[GH-ISSUE #20823] issue: Documentation confusing: Events are supported in OpenAPI based tools or not? #122609

New Issue

GiteaMirror · 2026-05-21T01:30:23-05:00

GiteaMirror commented

2026-05-21 01:30:23 -05:00

Originally created by @reuschling on GitHub (Jan 20, 2026).
Original GitHub issue: https://github.com/open-webui/open-webui/issues/20823

Check Existing Issues

I have searched for any existing and/or related issues.
I have searched for any existing and/or related discussions.
I have also searched in the CLOSED issues AND CLOSED discussions and found no related items (your issue might already be addressed on the development branch!).
I am using the latest version of Open WebUI.

Installation Method

Docker

Open WebUI Version

v0.7.2

Ollama Version (if applicable)

0.12.6

Operating System

Linux

Browser (if applicable)

Firefox

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

In the documentation, there is the explanation for the use of events inside tools: https://docs.openwebui.com/features/plugin/development/events/. It is not clear (to me) if this is also possible with tools implemented with an OpenAPI service. I suggest that this should be possible, but I am not sure how - there is no clear documentation on this. Nevertheless, there are some hints in the documentation:

https://docs.openwebui.com/features/mcp says "Choose MCP (Streamable HTTP) if you need: ... Streamed tool events over HTTP with emerging ecosystem support." => Streamed tool events are supported with MCP.
The documentation says the recommended way to offer a tool from a MCP service to OpenWebUI is with mcpo. There is written "To use an SSE-compatible MCP server, simply specify the server type and endpoint" => thus, it should be clearly possible to offer MCP SSE functionality with mcpo

In the case mcpo can offer SSE support, and due to the fact that mcpo creates an OpenAPI compatible server, this means that there must be SSE support for OpenAPI services. 1. gives the hint that MCP supports tool events.

Thus, I implemented a REST service with a "Content-Type:text/event-stream" response. I asked ChatGpt due to the lack of further documentation on this point and it says that now I can return events inside the stream, with the format

event: type
data: {some json}

as specified in the OpenWebUI documentation here. I know of course that this can be a hallucination, and it didn't work either.

I am currently totally confused if events with OpenApi tools are possible or not, but it is clear to me that the documentation leads me to this assumption. So there is at least a lack in

the event documentation, which should make it clear that events are possible with native/python implemented tools only (if this is the case) OR
the OpenAPI tool server documentation, how to implement events with the according REST interface AND/OR
the MCP documentation, how to implement events (which then can be offered via mcpo over OpenAPI/REST

This pull request initiated from this discussion talks about the possibility to use SeverSentEvents (SSE) from a backend. This is not from the documentation, but it is a further hint that events over SSE could be sent possibly from a tool OpenApi server also.

(If there is at the end no support for events with remote tools, I will create an according feature request as follow-up to this documentation issue)

