KIE Seedream 4.5 Edit [SL]

The edit member of ByteDance's Seedream 4.5 image family. You hand it an existing image and an instruction - "swap the background to a rainy city street," "turn this product shot into a studio setting" - and it rewrites the image to match, keeping everything you didn't mention intact. This is the node for changing a photo or a generated still without regenerating it from scratch.

In a ComfyUI pipeline this slots in right after generation: you made a 3x3 grid with Nano Banana or Seedream, sliced it with GridSlice, and now you want each tile tweaked - relight this one, change the outfit on that one. Seedream 4.5 Edit is the per-cell rework pass. The alternative would be regenerating each image with a modified prompt, which is a lottery ticket compared to "keep this, change that."

The inputs that matter

• images - required. First image in the batch wins, extras are ignored.
• prompt - the edit instruction, up to 3000 characters. Say what changes, not what everything should look like; Seedream holds the original for you.
• aspect_ratio - 1:1, 4:3, 3:4, 16:9, 9:16, 2:3, 3:2, 21:9. Pick the output canvas.
• quality - basic or high. Basic for iteration, high for the keeper.

Output is a single image tensor, ready for SaveImage or any downstream node.

How it works

The standard KIE job machinery: upload the source image as PNG, create an async task for seedream/4.5-edit, poll until it finishes, download and decode the result. Transient 429/5xx errors retry automatically with backoff. Because the input image uploads every run, edits cost slightly more than a bare text-to-image call - and they add up fast if you're doing 20 tiles.

Install

Same as the rest of the pack:

cd ComfyUI/custom_nodes
git clone https://github.com/v3devv/ComfyUI-Kie-API-Serverless

or ComfyUI Manager search "Kie-API-Serverless", then restart. No models to download; just your KIE key in the node field.

Where people get burned

Edit models are literal about their limits. "Add a cat" usually works; "completely restyle this in the style of X while keeping the composition identical" is a stretch, and Seedream is a closed ByteDance model so it refuses what ByteDance refuses. Iterate on basic quality before spending high credits. And the classic trap: if you change the aspect_ratio on an edit, you're asking the model to re-compose, not just patch - keep it matching the source unless you actually want a new frame.