Pi Is the Last Harness

mark_l_watson

I agree that pi is very good, don’t agree that it is the last harness (I have written 4 harnesses myself this year, fantastic experience.) I mostly use local models. I use pi with the strongest models my 64g mac can handle, and for fast light work I use ‘pool’ with Laguna 2.1 XS 6 bit quant. I am happy :-)

dcastm

I went in trying to earn why Pi was such a good harness and did not learn anything. I’m really curious to learn why someone might consider it to be 10x better than Claude Code. > Pi is Lindy ↗. It’s been around for a year and has arguably the biggest developer community across all harnesses. It’s here to stay. BTW this isn’t what Lindy really means

baalimago

I'm sure there are many more harnesses like Pi. Clai[0] (which I've written) is one of them. We also have hax[1] and aichat [2]. I made some additional comparisons here[3]. At the end of the day, it's quite easy to write together a bespoke agentic harness. So I'm sure there are countless additional ones. You don't really need a lib/open source one at all. Just make it write itself. [0]: https://github.com/baalimago/clai [1]: https://github.com/OleksandrChekhovskyi/hax [2]: https://github.com/sigoden/aichat [3]: https://www.clai.chat/compare/

VMG

> Sure, there are certain features [....] but I don’t see how those couldn’t become part of Pi eventually, either natively or via plugins. No. I'm done with npm-style dependency sprawl and the supply chain nightmares. Done with plugins, extensions, marketplaces with "install at your own risk" disclaimers. Give me a opinionated monolith by somebody who has something at stake and doesn't externalize these costs, i.e. a corporation. Maybe once we live in a world with lean-verified wasm-sandboxed provable-secure software we can get back to installing software written by randos on the internet.

rcarmo

Tau is kind of taken as a name, BTW, by the Python harness from Huggingface. And I do agree Pi is great, but what makes it great is the back-end (pi-durable, pi-ai, etc.). I've been working on https://github.com/rcarmo/piclaw for most of the year, as well as https://github.com/rcarmo/gi and https://github.com/rcarmo/go-ai (as ports of pi and pi-ai/durable/etc., plus 3 or 4 pi-durable add-ons for Obsidian and other desktop apps) and the internals of pi are a grand thing indeed, because it was designed from the outset to be able to extend itself (which many people miss, because many people confuse the harness with the TUI).

tkdb

I don't love the attempt to clarify the term "harness" or the analogy. "Engine" works well as the model. The car is the harness. Pushing back further (etymologically): A horse is the model. The harness connects the horse to the coach/wagon, where the user sits. Multiple horses may be connected in parallel. Maybe oxen (different models) are connected for certain jobs, which require a harness appropriate for the workload. I agree that harness, like agent, is a hype word and is often part of word soup. It's been at least a year now (an eternity in the AI wars) where the frontier model releases are just one factor we are using and weighing against competitors, and things I would put under the "harness" category matter as much or more.

minraws

I don't think we've seen the last of anything in 2026/27. Lots of interesting projects are yet to start. I'd bet a good amount of money that some of the next Google/Microsoft-sized businesses will come from ideas in the AI harness/tooling space that no one has even noticed yet. No one is building them today, well, not exactly anyways. And no one will see it coming except that one person in some remote part of the world (I don't say the US because, post-LLMs, I hardly think there's anything unique to US tech anymore. The best part was the sheer technical talent in the US, but that's worth a lot less with modern models and systems). So no, I don't think we're anywhere near the end of innovation just yet. These will be some fun times, and I don't think the current way of building stuff will last too long. We'll definitely have better tools and ways of doing stuff, or so I hope. Keyboards have honestly lasted a lot longer than I would've expected, even though we've had STT tech for decades now. Even today, office memes aside, it's just easier to type things out instead of speaking. For most people, typing is faster or fast enough anyway. Except when I'm on my phone.

