# 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](https://inference.ai.exchange/docs/keys.md). - 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: ```bash comfy node install liquid-inference ``` The source is [architect-xyz/comfyui-liquid-inference](https://github.com/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 1. Double-click the canvas and search for **Liquid Image**. 2. Write a prompt, and select a model and a cap. 3. 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 1. Double-click the canvas and search for **Liquid Video**. 2. Write a prompt, and select a model and a cap. 3. 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](https://inference.ai.exchange/docs/keys.md). - 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](https://inference.ai.exchange/docs/errors.md) for all error codes. See also [Modalities](https://inference.ai.exchange/docs/modalities.md) and [Video generation](https://inference.ai.exchange/docs/video-generation.md).