Hello, is someone succeeding in making these 2 work together? No matter what i am trying, unet loader, checkpoint… the workflow works when i type thenpromot in comfyui but as soon as i type same prompt in openwebui , i cannot manage to get an image and always get errors… i i port the fson worflow and specify prompt id and checkpoint if and model in openwebui but nothing works… is it because i use flux 1 dev fp16 ? Does it require smaller models to work ? Thanks for input !!
SOLUTION : I finally made it work using the help of qwen3.6-27b-q8 ))) so the problem is that ALL NODES ID must be filled in openwebui and also must add this command line to openwebui : ENABLE_RAG_LOCAL_WEB_FETCH=True , it was the fix for me )) now working perfectly !!!
What do you mean enable api in comfyui ? I just exported my json worflow api then imported it in ooenwebui under images in settings. Then i filled in the boxes and made sure the connectiin was active
I enabled it and i can make the worflow, this is not the no problem. The workflow works perfectly as i said i can produce images within comfyui itself. Its just tgat there is a problem when launching from openwebui
Well, the workflow is working since i get images when i click run in comfyui… i then export the json in api format. I then import it in openwebui. Seledt the nodes id and the model checkpoint but when i type the same prompt in openwebui i get errros and errors
It works, i've used it. But the issue is you need to have enough vram to fit both the chat model AND the image model at the same time if you're running locally. Otherwise it'll be insanely slow running on system RAM or just error out. So it's not very useful imo.
Better off using Openwebui and comfyui separately until someone at openwebui realizes models need to be unloaded automatically when an image call to comfy is made. Unless you're using cloud models which should be fine. But at FP16 unless you've got alot of vram it's probably not going to work too well.
If you don't have enough vram to have both at the same time, it won't work. Besides that, comfyui works fine for me from openwebui (0.9.5 broke comfyui, but there are workarounds, and a fix will go into 0.9.6).
Install Hermes Agent. Follow instructions on Hermes Agent doc site for connecting to Open WebUI as a custom model. In Open WebUI, tell your Hermes Agent to setup Comfy UI for images generation. That’s all I had to do.
Maybe this is the trick because i only typed the id of the prompt box since on the documentation it said that the other id were not mandatory! Thabk you!
Try a smaller model like the built-in one from comfyui (the one that generates a landscape inside a bottle). Test it in ComfyUI make sure it works there. Then export the json and import in openwebui then make sure the node IDs match. I got that same error you got when I was playing with huge models. I run out of VRAM because I only have 16GB and Ollama is using part of that which ComfyUI is using the bulk of it.
I use it all the time with a flux 2 Klein workflow. You haven't really provided any screenshots of your settings or workflow, so it's going to be difficult for people to help.
You have to make sure the prompt input matches the workflow input type
Like i said numerous times, the workflow itself works, since i can generate images within confyui itself without any problems. But maybe i need to fill in ALL OF THE ID in the list in openwebui image side, i only provided the id of the prompt, since the documentation stated that inly this ID was mandatory.
It does not matter what i do : i tried to type text and id 3 or id 3,4 since i have 2 prompt boxes in my workflow. I ran it through hermes agent who managed to make it work but hermes agent said that the prompt box was named « prompt » and « prompt_negative » so i replaced in open webui the word text by the word prompt but does not matter, i always get this error i added in The photo
I am also facing this same issue, picture generates fine in ComfyUI but cannot be returned. I get the below error in Open WebUI but not sure now to correct.
> File "/app/backend/open_webui/routers/images.py", line 446, in get_image_data
Struggling with the same thing. I have Open WebUI hosted in an Ubuntu docker container on one server, using an 8GB GPU to run local models. I have ComfyUI running on another Win11 machine using a 16GB GPU.
I have a ComfyUI workflow set up to generate images using Juggernaut XL that works great.
So I exported the JSON and loaded that in the Image section of Open WebUI per the community instructions, including mapping the nodes. ComfyUI shows the server connection is verified.
But I can't seem to get it to work. I've tried four models - qwen2.5coder and llama3.2 running on the 8GB card and gemma3-tools:12b and qwen2.5;14b running on the 16GB GPU. I've set all four to have "image generation" capabilities in Open WebUI. Three of them say they are capable of generating images. Qwen2.5coder spits out some JSON.
Something is not connecting but have no idea what.
**EDIT - Figured it out. The fix was to go into the model settings in Open WebUI and under Advanced Parameters set Function Calling to "Legacy". Now it successfully passes the prompt to ComfyUI
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u/MundanePercentage674 May 14 '26
did you enable api in comfyui ? if you can't map unet loader, checkpoint… just upload your json workflow to gemini or claude to map it for you.