StabilityAI Suite - Outpainting

Outpainting is the "what's outside the frame" problem. You have a 1:1 image and you want a 16:9 version with the scene continued, or you want sky above a horizon, or room around a subject. Locally that means tiling, inpaint conditioning, and seam-matching - doable, but fiddly. This node hands the whole job to Stability's API: you say how many pixels to add on each side, it hallucinates the extension and blends it in.

How it works

A POST of the image plus four integers to stable-image/edit/outpaint. Each side takes 0–512 pixels per call. The response is a completed, larger image - no polling, no job ID. The model generates what's missing and mostly matches the original's lighting and texture where new content meets old edge.

Inputs that matter

• image - your starting frame.
• left / right / up / down - pixels to add per side, 0–512 each. This is where you actually spend time: the 512 cap is a hard limit per call.
• prompt - optional, but if you leave it empty the extension is whatever the model decides. Describing it ("cobblestone street continuing to the right") gives you far more control.

seed and output_format (png/webp/jpeg) round out the rest. Output is a single IMAGE.

Install

ComfyUI Manager, search "ComfyUI StabilityAI Suite", or manually:

cd ComfyUI/custom_nodes
git clone https://github.com/florestefano1975/ComfyUI-StabilityAI-Suite

Restart, set your key (SAI_API_KEY, sai_platform_key.txt, or the node's api_key_override). No models, no extra pip dependencies - the whole pack is a thin API wrapper.

Gotchas

• The 512px cap is real. To extend an image by a lot, run the node more than once, adding a few hundred pixels per pass and feeding the result back in. Each pass is a fresh paid call, and each pass can introduce a little drift at the seam - so going wide means checking your work between passes.
• Cost. Same story as the rest of the suite: this is a paid API, not a local model.
• Expect the biggest seams when the extension adds lots of new structure (perspective, furniture) rather than simple sky or floor, which the model blends almost invisibly.

If you outpaint constantly, a local FLUX.1 Fill / crop-and-stitch loop is the budget move. If you outpaint rarely and don't want a local inpainting stack eating VRAM and disk, this node is the pragmatic middle ground.