KIE Seedance 1.5 Pro (I2V/T2V) [SL]

ByteDance's Seedance is one of the closed video models people measure the open ones against, and this single node covers both of its modes. Wire an image in and it's image-to-video; leave images disconnected and the same node runs pure text-to-video. One node, two jobs, no second install.

That duality is the honest selling point. In a storyboard pipeline you'll want I2V to animate your keyframes and T2V for establishing shots you can't source a still for - and rather than juggling two different nodes, you just connect or disconnect the images input. The node even tells you which mode it's running in, logging "running in text-to-video mode" when no images arrive.

The inputs that matter

• prompt - required, at least 3 characters, up to 2500.
• images - optional, and it's the first two that get used (Seedance 1.5 Pro can take a start-frame pair). More than two and the extras are ignored.
• aspect_ratio - 1:1, 21:9, 4:3, 3:4, 16:9, or 9:16.
• resolution - 480p or 720p. Cheaper drafts at 480p, deliverable at 720p.
• duration - 4, 8, or 12 seconds. Note: 12s is longer than most nodes in this pack offer.
• fixed_lens - locks the camera lens during generation. On for stable shots, off if you want camera freedom.
• generate_audio - off by default, and the HELP text flags it: enabling it costs extra. Seedance can synth audio to match the clip, but you pay for it.

Output is video, a ComfyUI VIDEO object you save with SaveVideo.

How it works

Standard KIE async job: upload up to two reference images, create a task for the bytedance/seedance-1.5-pro model, poll until the clip renders, download the MP4, return it as a VIDEO. Transient 429/5xx errors retry automatically with backoff. Video renders default to a 1000-second timeout floor, so a 12-second clip at 720p can legitimately take a while.

Install

The pack installs once and every node appears together:

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

or Manager search "Kie-API-Serverless", restart. No model downloads; just your KIE key in the node input.

Where people get burned

Duration and resolution are where the bill lives - 12 seconds at 720p is the expensive end, and audio adds on top. Also keep expectations honest about the closed-model moderation: Seedance is a ByteDance product and refuses what ByteDance refuses; the node can't bypass that. And the usual pack gotcha applies - this is a serverless fork, so the API key rides in the saved workflow JSON. Scrub it before sharing a workflow.