alt Hacker NewsPi – A minimal terminal coding harness
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My current fave harness. I've been using it to great effect, since it is self-extensible, and added support for it to https://github.com/rcarmo/vibes because it is so much faster than ACP.
I haven’t met a single person who has tried pi for a few days and not made it their daily driver. Once you taste the freedom of being able to set up your tool exactly how you like, there’s really no going back.
and you can build cool stuff on top of it too!
Preconfigured PI: https://github.com/can1357/oh-my-pi
Hugging Face now provides instructions for using local models in Pi:
Pi has made all the right design choices. Shout out to Mario (and Armin the OG stan) — great taste shows itself.
Is that an official term "coding harness"
Wondering if you wanted a similar interface (though a GUI not just CLI) where it's not for coding what would you call that?
Same idea cycle through models, ask question, drag-drop images, etc...
I've been using pi via the pi-coding-agent Emacs package, which uses its RPC mode to populate a pair of Markdown buffers (one for input, one for chat), which I find much nicer than the awful TUIs used by harnesses like gemini-cli (Emacs works perfectly well as a TUI too!).
The extensibility is really nice. It was easy to get it using my preferred issue tracker; and I've recently overridden the built-in `read` and `write` commands to use Emacs buffers instead. I'd like to override `edit` next, but haven't figured out an approach that would play to the strengths of LLMs (i.e. not matching exact text) and Emacs (maybe using tree-sitter queries for matches?). I also gave it a general-purpose `emacs_eval`, which it has used to browse documentation with EWW.
Note there is a fork oh-my-pi: https://github.com/can1357/oh-my-pi of https://blog.can.ac/2026/02/12/the-harness-problem/ fame. I use it as a daily driver but I also love pi.
Coming from OpenClaw, it's pretty amazing how fast pi is, particularly paired with Qwen3 that dropped today. It's a magical time.
Pi was probably the best ad for Claude Code I ever saw.
After my max sub expired I decided to try Kimi on a more open harness, and it ended up being one of the worst (and eye opening experiences) I had with the agentic world so far.
It was completely alienating and so much 'not for me', that afterwards I went back and immediately renewed my claude sub.
I've been using Pi day to day recently for simple, smaller tasks. It's a great harness for use with smaller parameter size models given the system prompt is quite a bit shorter vs Claude or Codex (and it uses a nice small set of tools by default).
Pi ships with powerful defaults but skips features like sub-agents and plan mode
Does anyone have an idea as to why this would be a feature? don't you want to have a discussion with your agent to iron out the details before moving onto the implementation (build) phase?
In any case, looks cool :)
EDIT 1: Formatting EDIT 2: Thanks everyone for your input. I was not aware of the extensibility model that pi had in mind or that you can also iterate your plan on a PLAN.md file. Very interesting approach. I'll have a look and give it a go.
Has anyone used an open coding agent in headless mode? I have a system cobbled together with exceptions going to a centralized system where I can then have each one pulled out and `claude -p`'d but I'd rather just integrate an open coding agent into the loop because it's less janky and then I'll have it try to fix the problem and propose a PR for me to review. If anyone else has used pi.dev or opencode or aider in this mode (completely non-interactive until the PR) I'd be curious to hear.
EDIT: Thank you to both responders. I'll just try the two options out then.
Anyone tried pi with 5.3-codex vs codex cli?
there is also pz a drop-in replacement for pi rewritten in Zig. 1.7MB static binary, 3ms startup, 1.4MB RAM idle. Find more at:
https://github.com/elyase/awesome-personal-ai-assistants?tab...
What are people using to cost efficiently use this? I was using a Google Ultra sub which gave enough but that’s gone now.
ChatGPT $20/month is alright but I got locked out for a day after a couple hours. Considering the GitHub pro plus plan.
I’m working with a friend to build an ui around Pi to make it more user friendly for people who prefer to work with a gui (ala conductor). You can check out the repo: https://github.com/philipp-spiess/modern
ive been using pi for about a week as daily driver and so far im happy with it. I really like the modular concept and also that its rather minimal
Interesting approach to planning via extensions. I took a similar direction with enforcement. A governance loop that hooks into the agent's tool calls and blocks execution until protocol is followed. Every 10 actions (configurable), the agent re-centers. No permission popups, but the agent literally can't skip steps.
Open source: https://github.com/isagawa-co/isagawa-kernel
The way you’re able to extend the harness through extension/hook architecture is really cool.
Eg some form of comprehensive planning/spec workflow is best modeled as an extension vs natively built in. And the extension still ends up feeling “native” in use
too bad I cannot star this.. https://github.com/badlogic/pi-mono/tree/main/packages/codin...
What's a coding harness? Claude Code is a "harness" and not a TUI?
I’ve been testing it for a few days on pretty much clean install (no customizations/extensions) and it’s ok. Not sure if I like it yet.
Excited to give this a try, looks really well done.
Anyone managed to run pi in a completely sandboxed environment? It can only access the cwd and subdirectories
But I can't use my Codex plan with it, right? I have to use an API key?
Naming skills though...
Another batteries included pi setup. Built a lightweight mobile webui to run it on termux and code on my phone.
Pi treats you like an adult and shows whatever the fuck LLM is doing rather than actively hiding shit from the user. And just for that, once you tasted the freedom and transparency, there’s no way to go back to CC.
I mean using the captive agents is much cheaper than supplying your api key to a 3rd party agent.
Wtf is that example gif?
The prompt shown is
"Who's your daddy and what does he do?"
Is this a joke or tech? Is the author a dev or a clown?
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The backing to OpenClaw/MoltBot whatever they're calling themselves. Why is it insecure, well, Pi tells you >No permission popups.
Anyway, even if you give your agent permission, there's no secure way to know whether what they're asking to is what they'll actually do, etc.
To me, the most interesting thing about Pi and the "claw" phenomenon is what it means for open source. It's becoming passé to ask for feature requests and even to submit PRs to open source repos. Instead of extensions you install, you download a skill file that tells a coding agent how to add a feature. The software stops being an artifact and starts being a living tool that isn't the same as anyone else's copy. I'm curious to see what tooling will emerge for collaborating with this new paradigm.