Image Generation (AI SDK)

Official API-based image generation. Supports OpenAI, Google, DashScope (阿里通义万象), and Canghe providers.

Script Directory

Agent Execution:

1. SKILL_DIR = this SKILL.md file's directory
2. Script path = ${SKILL_DIR}/scripts/main.ts

Preferences (EXTEND.md)

Use Bash to check EXTEND.md existence (priority order):

# Check project-level first
test -f .canghe-skills/canghe-image-gen/EXTEND.md && echo "project"

# Then user-level (cross-platform: $HOME works on macOS/Linux/WSL)
test -f "$HOME/.canghe-skills/canghe-image-gen/EXTEND.md" && echo "user"

┌──────────────────────────────────────────────────┬───────────────────┐ │ Path │ Location │ ├──────────────────────────────────────────────────┼───────────────────┤ │ .canghe-skills/canghe-image-gen/EXTEND.md │ Project directory │ ├──────────────────────────────────────────────────┼───────────────────┤ │ $HOME/.canghe-skills/canghe-image-gen/EXTEND.md │ User home │ └──────────────────────────────────────────────────┴───────────────────┘

┌───────────┬───────────────────────────────────────────────────────────────────────────┐ │ Result │ Action │ ├───────────┼───────────────────────────────────────────────────────────────────────────┤ │ Found │ Read, parse, apply settings │ ├───────────┼───────────────────────────────────────────────────────────────────────────┤ │ Not found │ Use defaults │ └───────────┴───────────────────────────────────────────────────────────────────────────┘

EXTEND.md Supports: Default provider | Default quality | Default aspect ratio | Default image size | Default models

Schema: references/config/preferences-schema.md

Usage

# Basic
npx -y bun ${SKILL_DIR}/scripts/main.ts --prompt "A cat" --image cat.png

# With aspect ratio
npx -y bun ${SKILL_DIR}/scripts/main.ts --prompt "A landscape" --image out.png --ar 16:9

# High quality
npx -y bun ${SKILL_DIR}/scripts/main.ts --prompt "A cat" --image out.png --quality 2k

# From prompt files
npx -y bun ${SKILL_DIR}/scripts/main.ts --promptfiles system.md content.md --image out.png

# With reference images (Google multimodal or OpenAI edits)
npx -y bun ${SKILL_DIR}/scripts/main.ts --prompt "Make blue" --image out.png --ref source.png

# With reference images (explicit provider/model)
npx -y bun ${SKILL_DIR}/scripts/main.ts --prompt "Make blue" --image out.png --provider google --model gemini-3-pro-image-preview --ref source.png

# Specific provider
npx -y bun ${SKILL_DIR}/scripts/main.ts --prompt "A cat" --image out.png --provider openai

# DashScope (阿里通义万象)
npx -y bun ${SKILL_DIR}/scripts/main.ts --prompt "一只可爱的猫" --image out.png --provider dashscope

# Canghe third-party gateway
npx -y bun ${SKILL_DIR}/scripts/main.ts --prompt "一只可爱的猫" --image out.png --provider canghe

Options

Option	Description
--prompt <text>, -p	Prompt text
--promptfiles <files...>	Read prompt from files (concatenated)
--image <path>	Output image path (required)
--provider google|openai|dashscope|canghe	Force provider (default: google)
--model <id>, -m	Model ID (--ref with OpenAI requires GPT Image model, e.g. gpt-image-1.5)
--ar <ratio>	Aspect ratio (e.g., 16:9, 1:1, 4:3)
--size <WxH>	Size (e.g., 1024x1024)
--quality normal|2k	Quality preset (default: 2k)
--imageSize 1K|2K|4K	Image size for Google (default: from quality)
--ref <files...>	Reference images. Supported by Google multimodal, OpenAI edits (GPT Image models), and Canghe (image_url). If provider omitted: Google first, then OpenAI, then Canghe
--n <count>	Number of images
--json	JSON output

Environment Variables

Variable	Description
OPENAI_API_KEY	OpenAI API key
GOOGLE_API_KEY	Google API key
DASHSCOPE_API_KEY	DashScope API key (阿里云)
CANGHE_API_KEY	Canghe API key
OPENAI_IMAGE_MODEL	OpenAI model override
GOOGLE_IMAGE_MODEL	Google model override
DASHSCOPE_IMAGE_MODEL	DashScope model override (default: z-image-turbo)
CANGHE_IMAGE_MODEL	Canghe model override (default: gemini-3-pro-image-preview)
OPENAI_BASE_URL	Custom OpenAI endpoint
GOOGLE_BASE_URL	Custom Google endpoint
DASHSCOPE_BASE_URL	Custom DashScope endpoint
CANGHE_BASE_URL	Custom Canghe endpoint (default: https://api.canghe.ai/v1)

Load Priority: CLI args > EXTEND.md > env vars > <cwd>/.canghe-skills/.env > ~/.canghe-skills/.env

Provider Selection

1. --ref provided + no --provider → auto-select Google first, then OpenAI, then Canghe
2. --provider specified → use it (if --ref, must be google or openai or canghe)
3. Only one API key available → use that provider
4. Multiple available → default to Google

Quality Presets

Preset	Google imageSize	OpenAI Size	Use Case
normal	1K	1024px	Quick previews
2k (default)	2K	2048px	Covers, illustrations, infographics

Google imageSize: Can be overridden with --imageSize 1K|2K|4K

Aspect Ratios

Supported: 1:1, 16:9, 9:16, 4:3, 3:4, 2.35:1

• Google multimodal: uses imageConfig.aspectRatio
• Google Imagen: uses aspectRatio parameter
• OpenAI: maps to closest supported size

Generation Mode

Default: Sequential generation (one image at a time). This ensures stable output and easier debugging.

Parallel Generation: Only use when user explicitly requests parallel/concurrent generation.

Mode	When to Use
Sequential (default)	Normal usage, single images, small batches
Parallel	User explicitly requests, large batches (10+)

Parallel Settings (when requested):

Setting	Value
Recommended concurrency	4 subagents
Max concurrency	8 subagents
Use case	Large batch generation when user requests parallel

Agent Implementation (parallel mode only):

# Launch multiple generations in parallel using Task tool
# Each Task runs as background subagent with run_in_background=true
# Collect results via TaskOutput when all complete

Error Handling

• Missing API key → error with setup instructions
• Generation failure → auto-retry once
• Invalid aspect ratio → warning, proceed with default
• Reference images with unsupported provider/model → error with fix hint (switch to Google multimodal or OpenAI GPT Image edits)

Extension Support

Custom configurations via EXTEND.md. See Preferences section for paths and supported options.