generate-image-high-seedream

name: generate-image-high-seedream description: generate high-quality images using bytedance-seed/seedream-4.5 (high-tier). use ONLY when explicitly requested by board or manager for production/final deliverables.

Generate Image — High Tier (bytedance-seed/seedream-4.5)

Generate high-quality images via OpenRouter using the SeedDream 4.5 model.

IMPORTANT: Use this skill only when the board or your manager explicitly requests high-tier quality. Default to generate-image-low-flux for all drafts and iterations.

Quick Start — Text to Image

curl -s -X POST "https://openrouter.ai/api/v1/chat/completions" \
  -H "Authorization: Bearer $OPENROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "bytedance-seed/seedream-4.5",
    "messages": [{"role": "user", "content": "A minimalist logo on white background"}]
  }' | python3 -c "
import json, sys, base64; from pathlib import Path
data = json.load(sys.stdin)
url = data['choices'][0]['message']['images'][0]['image_url']['url']
Path('output').mkdir(exist_ok=True)
Path('output/generated.png').write_bytes(base64.b64decode(url.split(',',1)[1]))
print('Saved to output/generated.png')
"

With Aspect Ratio and Size

Add image_config to the payload for aspect ratio and resolution control:

curl -s -X POST "https://openrouter.ai/api/v1/chat/completions" \
  -H "Authorization: Bearer $OPENROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "bytedance-seed/seedream-4.5",
    "messages": [{"role": "user", "content": "Brand hero image, dark navy background"}],
    "image_config": {"aspect_ratio": "16:9", "image_size": "2K"}
  }' | python3 -c "
import json, sys, base64; from pathlib import Path
data = json.load(sys.stdin)
url = data['choices'][0]['message']['images'][0]['image_url']['url']
Path('output').mkdir(exist_ok=True)
Path('output/hero.png').write_bytes(base64.b64decode(url.split(',',1)[1]))
print('Saved to output/hero.png')
"

With Input Image (Editing)

Encode the input image as a base64 data URL and pass it as an image_url content part:

IMG_B64=$(base64 -i reference.png)
curl -s -X POST "https://openrouter.ai/api/v1/chat/completions" \
  -H "Authorization: Bearer $OPENROUTER_API_KEY" \
  -H "Content-Type: application/json" \
  -d "$(python3 -c "
import json
payload = {
    'model': 'bytedance-seed/seedream-4.5',
    'messages': [{'role': 'user', 'content': [
        {'type': 'text', 'text': 'Refine the colors and lighting'},
        {'type': 'image_url', 'image_url': {'url': 'data:image/png;base64,$(cat <<< $IMG_B64)'}}
    ]}],
    'image_config': {'image_size': '2K'}
}
print(json.dumps(payload))
")" | python3 -c "
import json, sys, base64; from pathlib import Path
data = json.load(sys.stdin)
url = data['choices'][0]['message']['images'][0]['image_url']['url']
Path('output').mkdir(exist_ok=True)
Path('output/refined.png').write_bytes(base64.b64decode(url.split(',',1)[1]))
print('Saved to output/refined.png')
"

With Multiple Input Images

Same approach — add multiple image_url content parts:

python3 -c "
import json, base64, sys, os, requests
from pathlib import Path

prompt = 'Merge these into a single banner'
input_files = ['logo.png', 'hero.png', 'badge.png']
output_file = 'output/banner.png'

content = [{'type': 'text', 'text': prompt}]
for f in input_files:
    b64 = base64.b64encode(Path(f).read_bytes()).decode()
    content.append({'type': 'image_url', 'image_url': {'url': f'data:image/png;base64,{b64}'}})

resp = requests.post('https://openrouter.ai/api/v1/chat/completions',
    headers={'Authorization': f'Bearer {os.environ[\"OPENROUTER_API_KEY\"]}', 'Content-Type': 'application/json'},
    json={'model': 'bytedance-seed/seedream-4.5', 'messages': [{'role': 'user', 'content': content}],
          'image_config': {'aspect_ratio': '16:9', 'image_size': '2K'}},
    timeout=180)

data = resp.json()
if 'error' in data:
    print(f'ERROR: {data[\"error\"]}', file=sys.stderr); sys.exit(1)
url = data['choices'][0]['message']['images'][0]['image_url']['url']
Path(output_file).parent.mkdir(parents=True, exist_ok=True)
Path(output_file).write_bytes(base64.b64decode(url.split(',',1)[1]))
print(f'Saved to {output_file}')
"

Requires OPENROUTER_API_KEY in environment.

Parameters

IMPORTANT: Do NOT include modalities in the payload. SeedDream returns images by default — adding "modalities": ["image", "text"] causes a 404 error.

Response Format

{
  "choices": [{
    "message": {
      "images": [{
        "type": "image_url",
        "image_url": {"url": "data:image/jpeg;base64,..."}
      }]
    }
  }]
}

Extract: choices[0].message.images[0].image_url.url — base64 data URL.

Error Handling

• HTTP 402 / Insufficient credits: Do NOT retry or switch models. Ask user to add credits at https://openrouter.ai/settings/credits.
• HTTP 404 "No endpoints found": You are sending modalities in the payload. Remove it.
• HTTP 401: API key missing or invalid.
• HTTP 429: Wait a few seconds, retry once.

Aspect Ratios by Use Case

Design Guidance

For prompt engineering and brand consistency, read references/design-guidelines.md.