Actual Behavior

--

Steps to Reproduce

--

Logs & Screenshots

--

Additional Information

No response

Originally created by @reuschling on GitHub (Jan 20, 2026). Original GitHub issue: https://github.com/open-webui/open-webui/issues/20823 ### 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 have also searched in the CLOSED issues AND CLOSED discussions and found no related items (your issue might already be addressed on the development branch!). - [x] I am using the latest version of Open WebUI. ### Installation Method Docker ### Open WebUI Version v0.7.2 ### Ollama Version (if applicable) 0.12.6 ### Operating System Linux ### Browser (if applicable) Firefox ### 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 In the documentation, there is the explanation for the use of events inside tools: https://docs.openwebui.com/features/plugin/development/events/. It is not clear (to me) if this is also possible with tools implemented with an OpenAPI service. I suggest that this should be possible, but I am not sure how - there is no clear documentation on this. Nevertheless, there are some hints in the documentation: 1. https://docs.openwebui.com/features/mcp says "Choose MCP (Streamable HTTP) if you need: ... Streamed tool events over HTTP with emerging ecosystem support." => **Streamed tool events are supported with MCP**. 2. The documentation says the recommended way to offer a tool from a MCP service to OpenWebUI is with [mcpo](https://github.com/open-webui/mcpo). There is written "To use an SSE-compatible MCP server, simply specify the server type and endpoint" => thus, it should be clearly possible to **offer MCP SSE functionality with mcpo** In the case mcpo can offer SSE support, and due to the fact that mcpo creates an OpenAPI compatible server, this means that there must be SSE support for OpenAPI services. 1. gives the hint that MCP supports tool events. Thus, I implemented a REST service with a "Content-Type:text/event-stream" response. I asked ChatGpt due to the lack of further documentation on this point and it says that now I can return events inside the stream, with the format ``` event: type data: {some json} ``` as specified in the OpenWebUI documentation [here](https://docs.openwebui.com/features/plugin/development/events#-event-payload-structure). I know of course that this can be a hallucination, and it didn't work either. I am currently totally confused if events with OpenApi tools are possible or not, but it is clear to me that the documentation leads me to this assumption. So there is at least a lack in * the event documentation, which should make it clear that events are possible with native/python implemented tools only (if this is the case) OR * the OpenAPI tool server documentation, how to implement events with the according REST interface AND/OR * the MCP documentation, how to implement events (which then can be offered via mcpo over OpenAPI/REST [This pull request](https://github.com/open-webui/open-webui/pull/12559) initiated from [this discussion](https://github.com/open-webui/open-webui/discussions/8461#discussioncomment-12718279) talks about the possibility to use SeverSentEvents (SSE) from a backend. This is not from the documentation, but it is a further hint that events over SSE could be sent possibly from a tool OpenApi server also. (If there is at the end no support for events with remote tools, I will create an according feature request as follow-up to this documentation issue) ### Actual Behavior -- ### Steps to Reproduce -- ### Logs & Screenshots -- ### Additional Information _No response_

GiteaMirror added the bug label 2026-05-21 01:30:23 -05:00

GiteaMirror closed this issue

2026-05-21 01:30:24 -05:00

GiteaMirror commented

2026-05-21 01:30:26 -05:00

@owui-terminator[bot] commented on GitHub (Jan 20, 2026):

🔍 Similar Issues Found

I found some existing issues that might be related to this one. Please check if any of these are duplicates or contain helpful solutions:

#20544 issue: Document uploading - Docling API
by n4gY1 • Jan 10, 2026 • bug
#20762 issue: "Navigate to the Knowledge section" is confusing documentation
by robogeek • Jan 17, 2026 • bug
#20775 issue: calls to tools in gpt-oss
by chdid • Jan 18, 2026 • bug

💡 Tips:

If this is a duplicate, please consider closing this issue and adding any additional details to the existing one
If you found a solution in any of these issues, please share it here to help others

This comment was generated automatically by a bot. Please react with a 👍 if this comment was helpful, or a 👎 if it was not.

@owui-terminator[bot] commented on GitHub (Jan 20, 2026): 🔍 **Similar Issues Found** I found some existing issues that might be related to this one. Please check if any of these are duplicates or contain helpful solutions: 1. [#20544](https://github.com/open-webui/open-webui/issues/20544) **issue: Document uploading - Docling API** *by n4gY1 • Jan 10, 2026 • `bug`* 2. [#20762](https://github.com/open-webui/open-webui/issues/20762) **issue: "Navigate to the Knowledge section" is confusing documentation** *by robogeek • Jan 17, 2026 • `bug`* 3. [#20775](https://github.com/open-webui/open-webui/issues/20775) **issue: calls to tools in gpt-oss** *by chdid • Jan 18, 2026 • `bug`* --- 💡 **Tips:** - If this is a duplicate, please consider closing this issue and adding any additional details to the existing one - If you found a solution in any of these issues, please share it here to help others *This comment was generated automatically by a bot.* Please react with a 👍 if this comment was helpful, or a 👎 if it was not.

GiteaMirror commented

2026-05-21 01:30:26 -05:00

@Classic298 commented on GitHub (Jan 20, 2026):

Please open documentation questions in docs repo not here.

Then i can look into it

@Classic298 commented on GitHub (Jan 20, 2026): Please open documentation questions in docs repo not here. Then i can look into it

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Reference: github-starred/open-webui#122609