Guidance on Tools/MCP when using both the API and the web interface

[jfahrenkrug]

Hello,

I'm new to Open WebUI. I have a specific question: For a client I'd like to turn an internal LangChain-based AI-prototype into a more sophisticated system. The current prototype uses function-calling to retrieve specific data and so forth. We have close to 10 tools/functions that the LLM can invoke. The prototype also includes a FastAPI-based REST API that exposes a chat-endpoint that uses the same LangChain logic, including function-calling etc. You get the same results from the API as you would from the web interface, because both have access to the same tools.

To make for a much nicer user experience, I'd like to transition to Open WebUI. I have the following requirements:

• Integrate custom tools that are "always on" for all users
• Ensure that those same tools are active when requests come in through the API

My question is: How to best accomplish this with Open WebUI? Should I use Tools (https://docs.openwebui.com/features/plugin/tools/) or MCP(O)?
I was leaning towards MCP(O), but I absolutely need to make sure that (1) these tools are always active for all users - requiring each user to manually activate these tools for each chat would be a deal-breaker, and that (2) those tools are also active when requests come in through the API. Is that doable? What's the best approach?

Thank you very much!

• Johannes

[bgoewert]

MCP (Streamable HTTP) is supported under /admin/settings/tools
https://docs.openwebui.com/openapi-servers/mcp