[GH-ISSUE #18295] issue: Display custom error messages

Originally created by @VRivi on GitHub (Oct 13, 2025). Original GitHub issue: https://github.com/open-webui/open-webui/issues/18295 ### Check Existing Issues - [x] I have searched for any existing and/or related issues. - [x] I have searched for any existing and/or related discussions. - [x] I am using the latest version of Open WebUI. ### Installation Method Docker ### Open WebUI Version v0.6.33 ### Ollama Version (if applicable) _No response_ ### Operating System windows 11 ### Browser (if applicable) _No response_ ### Confirmation - [x] I have read and followed all instructions in `README.md`. - [x] I am using the latest version of **both** Open WebUI and Ollama. - [x] I have included the browser console logs. - [x] I have included the Docker container logs. - [x] I have **provided every relevant configuration, setting, and environment variable used in my setup.** - [x] I have clearly **listed every relevant configuration, custom setting, environment variable, and command-line option that influences my setup** (such as Docker Compose overrides, .env values, browser settings, authentication configurations, etc). - [x] I have documented **step-by-step reproduction instructions that are precise, sequential, and leave nothing to interpretation**. My steps: - Start with the initial platform/version/OS and dependencies used, - Specify exact install/launch/configure commands, - List URLs visited, user input (incl. example values/emails/passwords if needed), - Describe all options and toggles enabled or changed, - Include any files or environmental changes, - Identify the expected and actual result at each stage, - Ensure any reasonably skilled user can follow and hit the same issue. ### Expected Behavior Hello guys, I would like to display custom error messages in Open WebUI chat when an exception is raised in my backend (API route). ### Actual Behavior I'm using FastAPI to send OpenAI requests between my LLM and Open WebUI, but when an exception is raised, the UI seems to be loading without displaying any error message. ### Steps to Reproduce I have OpenWebUI running in a Docker container. It's well connected with my backend because I can request my models. When I change the route, for example with this: @llm_router.post( "/chat/completions", tags=["chat"], summary="Query to the LLM model", status_code=status.HTTP_200_OK, responses={ status.HTTP_401_UNAUTHORIZED: {"description": "Authentication failed"}, status.HTTP_404_NOT_FOUND: {"description": "Invalid route"}, status.HTTP_408_REQUEST_TIMEOUT: {"description": "Timeout"}, status.HTTP_500_INTERNAL_SERVER_ERROR: {"description": "Unexpected error"}, }, ) async def openai_query_streaming(query: ChatCompletionRequest, authorization: str = Security(http_auth_method)) -> StreamingResponse: """ Query the AWS LLM, given a user prompt """ raise HTTPException(status_code=404, detail="Item not found") return Nothing display on the UI. ### Logs & Screenshots Python log : <img width="940" height="33" alt="Image" src="https://github.com/user-attachments/assets/da5a21c7-4836-4e75-9a7a-88fe88d0120f" /> Open webUI : <img width="800" height="224" alt="Image" src="https://github.com/user-attachments/assets/ceafafb3-f687-418e-95cd-7187cf413302" /> ### Additional Information Thank you for your help guys !

GiteaMirror commented

2026-05-05 20:45:40 -05:00

Owner

Originally created by @VRivi on GitHub (Oct 13, 2025).
Original GitHub issue: https://github.com/open-webui/open-webui/issues/18295

Check Existing Issues

I have searched for any existing and/or related issues.
I have searched for any existing and/or related discussions.
I am using the latest version of Open WebUI.

Installation Method

Docker

Open WebUI Version

v0.6.33

Ollama Version (if applicable)

No response

Operating System

windows 11

Browser (if applicable)

Confirmation

I have read and followed all instructions in README.md.
I am using the latest version of both Open WebUI and Ollama.
I have included the browser console logs.
I have included the Docker container logs.
I have provided every relevant configuration, setting, and environment variable used in my setup.
I have clearly listed every relevant configuration, custom setting, environment variable, and command-line option that influences my setup (such as Docker Compose overrides, .env values, browser settings, authentication configurations, etc).
I have documented step-by-step reproduction instructions that are precise, sequential, and leave nothing to interpretation. My steps:
Start with the initial platform/version/OS and dependencies used,
Specify exact install/launch/configure commands,
List URLs visited, user input (incl. example values/emails/passwords if needed),
Describe all options and toggles enabled or changed,
Include any files or environmental changes,
Identify the expected and actual result at each stage,
Ensure any reasonably skilled user can follow and hit the same issue.

Expected Behavior

Hello guys,

I would like to display custom error messages in Open WebUI chat when an exception is raised in my backend (API route).

Actual Behavior

I'm using FastAPI to send OpenAI requests between my LLM and Open WebUI, but when an exception is raised, the UI seems to be loading without displaying any error message.

Steps to Reproduce

I have OpenWebUI running in a Docker container.
It's well connected with my backend because I can request my models.

When I change the route, for example with this:

@llm_router.post(
"/chat/completions",
tags=["chat"],
summary="Query to the LLM model",
status_code=status.HTTP_200_OK,
responses={
status.HTTP_401_UNAUTHORIZED: {"description": "Authentication failed"},
status.HTTP_404_NOT_FOUND: {"description": "Invalid route"},
status.HTTP_408_REQUEST_TIMEOUT: {"description": "Timeout"},
status.HTTP_500_INTERNAL_SERVER_ERROR: {"description": "Unexpected error"},
},
)
async def openai_query_streaming(query: ChatCompletionRequest, authorization: str = Security(http_auth_method)) -> StreamingResponse:
"""
Query the AWS LLM, given a user prompt
"""
raise HTTPException(status_code=404, detail="Item not found")
return

Nothing display on the UI.

Logs & Screenshots

Python log :

Open webUI :

Additional Information

Thank you for your help guys !

GiteaMirror added the bug label 2026-05-05 20:45:40 -05:00

GiteaMirror closed this issue

2026-05-05 20:45:41 -05:00

[GH-ISSUE #18295] issue: Display custom error messages #57223