Cover Image Generator

Generate elegant cover images for articles with 5-dimensional customization.

User Input Tools

When this skill prompts the user, follow this tool-selection rule (priority order):

1. Prefer built-in user-input tools exposed by the current agent runtime — e.g., AskUserQuestion, request_user_input, clarify, ask_user, or any equivalent.
2. Fallback: if no such tool exists, emit a numbered plain-text message and ask the user to reply with the chosen number/answer for each question.
3. Batching: if the tool supports multiple questions per call, combine all applicable questions into a single call; if only single-question, ask them one at a time in priority order.

Concrete AskUserQuestion references below are examples — substitute the local equivalent in other runtimes.

Image Generation Tools

When this skill needs to render an image, resolve the backend in this order:

1. Current-request override — if the user names a specific backend in the current message, use it.
2. Saved preference — if EXTEND.md sets preferred_image_backend to a backend available right now, use it.
3. Auto-select (when the preference is auto, unset, or the pinned backend isn't available):
   • If the current runtime exposes a native image tool (e.g., Codex imagegen, Hermes image_generate), use it. Runtime-native tools are preferred by default — agents that know their own tool inventory should surface the native one here.
   • Otherwise, if exactly one non-native backend is installed (e.g., baoyu-imagine), use it.
   • Otherwise (multiple non-native backends with no runtime-native tool), ask the user once — batch with any other initial questions.
4. If none are available, tell the user and ask how to proceed.

Setting preferred_image_backend: ask forces the step-3 prompt every run regardless of available backends. Users change the pinned backend via the ## Changing Preferences section below.

Prompt file requirement (hard): write each image's full, final prompt to a standalone file under prompts/ (naming: NN-{type}-[slug].md) BEFORE invoking any backend. The backend receives the prompt file (or its content); the file is the reproducibility record and lets you switch backends without regenerating prompts.

Concrete tool names (imagegen, image_generate, baoyu-imagine) above are examples — substitute the local equivalents under the same rule.

Confirmation Policy

Default behavior: confirm before generation.

• Treat explicit skill invocation, a file path, matched keywords/presets, EXTEND.md defaults, and any documented auto-selection as recommendation inputs only. None of them authorizes skipping confirmation.
• Do not start Step 3 or Step 4 until the user confirms the dimensions / aspect / language / backend choices.
• Skip confirmation only when the current request explicitly says to do so, for example: --quick, "直接生成", "不用确认", "跳过确认", "按默认出图", or equivalent wording. quick_mode: true in EXTEND.md counts as a standing explicit opt-out — set it only when you want every run to skip Step 2.
• If confirmation is skipped explicitly, state the assumed dimensions / aspect / language / backend in the next user-facing update before generating.

Options

Five Dimensions

Auto-selection rules: references/auto-selection.md

Galleries

Types: hero, conceptual, typography, metaphor, scene, minimal → Details: references/types.md

Palettes: warm, elegant, cool, dark, earth, vivid, pastel, mono, retro, duotone, macaron → Details: references/palettes/

Renderings: flat-vector, hand-drawn, painterly, digital, pixel, chalk, screen-print → Details: references/renderings/

Text Levels: none (pure visual) | title-only (default) | title-subtitle | text-rich (with tags) → Details: references/dimensions/text.md

Mood Levels: subtle (low contrast) | balanced (default) | bold (high contrast) → Details: references/dimensions/mood.md

Fonts: clean (sans-serif) | handwritten | serif | display (bold decorative) → Details: references/dimensions/font.md

File Structure

Output directory per default_output_dir preference:

• same-dir: {article-dir}/
• imgs-subdir: {article-dir}/imgs/
• independent (default): cover-image/{topic-slug}/

<output-dir>/
├── source-{slug}.{ext}    # Source files
├── refs/                  # Reference images (if provided)
│   ├── ref-01-{slug}.{ext}
│   └── ref-01-{slug}.md   # Description file
├── prompts/cover.md       # Generation prompt
└── cover.png              # Output image

Slug: 2-4 words, kebab-case. Conflict: append -YYYYMMDD-HHMMSS

Workflow

Progress Checklist

Cover Image Progress:
- [ ] Step 0: Check preferences (EXTEND.md) ⛔ BLOCKING
- [ ] Step 1: Analyze content + save refs + determine output dir
- [ ] Step 2: Confirm options (6 dimensions) ⚠️ unless --quick
- [ ] Step 3: Create prompt
- [ ] Step 4: Generate image
- [ ] Step 5: Completion report

Flow

Input → [Step 0: Preferences] ─┬─ Found → Continue
                               └─ Not found → First-Time Setup ⛔ BLOCKING → Save EXTEND.md → Continue
        ↓
Analyze + Save Refs → [Output Dir] → [Confirm: 6 Dimensions] → Prompt → Generate → Complete
                                              ↓
                                     (skip if --quick or all specified)

Step 0: Load Preferences ⛔ BLOCKING

Check EXTEND.md in priority order — the first one found wins:

CRITICAL: If not found, complete setup BEFORE any other steps or questions.

