ComfyUI

Install the Liquid nodes in ComfyUI, save your key one time, and buy images or video inside a workflow. Each paid node has a price cap on each run.

Node	What it does	What you pay for
Liquid Image (paid API)	Sends the prompt to `/v1/images/generations`.	The images returned.
Liquid Video (paid API)	Sends the prompt to `/v1/videos` and waits for the job.	Each second of the video.
Liquid Video Job	Gets the video of a job again.	Nothing. It makes no new charge.

Before you start

A workspace with a balance and a spend key. See API keys.
ComfyUI 0.3.45 or newer, with ComfyUI-Manager. The desktop app includes the Manager.

1. Install the node

Open Manager, then Custom Nodes Manager. Search for this name and install it:

Liquid Inference

Restart ComfyUI. With comfy-cli, use this command:

comfy node install liquid-inference

The source is architect-xyz/comfyui-liquid-inference.

2. Set the key

Open Settings, then Liquid Inference. Paste the key into API key and click Save:

sk-liquid-...

The nodes have no key input, because ComfyUI writes input values into the metadata of each saved image. The server keeps the key in a file that only your system user can read.

On a server without a browser, set LIQUID_API_KEY before you start ComfyUI. The variable has priority over the saved key.

3. Buy images

Double-click the canvas and search for Liquid Image.
Write a prompt, and select a model and a cap.
Connect images to Save Image.

The node also gives the job ID and a short receipt as text.

model lists the image models on the book. The node refreshes the list each minute.
size lists the sizes that at least one offer declared. With auto, the node sends no size and each seller uses its default. An explicit size goes only to the offers that declared it.

4. Buy a video

Double-click the canvas and search for Liquid Video.
Write a prompt, and select a model and a cap.
Connect video to Save Video.

Templates has examples for both nodes.

model lists the video models on the book.
size and seconds list the values that at least one offer declared. With auto, the node sends no field. For seconds, the exchange then uses the shortest length that an offer declares. The charge is the price of that length.
retention defaults to none, which excludes providers that can keep your content. Select allowed only if the provider can keep your prompt, start image and video.
start_image starts the video from an image. The node sends the first image of the batch as a PNG in input_reference. Only a model that reads image input can take it. Use an image with the shape of the size, because a seller can crop a different shape.

How the wait works

The node reads the job status every 5 seconds and waits 30 minutes at most. It then gets the file from /v1/videos/{id}/content. It tries a failed status read or download again, because these buy nothing.

A stop in ComfyUI stops the wait, not the job. The exchange cannot cancel a video job and charges for it when it is complete. To get the video, paste the job ID into a Liquid Video Job node. The seller keeps the file until expires_at in the receipt.

Base URL

To use a different exchange, set Base URL in Settings → Liquid Inference, or set LIQUID_BASE_URL:

https://router.inference.ai.exchange/v1

Limits and notes

The cap limits each run of a node, not a workflow or a queue. Three Liquid nodes with a cap of $0.05 can cost $0.15 for each run. To limit total spend, set a spending limit on the key. See API keys.
A paid node never sends a purchase again by itself. If the connection stops, the error gives the Idempotency-Key, so you can find the job on the Receipts page.
The prompt goes to the seller that wins the auction. It can be a different company for each run.

Troubleshooting

Symptom	Cause and fix
`No Liquid Inference API key`	Save the key in Settings → Liquid Inference, or set `LIQUID_API_KEY` and restart ComfyUI.
`401`	The key is empty, wrong or expired. Save it again.
`402 insufficient_balance`	Add credit, or check the spend limit of the key.
`400 unsupported_parameter`	No offer for the model takes the value in `param`, usually `size`. Set size to `auto`.
`503` with `cap_exceeds_buyer_cap`	Each offer costs more than the cap. Increase cap_usd, or the spend limit of the key.
`503 model_unavailable`	The model has sellers, but none can take a job now. Try again in a minute, or select a different model.
`503 provider_failed`	The seller failed before it made an image. You were not charged. Queue again. A run 30 seconds later can go to the same seller.
`410 video_expired`; the error says the outcome is unknown	The seller deleted the file; or the connection stopped. Look for the job on the Receipts page before you queue again.
A video job failed	The seller did not make the video. You were not charged. Queue again, or select a different model.
The node stopped waiting for a video	The job continues and is charged. Paste the job ID into a Liquid Video Job node.

See Errors for all error codes. See also Modalities and Video generation.