Seedance 2.0 brings a boundary‑conditioned approach to video generation: supply the first and last frames, and the model synthesizes the in‑between motion with striking temporal stability. Instead of guessing a trajectory from a single image or relying on text prompts, the pipeline conditions on both endpoints to infer a coherent path for objects, lighting, and camera movement. In ComfyUI, this is encapsulated by the ByteDance2FirstLastFrameNode, which takes two images and produces a full sequence that faithfully lands on your final frame.
This first‑last‑frame to video (FLF2V) method reduces identity drift, flicker, and composition shifts that commonly plague single‑frame or text‑to‑video methods. Unlike basic frame interpolation—which can only warp what already exists—Seedance 2.0 synthesizes novel content between your keyframes while preserving structure and intent. The result is cleaner motion planning, stronger subject consistency, and more predictable outcomes for real productions.
API
Use this workflow from code
Every Comfy workflow is a JSON graph. The payload below is this workflow, exactly as ComfyUI runs it — fetch it from the URL, keep it in version control, or load it in ComfyUI and run it node by node.
Run it from TypeScript or Python with the Comfy SDK. The same code targets Comfy Cloud or a ComfyUI you host yourself — only the base URL changes.
// Install (beta)
npm i @comfyorg/sdk
// Run "Seedance2.0: First-Last-Frame to Video" (TypeScript)
import { Comfy } from "@comfyorg/sdk";
const client = new Comfy({ apiKey: "comfyui-..." });
// This workflow, exported in API format (see note below)
const wf = await client.workflows.fromFile("api_seedance2_0_flf2v_api.json");
const asset = client.assets.fromFile("input.png");
wf.setInput("3", "image", asset); // LoadImage
const job = await client.run(wf);
await job.getOutputs("2")[0].toFile("output.png"); // SaveVideoThe SDK takes a workflow in API format: open this workflow in ComfyUI and use File → Export Workflow (API).
Comfy Cloud API access requires a plan with an API key.
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