ComfyUI-S3-IO

S3-backed input/output nodes for ComfyUI. It lets you browse/load images and videos from an S3 (or S3-compatible)

bucket, upload local input files to S3, and push outputs back to S3 automatically.

Features

Load images and videos directly from S3 input prefixes.

Upload local input files (and pasted/dragged files) to S3 on demand.

Save image outputs and video renders back to S3 output prefixes.

Optional custom S3 endpoint for MinIO/compatible storage.

Thumbnail generation for fast image previews.

Light caching for downloaded objects.

Installation

Clone or copy this folder into your ComfyUI custom nodes directory:

ComfyUI/custom_nodes/ComfyUI-S3-IO

Install dependencies in your ComfyUI Python environment:

python -m pip install -r requirements.txt

Set the required environment variables (see below) and start ComfyUI.

Configuration

Required:

S3IO_ACCESS_KEY_ID

S3IO_SECRET_ACCESS_KEY

S3IO_BUCKET

Optional:

S3IO_ENDPOINT_URL (for MinIO or other S3-compatible endpoints)

S3IO_REGION

S3IO_INPUT_PREFIX (default: empty)

S3IO_OUTPUT_PREFIX (default: empty)

S3IO_THUMB_PREFIX (default: thumbs)

Legacy environment prefix S3_ is also supported (e.g., S3_ACCESS_KEY_ID).

Example:

export S3IO_ACCESS_KEY_ID="AKIA..."
export S3IO_SECRET_ACCESS_KEY="..."
export S3IO_BUCKET="comfy-bucket"
export S3IO_ENDPOINT_URL="https://s3.example.com"
export S3IO_REGION="us-east-1"
export S3IO_INPUT_PREFIX="inputs"
export S3IO_OUTPUT_PREFIX="outputs"
export S3IO_THUMB_PREFIX="thumbs"

Nodes

Load Image from S3

Lists files from S3IO_INPUT_PREFIX with image extensions.

If the selected file exists locally (ComfyUI input directory), it is uploaded to S3 and used.

Otherwise the file is downloaded to a local cache and loaded.

Save Image to S3

Saves the image locally (same as the stock node) and uploads to S3IO_OUTPUT_PREFIX.

Ensures unique filenames on S3 (adds (n) suffixes if needed).

filename_prefix supports the standard replacements (%date:yyyy-MM-dd%, %OtherNode.widget%, etc.) just like the stock Save nodes.

Load Video (Upload) from S3

Lists files from S3IO_INPUT_PREFIX with video extensions.

Same upload/download behavior as the image node.

Uses the vendorized VideoHelperSuite load path.

Video Combine to S3

Extends VideoHelperSuite output and uploads all generated files to S3IO_OUTPUT_PREFIX.

Adds UI download entries so ComfyUI can prompt for downloads.

filename_prefix accepts the same replacements (%date:...%, %SomeNode.widget%) as VHS_VideoCombine.

Example prefix:

%date:yyyyMMdd%/run_%PositivePrompt.text%

This saves under a date-based subfolder and inserts another node’s widget value, matching the behavior of the built-in save nodes.

UI Upload/Download Integration

Adds upload buttons and drag-and-drop/paste support for Load Image from S3 and Load Video (Upload) from S3.

Adds a delete button to remove the currently selected S3 input file (with confirmation prompt).

Also hooks into VHS_LoadVideo / VHS_LoadVideoFFmpeg if those nodes exist.

If comfyuiDL is available, output downloads are requested automatically.

Notes

S3 listings are refreshed when you use ComfyUI’s Refresh (Refresh Node Definitions).

Download cache lives under ComfyUI temp as temp/s3-io/... and respects S3 ETag changes.

Thumbnails are stored in S3IO_THUMB_PREFIX as .jpg (max 256px).

Image previews fetch S3 thumbnails (or originals) into temp when the file is not present locally.

Video previews fetch S3 files into temp when the file is not present locally.