SeedEdit Node

SeedEdit Node is a one-node trip to ByteDance's cloud. You feed it an image and an instruction, it calls the doubao SeedEdit 3.0 image-edit model through Volcengine's Ark API, and a few seconds later you get back the edited image as a normal ComfyUI IMAGE tensor. No local GPU, no model weights, no VRAM - the entire model lives in ByteDance's data center, and that's the whole personality of this node.

SeedEdit is real, by the way. It's ByteDance's image-revision model (the Doubao team's answer to "change this picture without regenerating it"), and it's exactly the kind of thing the KB's ByteDance panel describes: flagship products stay API-only, closed weights, no open release. So the trade is straightforward - you skip the hardware and the setup, and in exchange your images leave your machine and you pay per call. Compare that to the open instruction editors like Qwen-Image-Edit or Flux Kontext, which you'd run locally.

How it works

The node does three things under the hood: it converts your input image to a base64 PNG data URL, calls client.images.generate(...) with your prompt and settings, then downloads the returned image URL and converts it back to a ComfyUI tensor. That client is the load-bearing piece - it's an ARK_CLIENT, and you have to build one first with the pack's CreateArkClient node. The client wants an API key from a Volcengine Ark (火山方舟) account, either typed into the node or set as the ARK_API_KEY environment variable. No key, no client, and the client node errors loudly about it.

Inputs and outputs

• client (ARK_CLIENT) - from CreateArkClient, your authenticated session.
• image (IMAGE) - the photo to edit. Only the first frame of a batch is used.
• prompt (STRING, multiline) - the edit instruction. The default is Chinese ("make it into a heart-shaped bubble"), which is a hint about the pack author's audience - but you can write English or whatever the model handles.
• seed (INT, default 123) - for reproducible edits.
• Optional: model (single choice: doubao-seededit-3-0-i2i-250628), size (default adaptive), guidance_scale (0–20, default 5.5 - how hard it follows the prompt), watermark (boolean, default true).
• Output: IMAGE, the edited result.

That watermark default is worth a look. ByteDance embeds a visible watermark unless you flip it off - remember it's on, because it's the kind of thing you notice a hundred images later.

Troubleshooting

• ImportError about volcengine. The Ark SDK is one of the pack's dependencies; if your ComfyUI environment didn't pick it up, pip install volcengine-python-sdk[ark] fixes it.
• 400 errors. This is the real, documented failure mode. The community has threads about SeedEdit 3.0 suddenly throwing 400s - providers quietly retiring the old version in favor of Seedream 4.5 Edit and the like. If you start getting 400s out of nowhere, it may not be your config; the model string may simply no longer be current. Check your key and region first, then check whether doubao-seededit-3-0-i2i-250628 is still a valid Ark model.
• The node re-raises API exceptions, so errors surface in the ComfyUI UI instead of silently producing garbage - a small mercy, and not something every API node bothers with.

Install

ComfyUI Manager → search Duanyll Nodepack → install → restart, or:

cd ComfyUI/custom_nodes
git clone https://github.com/Duanyll/duanyll_nodepack

Setup beyond that is one account on Volcengine Ark, one API key, and a few cents in your wallet. The README won't walk you through it - it's scaffolding - but the CreateArkClient node's own error messages are honest about what's missing.