I had Fable 5 compile that Rust code to WebAssembly and build a browser-based playground for it, so you can try it out with Mermaid diagrams here: https://tools.simonwillison.net/grok-mermaid

A few more notes on my Grok code explorations on my blog: https://simonwillison.net/2026/Jul/15/grok-build/

These are all pointless forks, they will die in a year.

Bookmark this and check back.

The new Cursor model is good and Grok chat is decent as a 2nd or 3rd opinion.

I'm honestly not trying to spark a political conversation - but the target user base is far-right

I have friends who use it and rate it.

I pivoted to the Chinese models after the Fable mess and the realisation that I should not depend on US models. But others just pivoted away from Claude.

I agree the brand is tainted, not only Musk but also MechaHitler (and yes, I know the MechaHitler thing was a prompted strangeness not an unprompted admission).

Another tactical move is to just stop. You're allowed to exit the AI business. Nobody's forcing you to keep throwing money into the furnace. Just be a rocket company. All of the xAI founders left. Your product's brand name is mud. Just stop doing that and build spaceships.

It's definitely a smart move. Could easily leverage this to overtake competition.

I don't know anyone who would trust Grok Build anymore. I'd be wary of Cursor in the next few months too.

Yes, tactical is the right word because it might be a tactical win but it would be a strategic failure. Musks whole meme empire runs on vibes. The second there's a crack in the dam it all comes down. None of the valuations of anything he touches make sense and something like utterly failing to run with the AI big boys is enough to do that.

It definitely doesn't feel like opus. I constantly switch to opus to fix up or finish what grok generates, it feels like sonnet 3!

This has been my experience as well. In fact, Grok 4.5 is better at visual design than Fable from what I've seen.

And being (based on vibes) 2-3x faster? It's an easy sell to me.

Its amazing the speed of build with grok 4.5 its a taste of whats to come.

It’s a shame that their leader exfiltrated government data.

Now this is contrarian!

why pi over opencode? earnestly curious, trying to figure out what open solution people are consolidating on. (codex is also pseudo-open but contributions closed and nice)

Pi is good in concept, but why couldn’t they choose a compiled language instead of TypeScript?

I recommend using https://omnigent.ai over Grok Build or any other harness.

Cursor users are used to having multiple models from different providers

XAI wants people to use it's own model.

thats probably why they open sourced it and fix some reputation issue on top of it

You will be surprised how much code goes into creating harnesses.

a certificate that data was destroyed is absolutely worthless no matter who it comes from.

what kind of sorcery do they have to let them determine that no backups were taken before they arrived to "certify"?

How much can you really certify that data is destroyed?

Customer data could live on the computer Elon pretends to play Diablo 4 on for all we know.

How is this case any different from how cloud hosted AI agents work ? The agent needs all of those files to complete the task you give it & is not running locally.

So I don't think it can ever work without exhilarating the data - rather I am still surprised people don't understand the implications.

Grok Build seems faster to me than `omp` and Claude Code but I can't put my finger as to why. Anecdotally, after disabling code uploads the agent doesn't respond instantly anymore (it used to respond within milliseconds).

It looks like some of that high LoC is because they are vendoring some deps. There readme gives the reason to vendor some but not others as:

> These crates sit on the path that renders untrusted model output (diagram source → SVG). Vendoring gives a full audit surface, pins exact source, and avoids crates.io yanks. Local patches and upgrade checklists live in each crate’s Cargo.toml header comments — treat those as the source of truth when re-vendoring.

Which honestly feels like a misunderstanding of how cargo and yanks work. Each upstream package is locked to an exact version in your lockfile along with a cryptographic hash. The upstream can't change the source without you noticing. Unless you update your lockfile you will always pin to the exact version and source. When a package is yanked, it is still available for download if it is already in a lockfile. It just prevents new packages from resolving it. Crates.io will sometimes completely delete a package, but I've only seen that happen in cases of malware. It's fairly rare and seems out of line with the supply chain concerns here.

There are good arguments for relying on upstream package managers and there are good arguments for vendoring all packages. I've never seen a project mix before.

That is an insane amount of code for something like this!

Most likely, SpaceX killed the code uploading yesterday so they are definitely concerned about the backlash

> The researcher who exposed Grok Build uploading users' entire repositories to cloud storage says the transfers have stopped after a server-side change. Elon Musk has separately promised that all previously uploaded user data will be deleted.

https://www.theregister.com/ai-and-ml/2026/07/14/musk-promis...

And for generating an absolutely gargantuan amount of CSAM and non-consensual sexualized images, but yeah, exfiltrating data too.

How can an AI agent, that is usually running on some machine in the cloud, even run without actually pulling in the data into the cloud to work with it ?

Is there an idea some sort of fixed localy running code does filtering on the data before it is sent to cloud?

Still seems like it would not work very well if it actually did any safe filtering - as the model can't "think" without seeing the data and it won't see the data unless the data is loaded to cloud.

> exfiltrating user data (including env files, entire source code etc) which is what grok-build did here

I think env files are filtered out [1]. Anyway, the most suspicious code would be `upload_session_state` which is currently a stub function, though it is hard to say if it was only planned (badly) or has been removed as a damage control.

[1] https://github.com/xai-org/grok-build/blob/c1b5909ec707c069f...

The overly generous image/video generation was a product of their excess compute. No point in letting it sit idle while you build up your infrastructure. But you were getting far more than what you paid for. Now your quota more accurately reflects the cost to create it (even still its generous compared to api costs) but everyone has their expectations set based on the subsidized access. Perhaps giving away too much is counter productive because users will revolt once the quotas are changed to better reflect reality.

You pay Twitter money to generate thirty videos per day?

To some degree at least. This is a hulking monster of a codebase for what it does, it's definitely LLM-built and almost definitely requires an LLM to tackle at all.

yup you can compile, we tested and made sure all the features work before posting

TUI is a lot better for me, and I have preferred it since the 00s, before LLM products were even a thing.

For all the reasons there can be, one big reason is that it works on anything you can get a terminal on, you can use it over SSH, and the UI will be the same no matter where you use it.

I also like that they are very very fast and they don't have the incessant animations that are put into most desktop environments nowadays. If you're on MacOS, the terminal is the only only part of your computer without roadblocks everywhere.

It is a fashion thing. I am not saying that agentic TUIs are bad or anything but it is certain fashionable to use one in 2026.

And why are you assuming the industry converged to it when your following statement dismantles your assumption?

Spacex bought cursor, so it now has it’s agent ui which is just as good as codex + it’s multi-modal

Anthropic also has it’s own ui

Zai also launched theirs last month.

Everyone is converging back to UI.

The terminal was just a prototype, everyone knew that.

Why snowflakes? You can use /feedback in the app.

Please don't just post the most obvious snarky comment about a given topic. The guidelines make it clear we're trying for something better here. https://news.ycombinator.com/newsguidelines.html

Honestly a great question. I mean if it’s open source someone will check (I don’t use xAI but believe me I would be checking first if I did).

It's less of a bet against him. It's more of a bet for the future of humanity. And contrary to what Elon believes about himself, his work has been toxic for humanity for the last 5 years and is getting worse.

Did you take the Full Self Driving bets, too?