Jimeng API Image Gen

Jimeng API Image Generation

Generate high-quality AI images using Volcengine's Jimeng 4.0 API with text prompts or image inputs.

Configure Environment Variables

Get Access Key/Secret Key

# ~/.zshrc or ~/.zshenv
export VOLC_ACCESSKEY="your_access_key_id"
export VOLC_SECRETKEY="your_secret_access_key"

Output Behavior (Important)

After image generation succeeds, you MUST display the image directly to the user!

When generation completes, output in the following format:

![Generated Image](IMAGE_URL)

**Generation Info:**
- Prompt: [User's original prompt]
- Size: [Image dimensions]
- Save Path: [Local file path, if applicable]

Example Output

![Shiba Inu under cherry blossoms](https://example.com/image.png)

**Generation Info:**
- Prompt: Shiba Inu under cherry blossom tree, warm sunlight, healing art style
- Size: 2304 × 1728
- Save Path: /generated_images/[Generated Image] **important**

Notes

1. Prefer markdown image syntax ![description](URL) to display images directly
2. Also provide the online link for easy copying and sharing
3. If saved locally, display the local file path
4. For multiple images, display each one with numbered labels

Quick Start

Step 1: Run Generation

# Text-to-image
scripts/generate_image.py "A white Siamese cat sitting on a windowsill, sunlight streaming in"

# With specific size
scripts/generate_image.py "Mountain sunset landscape" --size 2K

# Image-to-image editing
scripts/generate_image.py "Change to watercolor style" --images https://example.com/input.jpg

# Save to file
scripts/generate_image.py "Serene lake at sunset" --output /generated_images/lake.png

API Configuration

Image Size Options

Preset Resolutions

Exact Dimensions

Use --width and --height together:

scripts/generate_image.py "prompt" --width 2560 --height 1440

Recommended aspect ratios:

• 1:1 (2048x2048) - Social media posts
• 4:3 (2304x1728) - Presentations
• 16:9 (2560x1440) - Widescreen displays
• 9:16 (1440x2560) - Mobile vertical
• 3:2 (2496x1664) - Photography

Constraints:

• Width × Height must be in [1024×1024, 4096×4096]
• Aspect ratio (width/height) in [1/16, 16]
• Recommended: Use 2K+ for better quality

Command-Line Options

scripts/generate_image.py PROMPT [OPTIONS]

Arguments:
  PROMPT              Text prompt for image generation (required, max 800 chars)

Options:
  --size SIZE         Image size: 1K, 2K, 4K or WxH (default: 2K)
  --width WIDTH       Exact width (requires --height)
  --height HEIGHT     Exact height (requires --width)
  --images URL [...]  Input image URLs for image-to-image (max 10)
  --watermark         Add "AI Generated" watermark
  --scale FLOAT       Text influence 0-1 (default: 0.5)
  --force-single      Force single image output
  --output PATH       Download image to file
  --json              Output raw JSON response

Environment Variables:
  VOLC_ACCESSKEY           Access Key ID (required)
  VOLC_SECRETKEY           Secret Access Key (required)
  JIMENG_API_URL           API endpoint (default: https://visual.volcengineapi.com)
  JIMENG_API_TIMEOUT       Request timeout seconds (default: 120)
  JIMENG_POLL_INTERVAL     Polling interval seconds (default: 2)
  JIMENG_MAX_POLL_ATTEMPTS Max polling attempts (default: 60)

Authentication

This skill uses Volcengine IAM v4 signature authentication (HMAC-SHA256). The signing process:

1. Build canonical request with headers: content-type;host;x-content-sha256;x-date
2. Calculate SHA256 hash of canonical request
3. Derive signing key: secret_key → date → region → service → "request"
4. Sign the string-to-sign with derived key
5. Add Authorization header to request

Reference: HTTP请求示例

Error Codes

Input/Output Limits

Input Images:

• Format: JPEG, PNG only
• Max files: 10 images
• Max size: 15MB per image
• Max resolution: 4096×4096
• Aspect ratio (W/H): [1/3, 3]

Output:

• Max images: 15 - (input image count)
• Format: PNG
• URL validity: 24 hours

Reference Documentation

• Jimeng AI 4.0 API Documentation
• HTTP Request Example
• Volcengine Console
• API Key Management