Seedance 2.0 Multiframe Stitch is a ComfyUI workflow for generating smooth in-between frames between two key images, then assembling them into a video. At its core is the ByteDance2FirstLastFrameNode, which uses the Seedance 2.0 model to synthesize a sequence that transitions from your first frame to your last. This makes it ideal for rapid iteration, motion studies, and quick inbetweening without writing code or handling external tools. Note: running Seedance 2.0 can be credit-intensive, so plan your frame count and resolution accordingly.
Technically, the workflow starts by loading your start and end images with LoadImage. Those images are passed into ByteDance2FirstLastFrameNode to generate a multiframe batch of interpolations. ImageBatch ensures the frames are properly grouped for video creation. GetVideoComponents can be used to set or match video properties (such as frame rate) if you are aligning to a reference. Finally, CreateVideo assembles the frame batch into a video stream, and SaveVideo writes the result to disk. The result is a stitched, coherent transition clip built entirely from two stills.
What makes this useful is the combination of controllability and speed: you pick the anchor frames, the node interpolates the motion, and the rest of the graph reliably compiles and saves the output. Keep both input images the same resolution and aspect ratio for best results, and manage cost by reducing frame count, resolution, or iterations if exposed in your node configuration.
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 this workflow (TypeScript)
import { Comfy } from "@comfyorg/sdk";
const client = new Comfy({ apiKey: "comfyui-..." });
const wf = await client.workflows.fromFile("workflow_api.json");
const job = await client.run(wf);
await job.getOutputs("<output-node-id>")[0].toFile("output.png");The 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.
FAQ
