# Seedream 4.0 in ComfyUI: How to Build an API Image Workflow

> Published 2026-04-03, updated 2026-09-05 · https://www.promptzone.com/rohan_moreau/seedream-4-enhances-ai-image-generation-5f11

---
title: "Seedream 4.0 in ComfyUI: How to Build an API Image Workflow"
published: true
description: "Run Seedream 4.0 through the documented ComfyUI Partner Node, connect reference images, and check account, size, and output settings."
tags: ai,comfyui,imagegeneration,seedream
---
To use Seedream 4.0 in ComfyUI, sign in with a Comfy account, add credits, and select `seedream-4-0-250828` in `ByteDanceSeedreamNode`. The node calls ByteDance Seed's hosted model. [Node source][nodecode], [Partner guide][partners]

## What are the key facts about Seedream 4.0 in ComfyUI?

| Fact | Verified detail |
| --- | --- |
| Developer | ByteDance Seed. [Announcement][launch4] |
| Released | September 9, 2025; ComfyUI integration recorded September 10, 2025. [Announcement][launch4], [Changelog][changes] |
| Type | Hosted image generation and editing through an API node. [Node reference][node4] |
| Size or parameters | Not published on the official product page. [Product page][product4] |
| License and access | No open Seedream weights supplied; Partner Node access uses Comfy account credits. [Product page][product4], [Partner documentation][partners] |
| Where it runs | The workflow runs in ComfyUI; Seedream inference runs on the external service. [Partner documentation][partners] |

## What can the Seedream 4.0 ComfyUI node do?

The Seedream node accepts a prompt and optional reference images, then returns an `IMAGE` output. This gives you a documented connection between hosted generation and an image workflow. [Node reference][node4]

A useful first graph has a single generation stage and a saved output. Keep the graph small while you learn which settings belong to the node and which belong to your later processing steps.

For an editing trial, start with one photograph and a visible change. Ask for a different background while retaining the subject's pose, then compare the result with the original before adding another transformation.

The node also exposes sequential generation for related outputs. Decide whether you need one image or a related set before running the graph, and inspect the corresponding controls. [Node reference][node4]

ComfyUI documents combining Partner Node results with local image-processing nodes. Review each stage to identify whether an unwanted change came from generation or later processing. [Partner documentation][partners]

## What does the Seedream Partner Node require?

Partner Nodes require a Comfy account, credits, and network access. A graph containing a Seedream API node therefore depends on the hosted service even when ComfyUI itself is on your machine. [Partner documentation][partners]

The Seedream node's custom width and height controls apply only when its size preset is set to `Custom`. Prefer a documented preset for the initial connection test. [Node reference][node4]

Do not assume that a control exposed by another image node has a Seedream equivalent. Use this node's own schema to decide which inputs can be changed. [Node reference][node4]

The documentation includes a `fail_on_partial` option for handling missing or unsuccessful images in a requested set. Check that behavior before attaching downstream work that expects every requested image. [Node reference][node4]

Keep a saved copy of the smallest working graph. When something breaks after you add a stage, compare the new graph with that baseline before changing unrelated settings.

Separate access errors from visual problems during review. A rejected request requires inspecting the service response; an off-brief image requires inspecting the prompt, references, and acceptance criteria.

## How do you set up Seedream 4.0 in ComfyUI?

1. Update ComfyUI if the Seedream node is missing. Its official changelog records the integration, and the Partner Node guide recommends checking version differences. [Changelog][changes], [Partner documentation][partners]

2. Open `Settings`, then `User`, and sign in to your Comfy account. Check the balance in `Credits` before submitting the workflow. [Partner documentation][partners]

3. Add `ByteDanceSeedreamNode`, displayed as **ByteDance Seedream 4.5 & 5.0**. Select `seedream-4-0-250828`, enter a simple prompt, and keep sequential generation disabled. [Node source][nodecode]

4. Connect the node's image output to a Save Image node, run the workflow, and inspect the saved result. [Seedream node][node4], [Save Image node][save]

5. For an edit, connect a loaded reference image to the optional `image` input and change the prompt to describe the requested transformation. [Node reference][node4]

For example, propose an interior edit: replace a patterned rug with a plain beige rug while preserving the furniture, windows, and camera position. Check those preserved elements before accepting the image.

