Comflowy Kling

Kling is Kuaishou's image-to-video model - the one that made waves for turning a single still into a coherent, physically sensible clip with real camera motion. It's closed, hosted, and this node puts it inside a ComfyUI workflow: image in, motion prompt in, video file out, with all the compute happening on Comflowy's servers. If you've been generating start frames locally and wishing you could animate them with a top-tier closed model without leaving the graph, this is the piece.

The README's pricing is unusually concrete here: Kling pro costs about 1250 credits per second of video, standard about 300 per second. A 5-second pro clip is over 6000 credits. That makes the version dropdown the most financially significant control on the node - standard for iterating, pro for the delivery.

How it works and the inputs

Standard Comflowy API pattern: the image is base64-encoded and POSTed with your settings, the server runs the Kling generation, and the result is downloaded to your output folder as an .mp4. The VIDEO output is a file path string, not a preview - so, like the other video nodes in this pack, you need the Comflowy Preview Video node wired to it or you'll be hunting for the file in your output directory.

• image (required) - the start frame.
• prompt (required, multiline) - describe the motion, not just the scene. "The camera slowly orbits while the subject waves" beats "a person."
• version - standard or pro. The 4x price difference is the quality/credit trade.
• aspect_ratio - 16:9, 9:16, or 1:1. No custom sizes here.
• duration - 5 or 10 seconds. Directly multiplies your credit spend.
• seed - 0 to 2^31-1.

Output: video (VIDEO type).

Installing and the failure modes

Install Comflowy's Custom Nodes via ComfyUI Manager (search "Comflowy") or git clone https://github.com/6174/comflowy-nodes into custom_nodes, restart, set your key with Comflowy Set API Key. Dependency: requests. Nothing downloads locally - no weights, no models, no VRAM.

The gotchas, grounded in how the pack actually behaves:

• error.mp4 in your output folder is a failure, not a video. The pack's base class returns a placeholder error.mp4 path when an API call fails. If you see it, the real error is in your ComfyUI console - typically a network problem or a key issue. The README singles out connectivity as the top cause of failures across all these nodes.
• Credits scale with duration. 10 seconds at pro is the most expensive single node action in this pack. Start at 5 seconds standard to validate the motion, then commit.
• Preview Video is mandatory. Without it, nothing displays the clip; the node isn't an output node on its own.

Honest take: if you're already happy with open video models like Wan that you can run locally, Kling's hosted motion quality is a convenience, not a necessity - and the per-second billing punishes iteration. Where it wins is the "I have one great still and I need a professional-looking clip" moment on a machine that can't run video models at all.