Step 1: Analyze Content

1. Save reference images (if provided) → references/workflow/reference-images.md
2. Save source content (if pasted, save to source.md)
3. Analyze content: topic, tone, keywords, visual metaphors
4. Deep analyze references ⚠️: Extract specific, concrete elements (see reference-images.md)
5. Detect language: Compare source, user input, EXTEND.md preference
6. Determine output directory: Per File Structure rules

⚠️ People in Reference Images:

If reference images contain people who should appear in the cover:

• Model supports --ref (default): Copy image to refs/, pass via --ref at generation. No description file needed — the model sees the face directly.
• Model does NOT support --ref (Jimeng, Seedream 3.0): Create refs/ref-NN-{slug}.md with per-character description (hair, glasses, skin tone, clothing). Embed as MUST/REQUIRED instructions in prompt text.

See reference-images.md for full decision table.

Step 2: Confirm Options ⚠️

Hard gate: this step is mandatory per the Confirmation Policy — Steps 3–4 cannot start until the user confirms here (or explicitly opts out with --quick / quick_mode: true / equivalent wording in the current request).

MUST use AskUserQuestion tool to present options as interactive selection — NOT plain text tables. Present up to 4 questions in a single AskUserQuestion call (Type, Palette, Rendering, Font + Settings). Each question shows the recommended option first with reason, followed by alternatives.

Full confirmation flow and question format: references/workflow/confirm-options.md

Step 3: Create Prompt

Save to prompts/cover.md. Template: references/workflow/prompt-template.md

CRITICAL - References in Frontmatter:

• Files saved to refs/ → Add to frontmatter references list
• Style extracted verbally (no file) → Omit references, describe in body
• Before writing → Verify: test -f refs/ref-NN-{slug}.{ext}

Reference elements in body MUST be detailed, prefixed with "MUST"/"REQUIRED", with integration approach.

Step 4: Generate Image

1. Backup existing cover.png if regenerating
2. Select backend via the ## Image Generation Tools rule at the top: use whatever is available; if multiple, ask the user once. Do this once per session before any generation.
3. Write the full final prompt to prompts/01-cover-[slug].md (hard requirement) BEFORE invoking the backend.
4. Process references from prompt frontmatter:
   • direct usage → pass via --ref (use ref-capable backend)
   • style/palette → extract traits, append to prompt
5. Generate: Call the chosen backend with the prompt file, output path, aspect ratio
6. On failure: auto-retry once

Step 5: Completion Report

Cover Generated!

Topic: [topic]
Type: [type] | Palette: [palette] | Rendering: [rendering]
Text: [text] | Mood: [mood] | Font: [font] | Aspect: [ratio]
Title: [title or "visual only"]
Language: [lang] | Watermark: [enabled/disabled]
References: [N images or "extracted style" or "none"]
Location: [directory path]

Files:
✓ source-{slug}.{ext}
✓ prompts/cover.md
✓ cover.png

Image Modification

Composition Principles

• Whitespace: 40-60% breathing room
• Visual anchor: Main element centered or offset left
• Characters: Simplified silhouettes; NO realistic humans
• Title: Use exact title from user/source; never invent

Changing Preferences

EXTEND.md lives at the path noted in Step 0. Three ways to change it:

• Edit directly — open EXTEND.md and change fields. Full schema: references/config/preferences-schema.md.
• Reconfigure interactively — delete EXTEND.md (or ask "reconfigure baoyu-cover-image preferences" / "重新配置"). The next run re-triggers first-time setup.
• Common one-line edits:
  • preferred_image_backend: auto — default; runtime-native tool wins, falls back to the only installed backend, asks only if multiple non-native are present.
  • preferred_image_backend: codex-imagegen — pin to Codex's built-in.
  • preferred_image_backend: baoyu-imagine — pin to the baoyu-imagine skill.
  • preferred_image_backend: ask — confirm backend every run.
  • watermark.enabled: true, preferred_type, preferred_palette, preferred_rendering, default_aspect, quick_mode: true, language — shift the auto-selection defaults and confirmation flow.

References

Dimensions: text.md | mood.md | font.md Palettes: references/palettes/ Renderings: references/renderings/ Types: references/types.md Auto-Selection: references/auto-selection.md Style Presets: references/style-presets.md Compatibility: references/compatibility.md Visual Elements: references/visual-elements.md Workflow: confirm-options.md | prompt-template.md | reference-images.md Config: preferences-schema.md | first-time-setup.md | watermark-guide.md