How to Use the Seedream V4 API: text to image integration guide (2026)
Learn how to call the Seedream V4 API on NamiFusion: parameters, pricing (from ≈$0.030) and runnable copy-paste code — try it in the playground first.
Seedream V4 is a text to image model by Doubao: Seedream 4.0 by is a state-of-the-art image generation model delivering high-fidelity outputs and outperforming Nano Banana. Ready-to-use REST inference API, best performance, no coldstarts, affordable pricing. On NamiFusion you can try it in the playground (exact quote shown before you submit), then call it through one unified REST API — a typical run costs about $0.030.
TL;DR
· Task type: text to image, provided by Doubao
· Pricing: about $0.030 per typical run ($1 = 100 credits), pay-as-you-go
· Getting started: playground (exact quote before submit) → create an API key → one POST request
· Tunable parameters: 2 (see the table below)
· No platform watermark; commercial use allowed (per the Terms of Service)
What can you build with Seedream V4?
Social media visuals and covers: batch-generate on-theme images and schedule them straight away.
E-commerce and ad creatives: product scenes, banner backgrounds, and multi-variant visuals for A/B tests.
Concept art and ideation: characters, environments and style boards, iterated cheaply and fast.
Pipeline chaining: outputs feed directly into image-to-video or face swap as source material.
How do you call this API?
1. Sign up on NamiFusion and create a key on the API Keys page (free credits on signup).
2. Submit a task with the cURL example below, passing your key as a Bearer token.
3. Poll the task status with the returned task_uuid and read the output URLs when completed.
# 1) Submit — returns { "task_uuid": "..." }
curl -X POST "https://www.namifusion.com/api/v1/marketplace/run/doubao/seedream-4.0/text-to-image" \
-H "Authorization: Bearer YOUR_API_KEY" \
-H "Content-Type: application/json" \
-d '{
"input": {
"prompt": "A photorealistic image of a serene mountain landscape during sunrise, featuring snow-capped peaks, a calm lake reflecting the sunlight, and lush greenery surrounding the scene.",
"size": "1920x1080"
}
}'
# 2) Poll until status is "completed", then read the output URLs
curl "https://www.namifusion.com/api/v1/marketplace/run/tasks/TASK_UUID" \
-H "Authorization: Bearer YOUR_API_KEY"What parameters does it take?
prompt (Prompt): required
size (Size): optional, default "2048x2048"
How do you write prompts for Seedream V4?
1. Subject first: lead with the actor and action, then add environment, lighting and style ("an astronaut sprinting through a neon street in the rain, cinematic, shallow depth of field").
2. Concrete nouns beat stacked adjectives: "85mm portrait lens, golden-hour backlight" works far better than "very beautiful, ultra high quality".
3. Change one variable per iteration: pin the seed to reproduce a result, tweak a single phrase at a time so you know what actually moved the output.
4. State negatives positively: instead of "no blur", ask for "sharp focus, crisp details".
How much does it cost?
Pay-per-use in credits. A typical run costs about $0.030 ($1 = 100 credits); the exact price varies with parameters like resolution or duration, and the playground shows the exact quote before you submit.
Seedream V4
High-Fidelity Text-to-Image Generation with Advanced Layout Awareness
Seedream V4 by Bytedance is a cutting-edge text-to-image generation model optimized for creating high-resolution, layout-aware visuals. With its ability to produce consistent, high-fidelity outputs and support for resolutions up to 4K, this model is ideal for professional use cases such as social media assets, concept designs, and multi-panel posters. Enjoy seamless performance with no cold starts and affordable pricing.
🚀 Key Features
- Layout Awareness: Supports grid-based designs (e.g., 2×2 panels, triptychs, comics) with whitespace optimization for text placement, titles, and CTAs.
- High Fidelity: Delivers clean edges, strong identity retention, and minimal artifacts for professional-grade visuals.
- Resolution Flexibility: Default resolution of 2048×2048, with support for custom dimensions up to 8192×8192.
- Consistency Across Series: Maintains unified palettes, lighting, and camera settings across multi-panel designs.
- Affordable Pricing: Generate high-quality images for only $0.03 per run.
🛠️ Technical Specifications
| Parameter | Description |
|---|---|
| Model Architecture | Proprietary Bytedance Seedream V4 |
| Task Type | Text-to-Image |
| Input Format | Prompt (string) |
| Output Format | Image (PNG, JPG) |
| Default Resolution | 2048×2048 |
| Max Resolution | Up to 8192×8192 |
| Pricing | $0.03 per generation |
Sample Prompts
- Prompt: "A futuristic cityscape at sunset, with glowing neon signs and flying cars."
- Prompt: "A minimalist poster featuring a single red rose on a monochrome background."
- Prompt: "A 2×2 grid comic strip depicting a humorous conversation between two robots."
💰 Pricing
| Resolution | Price per Generation |
|---|---|
| Default (2048×2048) | $0.03 |
| Custom (Up to 8192×8192) | $0.03 |
FAQ
Can I try it for free first?+
Signup gives you free credits, but they currently apply only to selected in-app face-swap features — this model is pay-as-you-go. The playground still lets you try it without code, with the exact quote shown before you submit.
Can I use the output commercially? Is there a watermark?+
Yes, outputs are yours to use commercially, and NamiFusion adds no platform watermark — subject to the Terms of Service and applicable law.
What is the content policy?+
NamiFusion is an unfiltered engine: no arbitrary restrictions and NSFW-friendly, but illegal content and non-consensual use of real people are prohibited — see the Terms of Service.
How long does a Seedream V4 task take?+
It depends on parameters — images usually take seconds, videos tens of seconds to minutes. The API returns a task_uuid for polling.
What are the resolution and duration limits?+
See the parameter table above — each model lists its available resolution and duration options there and in the playground.