hypfer

Yeah? Well, you know, that's just like uh, your opinion, man. ___ What is the point of this blog post, declaring a problem solved with.. uh.. authority taking from.. uh.. uuuuuh. Anyway. Is pi good? I guess? The post does mention some of its qualities. Is it a sensible take to extrapolate this from that? I do not think so. Intellectually unstimulating.

athrowaway3z

What will break pi is that everybody is going to think themselves clever by calling their extension/frontend/fork 'tau'.

clutter55561

VSCode is the last editor, pi is the last harness, blah, blah blah

recursivedoubts

this article is hyperbolic, but pi is very nice, if a little raw for people used to more professional commercial harnesses i am vibing a harness extension on top of it for our students called catatui: https://msu.github.io/catatui/ that works w/our free-for-students-and-staff internal models & provides some student-oriented features, and it has worked very well

tamimio

Nah, pi to other harnesses is like archos to other distros: if you like spending your time tweaking and customizing the tool itself rather than doing the work, it will be the perfect match, that, plus it’s turning into a cult-like, exactly like archos. OMP is too convoluted with features that also resemble an old linux distro (can’t remember its name, i think ultimate) where the creator tries to shove all features in there, i remember that distro had all programs preinstalled plus all themes and everything, same with omp, plus omp terminal ui is ugly and behave badly if you resized the window, it feels like a hacky project. What’s really needed in any good harness: multiple providers, efficient on tokens, load skills, easy export of sessions, fast with clean ui, and open to customization if you needed with addons.

togilvie

My guess is we see a cambrian explosion in harnesses. Pi may well be the substrate for lots of them. But as coding agents get better, everyone can have a version that fits their needs like a glove.

plorkyeran

Invoking the Lindy Effect to proclaim that something that’s a year old will last forever is pretty funny. What the Lindy effect actually predicts is that something that’s a year old is pretty likely to only last one more year before being replaced.

klhs

>LLMs change everything around us, how we manipulate the world, and how we get the signals back. This is sounds a little too grandiose for me. Our physical lives at least seem quite unchanged. If you don't produce code or papers for a living you might even succeed in not thinking about LLMs at all. The "signals" we're getting have certainly multiplied and increased in amplitude, though. Regarding Pi: If hands-off code production is the future wouldn't a harness with subagents be the obvious choice? I personally enjoy minimalism in software, if only for aesthetic reasons, but even then: Can't you spin up your own bespoke version easily?

jauntywundrkind

Pi only relatively recently getting Pi Durable feels like the first time we could even start to entertain it as a long term option. Having memory, history feels like an incredibly low bar to cross. I don't see much argument here. This feels like a variety of "worse is better". > Separately, Pi is good enough that I don’t expect an alternative to be an order of magnitude better. I fundamentally cannot take this seriously as an argument. For a number of ways, one of them being the focus on how many zeroes can be added. These are such encompassing personal spaces for us, connect person, agent, code and tools so intimately. The idea that oh, this is good enough, feels preposterous. As so many others have said, we are just getting started. Pi itself is mostly blank slate, invites you to get started. To build something far better. I do think there's absolutely something to that idea, that the harness is sort of this start, a base, to build your agency atop. And I deeply think that your harness must be your to improve and iterate on, to adjust, that only those ecosystems that let people in will be of any long term interest and value, will be the site if innovation and building, the collectors of energy. The post shouts out DeepSeek Harness. I think OpenCode with its effect based core is also spitting some real fire too. As they ask on the Bluesky, "what else is like this?"

efxhoy

Is anthropic ok with using their models in non claude code harnesses?

stasomatic

I've seen many mentions of pi and omp, but I can't figure out what they bring to the table. Does one need to be in the 10x club? I don't have herds of agents, I have different "chats" for different project or search queries, on the desktop and CLI.

Garlef

I think working in a filesystem is a local maximum and making a harness that is agnostic of this might be a good idea. (True enough: It's a local maximum that is hard to overcome. But we already see glimpses here and there such as anthropics scion: Why would an agent even check out the codebase if it could delegate testing, etc to a bunch of runners?)