upload + S3 PUT pipeline)

Prerequisites

• .env with ARCADS_BASIC_AUTH and ARCADS_API_KEY
• A productId (defaults to MASTER_CONTEXT.md's "My workspace" product)
• Reference images on disk (NOT pasted in chat, chat-pasted images are NOT accessible to the API):
  • face/, 5+ photos of the subject (headshot + 3/4 angles + close-ups + expressions)
  • logos/, brand logos as files (orange Claude Code starburst, black Arcads A, etc.)
  • products/, clean product shots
  • examples/, real ad screenshots, comparison material
  • style/, example thumbnails the user wants to match aesthetically

If references are missing or the user pastes images in chat instead of saving them, stop and ask the user to drop the actual files into a project folder (e.g. references/youtube thumbnail/). Chat paste ≠ file on disk.

Workflow

1. Gather requirements (in order)