FUSE is All You Need – Giving agents access to anything via filesystems

https://jakobemmerling.de/posts/fuse-is-all-you-need/

35•jakobem•2h ago

Comments

heavyset_go•1h ago

IMO, for real file systems, just give a view via cgroups/namespaces.

Implementing a database abstraction as a file system for an LLM feels like an extra layer of indirection for indirection's sake: just have the LLM write some views/queries/stored procs and give it sane access permissions.

LLMs are smart enough to use databases, email, etc without needing a FUSE layer to do so, and permissions/views/etc will keep it from doing or seeing stuff it shouldn't. You'll be keeping access and permissions where they belong, and not in a FUSE layer, and you won't have to maintain a weird abstraction that's annoying/hampered with licensing issues if you want to deploy it cross platform.

Also, your simplified FUSE abstraction will not map accurately to the state of the world unless you're really comprehensive with your implementation, and at that point, you might as well be interacting directly in order to handle that state accurately.

jakobem•1h ago

Agree that to far fetched mappings to files don’t really make sense. The email example is more illustrative then real world inspired, thought it might be good to show how flexible the approach is.

I think there is a gap between “real file systems” and “non file things in a database” where mapping your application representation of things to a filesystem is useful. Basically all those platforms that let users upload files for different purposes and work with them (ex Google Drive, notion, etc). In those cases representing files to an agent via a filesystem is the more intuitive and powerful interface compared to some home grown tools that the model never saw during training.

ximeng•37m ago

LLMs can handle Google drive perfectly well with a service account, including the Google drive specific quirks through the API. It could be helpful to expose via a file system rather than a custom API if you wanted a different interface than Google already provides, but this wouldn’t be driven by the limitations of the LLM.

jakobem•27m ago

In terms of ergonomics, I’d say a filesystem is more intuitive for an agent than the Google Drive API even if it can handle both. Hard to argue without building an eval set and evaluating both, though.

outofpaper•11m ago

The less juggling of concepts thr more effective any problem solver cam be.

everlier•1h ago

I've implemented agentic framework exactly like this for my current employer.

It opens up absolutely bonkers capabilities.

moonlet•58m ago

I am so sick of the ‘sandboxed’ AI-infra meme. A container is not a sandbox. A chroot is not a sandbox. A VM is also not a sandbox. A filesystem is also also not a sandbox. You can sandbox an application, you can run an application in a secure context, but this is not a secure context the author is describing, firstly, and secondly they haven’t described any techniques for sandboxing unless that part of the page didn’t load for me somehow.

jakobem•56m ago

Didn’t mean to say this is a sandbox, it certainly isn’t, this is just an illustration on how to bridge the gap and make things available in a file system from the source of truth of your application.

There is tons of more complexity to sandboxing, I agree!

tptacek•44m ago

Wait, can you provide the positive definition for "sandbox" you're relying on here?

lagniappe•31m ago

Please brother may i have some pledge unveil

Eikon•46m ago

For ZeroFS [0], I went an alternate route with NFS/9P. I am surprised that it’s not more common as this approach has various advantages [1] while being much more workable than fuse.

[0] https://github.com/Barre/ZeroFS

[1] https://github.com/Barre/ZeroFS?tab=readme-ov-file#why-nfs-a...

jakobem•41m ago

Interesting! The network first point makes a lot of sense, especially bc you will most likely not access your actual datastore within the process running in the sandbox and instead just call some server that handles db access, access control etc.

fleshmonad•32m ago

Welcome back Plan9

mickael-kerjean•3m ago

> My prediction is that one of the many sandbox providers will come up with a nice API on top of this that lets you do something like ... No worrying about FUSE, the sandbox, where things are executed, etc. This will be a huge differentiator and make virtual filesystems easily accessible to everyone.

I've done exactly that with the Filestash [1] virtual filesystem plugin [2] that can connect to any possible storage be it sftp, s3, gdrive, dropbox, ftp, a open directory, mysql, postgres and literally any storage the possibly exist. It lets you make chroot and restrict user access on top of it [3]

ref:

[1]: https://github.com/mickael-kerjean/filestash

[2]: https://www.filestash.app/docs/guide/virtual-filesystem.html

[3]: https://imgur.com/Ewk3nAg

The whole thing is available as a MCP and been published to the openai marketplace since around Christmas but somehow I'm still pending for review.

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