For a direct API connection test, use this BytePlus request structure. This uses a **ModelArk key**, independently of the Comfy account used by the built-in Partner Node. [API tutorial][api], [Partner documentation][partners]

```bash
curl --fail-with-body https://ark.ap-southeast.bytepluses.com/api/v3/images/generations \
  -H "Authorization: Bearer $ARK_API_KEY" \
  -H 'Content-Type: application/json' \
  -d '{
    "model": "seedream-4-0-250828",
    "prompt": "A quiet reading room with a beige rug, a wooden chair, and soft daylight.",
    "size": "2K",
    "response_format": "url"
  }'
```

Use the [direct Seedream API guide][direct] when building an application around ModelArk. Success through that route checks those credentials and that endpoint; it does not establish that Comfy account access is configured.

When a node is unavailable, check your installed version and whether Partner Nodes are disabled. When it is present but fails, inspect login, credits, connectivity, and the returned error. [Partner documentation][partners]

After the basic graph works, save an accepted output before experimenting with more references or additional processing. Keep a note of each added stage and the specific problem it is meant to solve.

## How does the Seedream node compare with a local FLUX workflow?

| Workflow | Generation location | Setup focus |
| --- | --- | --- |
| Seedream 4.0 Partner Node | External API service. [Partner documentation][partners] | Account access, node inputs, and returned images. |
| FLUX.2 [dev] in ComfyUI | Downloadable model supports local use. [Model card][fluxdev] | Model files, deployment configuration, and applicable license. |

Use the [ComfyUI complete guide][pillar] for the surrounding workflow concepts. Compare the operating arrangement first, then evaluate image quality using your own references and prompts.

## What else should you know about Seedream 4.0 in ComfyUI?

### Is Seedream running locally inside ComfyUI?

Seedream 4.0 inference runs on an external service when called through its ComfyUI Partner Node. Running the graph locally does not download Seedream model weights. [Partner documentation][partners]

### Why do my custom dimensions have no effect?

In `ByteDanceSeedreamNode`, width and height apply when `size_preset` is `Custom`. Check that setting before changing the dimension values again. [Node reference][node4]

### Can I use a reference photograph?

Yes, `ByteDanceSeedreamNode` accepts a reference photograph through its optional `image` input. Start with a single image and a precise edit so you can judge whether the requested change was made. [Node reference][node4]

### Where should I look when generation fails?

For a failed Seedream Partner Node request, inspect the error and check Comfy account login, credits, and network access. Re-run the smallest working graph before investigating later processing stages. [Partner documentation][partners]

[direct]: /joaquin_liu/seedream-4-boosts-ai-image-generation-3d67
[pillar]: /tomas_novak/comfyui-2026-the-complete-guide-to-power-user-ai-image-generation-1g17

## Sources

- [ComfyUI Seedream node implementation](https://raw.githubusercontent.com/Comfy-Org/ComfyUI/master/comfy_api_nodes/nodes_bytedance.py)

- [ByteDance Seedream 4.0 announcement](https://seed.bytedance.com/en/blog/seedream-4-0-officially-released-beyond-drawing-into-imagination)
- [ByteDance Seedream 4.0 product page](https://seed.bytedance.com/en/seedream4_0)
- [ComfyUI Seedream node reference](https://docs.comfy.org/built-in-nodes/ByteDanceSeedreamNode)
- [ComfyUI Save Image node reference](https://docs.comfy.org/built-in-nodes/SaveImage)
- [ComfyUI Partner Nodes documentation](https://docs.comfy.org/tutorials/partner-nodes/overview)
- [ComfyUI changelog](https://docs.comfy.org/changelog)
- [BytePlus image generation tutorial](https://docs.byteplus.com/api/docs/ModelArk/1824121)
- [Black Forest Labs FLUX.2 dev model card](https://huggingface.co/black-forest-labs/FLUX.2-dev)

[launch4]: https://seed.bytedance.com/en/blog/seedream-4-0-officially-released-beyond-drawing-into-imagination
[product4]: https://seed.bytedance.com/en/seedream4_0
[node4]: https://docs.comfy.org/built-in-nodes/ByteDanceSeedreamNode
[save]: https://docs.comfy.org/built-in-nodes/SaveImage
[partners]: https://docs.comfy.org/tutorials/partner-nodes/overview
[changes]: https://docs.comfy.org/changelog
[api]: https://docs.byteplus.com/api/docs/ModelArk/1824121
[fluxdev]: https://huggingface.co/black-forest-labs/FLUX.2-dev

[nodecode]: https://raw.githubusercontent.com/Comfy-Org/ComfyUI/master/comfy_api_nodes/nodes_bytedance.py

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