EvoLink Seedance 2.0 Text-to-Video (Official)

Seedance is ByteDance's video model, and ByteDance plays a specific game: the flagship generation products stay API-only, forever, while the components underneath go open. You'll never download Seedance - the whole Seedream/Seedance line is a closed API product by design. So the moment this model appeared in ComfyUI as an API node, the community had two very loud reactions: excitement that it's reachable at all, and a hard "go kick rocks" from the local-only crowd over what a subscription costs. Both reactions are right. EvoLink Seedance 2.0 Text-to-Video (Official) is the door; the meter is the price of the door.

What it does

Prompt to video, 4 to 15 seconds, up to 4K, with synchronized audio generated for free - the generate_audio toggle defaults to on and the tooltip is explicit that it doesn't add to the bill. That's a real differentiator; most video APIs charge extra for sound or don't do it at all.

The inputs that matter:

• prompt (required) - the shot description, Chinese welcome (the tooltip suggests keeping it under ~500 characters for best results).
• duration - 4–15 seconds, default 5, billed by duration.
• quality - 480p / 720p / 1080p / 4k. 480p is the cheap lane; 4k is where the per-render price starts to really bite.
• aspect_ratio - adaptive by default (the model picks), or 16:9, 9:16, 1:1, 4:3, 3:4, 21:9.
• generate_audio - on by default, costs nothing extra. Turn it off for pure silent drafts if you want.

Outputs: video (downloaded - connect a Save Video node or you'll see nothing), task_id, status_info (elapsed time and credits used), result_urls (24-hour expiry), response_json.

Install and key

Shared EvoLink install. ComfyUI Manager → search EvoLink → install → full restart (close the console window, not just refresh the browser). Manual:

cd ComfyUI/custom_nodes
git clone https://github.com/deeplearning-goethe/comfyui-evolink

Only requests as a dependency; no models, no GPU. Key from evolink.ai/dashboard/keys (sk-), pasted once into api_key - saved locally, blank after, never in a shared workflow JSON.

The honest economics

Seedance via API is the canonical example in this space of "it's extremely expensive" - the community's own math: a small number of videos per year on a $20–30/month subscription. The counterpoint is just as true: that's the real price of these renders; free/cheap was the loss-leader phase. So use this node the way you'd use a paid render farm: it's for the videos you need that you can't get locally, not for spraying drafts. The default 1800-second (30-minute) timeout tells you something about how long a real video job takes - it's a "start it, go make tea, come back" node, not a "waiting for it is the fun part" node. Unchanged params cache and don't re-bill, and failed or moderation-blocked tasks don't charge, which softens the ouch. But the ouch is real: every render is a line item.