Mesa running on pycafe (pyodide 'deployment')

[maartenbreddels]

Hi all,

recently we pre-launched https://py.cafe - a platform to run, edit and share Python apps in the browser.
Also, as the creator of Solara, I was curious if Mesa worked on this platform, and it works nicely:

See: https://py.cafe/maartenbreddels/mesa-example-wealth

(Note: we have the option to store a preview image as well, which is ideal for docs or social sharing - the image URL is https://py.cafe/preview/maartenbreddels/mesa-example-wealth )

So you can create links with a preview image like this:

We use it for solara to communicate with users on how to do things, like share examples. We've also been working with other open source libraries to use it as a building block for documentation as the apps can be easily embedded in an iframe.

<iframe src="https://py.cafe/embed/maartenbreddels/mesa-example-wealth" width="100%" height="400px" border="0"></iframe>

It is also easy to 'extract' the code, to inject it in your docs, e.g.:

https://py.cafe/files/maartenbreddels/mesa-example-wealth/app.py

Let me know if the mesa developers find this useful, and if so, in what ways. We are happy to listen to ideas and feedback to improve py.cafe.

Regards,

Maarten Breddels

PS: it's not an open source product, but we will make sure the free usage is sufficient for open source usage.

[maartenbreddels]

FYI: see mckinsey/vizro#569 for how this project will use pycafe

[EwoutH]

Looks very interesting! We have been discussing some kind of equivalent to NetLogo Web for some time, this definitely looks like one of the more promising solutions. Native Solara and Plotly support is definitively a pre.

CC @rht @tpike3 @Corvince

[rht]

Looks promising! I will do more extensive testing later. Been swamped at work.

1. I noticed that Solara has to be installed from scratchevery time, if this could be cached (or could be faster via uv? not sure how Pyodide pip install works).
2. Due to the limited space available on my laptop screen, the user controls are displayed on top of the simulation plots.
3. Can it render folder hosted on GitHub, e.g. virus on network?
   

@Corvince made an example of sharing a model via Jupyter Lite / Pyodide: #1954, and comparing the UI, I think it is more hectic than py.cafe's. And I assume py.cafe is more lightweight as well? And indeed, with py.cafe, we can deploy something similar to NetLogo Web sooner.

[maartenbreddels]

Hi @rht

Thank you for trying this out, and your feedback.

1. It should not install every time, only when the requirements change. We use uv for resolving the dependencies (although this is an implementation detail). And, downloaded packages will be cached in the browser cache.
2. If you hit the maximize button on the top right next to the inline browser, the app shows without the editor (you should also see the browser URL change, this is also a URL you can share or use in a link)
3. It can kind of fetch a folder, but it's a bit manual, so I created a pycafe snippet that generates a pycafe snippet (yeah, pretty meta/inception): https://py.cafe/maartenbreddels/generate-url-for-mesa-virus-network (Note that we currently do not show directories in the file explorer, but we will work on that.)

[rht]

1. I see.
2. Yes it worked. Before you said this, I thought I'd have to modify Mesa's code to detect whether the env is py.cafe and choose the low-width layout. (note: I didn't notice that Solara now has solara.ColumnsResponsive, which didn't exist when we did the 2 layouts in the past. This will simplify the code.).
3. That's cool, will have to keep in mind of that capability. I saw that the snippet content is embedded in the URL.

I also measured the RAM usage via Chromium's memory browser. A tab consumes ~350 MB of RAM, about half of Jupyter Lite. Although when I opened the pycafe snippet generator, one of the tabs is at ~600 MB.

[maartenbreddels]

Actually, vaexio/vaex#2331 inspired me to look at vaex on wasm. I got it compiling, but it needs pyarrow (which is in the making).

Looking forward to your feedback and also your ideas on how you'd ideally want to use it.

[tpike3]

@maartenbreddels py.cafe is very cool! I am working on a similar project I think has overlap with yours, with the general goal of making tech and simulations more accessible. Would you have time for a videochat? Maybe the week of the 22nd?

[maartenbreddels]

Hi Tom,

absolutely, would love to chat. Please contact me at [email protected] to find a timeslot.

cheers,

Maarten

[EwoutH]

If you find a time, and you would allow me, I might be interested in joining, if I'm available.

[EwoutH]

I so wish I could just throw a few weeks of engineering time against this problem. Having interactive, no-code, user-facing examples would so helpful for students and modellers to get into the Mesa ecosystem. Like having all our examples runnable from an online interface without installing anything.

[maartenbreddels]

That's a shared dream then :)
We'd like to see projects do this, and we also want to do this for some of our own projects.

[EwoutH]

This would actually have been the perfect GSoC project. It's clearly compartmentalised. It's large, but not necessarily very difficult. It has very clear users value.

But no, everybody wants to do AI.