David R. MacIver

Want to work on property-based testing with me? We're hiring in London to work on Hegel (https://hegel.dev)

https://antithesis.com/company/careers/?ashby_jid=e9fd4e23-6cd4-4556-bec8-2bb07756cc1b

Based on what I've seen from them I would bet that they're mostly pretty close to good implementations (except for the Agda one. I don't think the Agda one works at all. I gave the task to Claude because I like making robots suffer and wanted to see what would happen) but I'd expect they contain at least one absolute howler.

I've been working on a claude-code plugin for developing new Hegel client libraries and thought it would be interesting to share some of its output, so now we have an experimental repo for stuff that you probably shouldn't use... ha ha unless? No, you probably shouldn't use it.
https://github.com/hegeldev/experimental

But we do now have Hegel for Agda, Java, Perl, and Racket in there.

@csepp @rixx (It's not clear to me that this is what happens though. Also a lot of the value-add can be done less well with open weight models today, and I'd bet on them catching up enough to be good at the drudge work that is where the biggest value add is)

@csepp @rixx I'll probably use it less for personal projects, but I think you could hike up the price by 10x and I'd still think it was worth it at work.

Typescript is next on the official schedule but my guess is we'll probably release a sneaky C++ or OCaml version first.

Oh BTW we said we'd release Hegel for Go in a week or two, and two weeks later here you are, hegel-go: https://github.com/hegeldev/hegel-go / https://pkg.go.dev/hegel.dev/go/hegel

(We actually released it on Friday but delayed telling anyone)

@griotspeak@soc.mod-12.com Yeah, hand translating also perfectly valid! Give it a go. It won't be entirely straightforward, but it should be a lot easier than a full Hypothesis port.

@griotspeak@soc.mod-12.com Today: It'll be a little bit rough, but you could try just porting the rust library. It's not a huge amount of code. Bet Claude or another coding agent could do most of the work. We're going to get the protocol properly documented and to put a bunch more work into making it easy for people to spin up new libraries, but aren't quite there yet.

@tintvrtkovic@mastodon.social What do you want from me! I wrote https://github.com/DRMacIver/shrinkray It's a totally different testing tool that results from me obsessing about test-case reduction! I have breadth and versatility!

Lots of plans for the future of these libraries. This is very much just the start. But I'm pretty pleased with where we are as a start.

More soberly: In a week or two, Go. Then some other languages. And of course a whole bunch of engineering and UX work as people use this thing and inevitably find that it is perfect and wonderful and has no flaws and we just have to spend all our time fielding praise for how great we are. (And maybe fix a few bugs)

So like I mentioned I joined Antithesis a little while back. When I did, I pitched them on a crazy idea. Antithesis... Hypothesis... Hegel!

A remarkably short number of months later, Hegel. Hegel is a property-based testing protocol and family of client libraries which makes it easy to do Hypothesis-grade PBT everywhere.

Today: Rust. Tomorrow: The world! (Muahaha)

https://antithesis.com/blog/2026/hegel/