Serving multiple marimo apps on the same fastapi app

Question

I am trying to serve marimo apps on a company server (python, not webassembly).
I have fastapi working fine, but I am running up against a problem with imports.

Originally I thought the sandbox imports would work, but it looks like this is not the case (I found a message on this discord).

That leaves a few options to solve the import problem:

use mo.install() to somehow pull in the sandbox imports? But if all the apps are in the same marimo process does this create conflicting imports? Also how would I read in the imports?
use marimo run --sandbox and have each app have its own process and port that i have to forward to
use a global uv environment for all apps and keep it synced across apps somehow. This will eventually lead to conflicts.

Obviously my preference would be something where i can just have one marimo fastapi app,
but I am not sure what the best way to achieve this is, while keeping apps sandboxed.
Generally each app will have many imports.

Thanks for any advice!

Myles Scolnick · Answer

We don’t have a great solution now out of the box.

Installing before each app is probably the simplest but you do run into a potential conflict issue polluting the global environment. Do you envision you’d have conflicts? I guess pinning each dep in each app probably does create conflicts?

This has been requested a few times. We can try to prioritize this sooner.

btnaughton · Answer

thanks! i am now looking at spawning a marimo run --sandbox when the url is hit, and then using fastapi to proxy that port? i can't tell how janky that will be but i think it should work?i love sandbox and i think conflicts are unfortunately inevitable with bioinformatics tools!

Myles Scolnick · Answer

I think the proxying could work too. You could open source that and see if others want to contribute (and maybe we can contribute too)

btnaughton · Answer

I had a pretty decent stab at this but I could not get the websocket stuff to work.There is a nice library that in theory should be exactly what is neededhttps://github.com/WSH032/fastapi-proxy-lib?tab=readme-ov-filebut even my minimal code fails, so i gave up for now!import uvicorn
from fastapi_proxy_lib.fastapi.app import reverse_http_app
app = reverse_http_app(base_url="http://localhost:8001/")
if __name__ == "__main__": uvicorn.run(app, host="127.0.0.1", port=8000)

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Serving multiple marimo apps on the same fastapi app