just-bash: Bash for Agents

https://github.com/vercel-labs/just-bash

31•tosh•2h ago

Comments

gaigalas•1h ago

https://github.com/vercel-labs/just-bash/blob/main/src/spec-...

That's a lot of incompatibilities.

LLMs like to use the shell because it's stable and virtually unchanged for decades.

It doesn't need to worry much about versions or whether something is supported or not, it can just assume it is.

Re-implementing bash is a herculean effort. I wish good luck.

esafak•1h ago

No, they use it because there's a lot of training material.

pro-tip: vercel's https://agent-browser.dev/ is a great CLI for agent-based browser automation.

gaigalas•1h ago

> No, they use it because there's a lot of training material.

Trained on an interpreter that is stable is virtually unchanged for decades. That's precisely my point.

It was never trained on an incompatible, partial implementation.

> agent-based browser automation

Clearly out of scope. You a bot?

athorax•1h ago

Why do you think there is a lot of training data? Could it be because it's stable and virtually unchanged for decades? Hmmm.

esafak•51m ago

Because bash is everywhere. Stability is a separate concern. And we know this because LLMs routinely generate deprecated code for libraries that change a lot.

gaigalas•46m ago

This project runs on all shells, totally portable:

https://github.com/alganet/coral

busybox, bash, zsh, dash, you name it. If smells bourne, it runs. Here's the list: https://github.com/alganet/coral/blob/main/test/matrix#L50 (more than 20 years of compatibility, runs even on bash 3)

It's a great litmus test, that many have passed. Let me know when just-bash is able to run it.

esafak•14m ago

I have no connection to coral or just-bash. Why don't you do it yourself and let us know, since you are familiar with it?

simonw•11m ago

Incompatibilities don't matter much provided your error messages are actionable - an LLM can hit a problem, read the error message and try again. They'll also remember that solution for the rest of that session.

jpitz•59m ago

Just curious: why wouldn't you attack this with a jail?

wild_egg•23m ago

Jails are alien magic and typescript is safe and familiar

IceWreck•57m ago

At this point why not make the agents use a restricted subset of python, typescript or lua or something.

Bash has been unchanged for decades but its not a very nice language.

I know pydantic has been experimenting with https://github.com/pydantic/monty (restricted python) and I think Cloudflare and co were experimenting with giving typescript to agents.

wild_egg•25m ago

Agents really do not care at all how "nice" a language is. You only need to be picky with language if a human is going to be working with the code. I get the impression that is not the use case here though

simonw•13m ago

Being unchanged for decades means that the training data should provide great results even for the smaller models.

sheept•5m ago

I feel like Deno would be perfect for this because it already has a permissions model enforced by the runtime

huntaub•57m ago

We just released a driver that allows users of just-bash to attach a full Archil file system, synced to S3. This would let you run just-bash in an enrivonment where you don't have a full VM and get high-performance access to data that's in your S3 bucket already to do like greps or edits.

Check it out here: https://www.npmjs.com/package/@archildata/just-bash

Lerc•53m ago

I have been playing around with something like this.

I'm not going for compatibility, but something that is a bit hackable. Deliberately not having /lib /share and /etc to avoid confusion that it might be posix

On neocoties for proof of static hosting

https://lerc.neocities.org

RobertLong•43m ago

This ends up reading files into node.js and then running a command like grep but implemented in JS. I love the concept but isn’t this incredibly slow compared to native cli tools? Building everything in JS on top of just readFile and writeFile interfaces seems pretty limited in what you can do for performance.

simonw•12m ago

Performance of the tools doesn't really matter when you have a full LLM inference loop in between each tool call.

_pdp_•28m ago

Interesting concept but I think the issue is to make the tools compatible with the official tools otherwise you will get odd behaviour. I think it is useful for very specific scenarios where you want to control the environment with a subset of tools only while benefiting from some form of scripts.

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just-bash: Bash for Agents

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