Pi's Minimalism Is Its Advantage
Pi, the coding harness from Earendil, deliberately keeps its system prompt and tool set minimal—under 1,000 tokens—to reduce context overhead and cost. Databricks' benchmark found that Pi, combined with Opus 4.8, achieved the highest pass rate at significantly lower cost per task than Claude Code or Codex. Shopify built an extension called Autoresearch on Pi, which sped up unit tests 300x and cut build times. Pi's extensibility lets users add only what they need, and its context discipline makes it ideal for local models.
In many cases, simple harnesses like Pi performed best on our workloads.
- paldepind2
Lots of praise for Pi in this thread, so I'll offer up a diverging opinion. Given all the hype, I was a bit underwhelmed by Pi. It definitely has some good ideas around customization, but it annoyed me in many little ways.
For a program that's minimal it sure takes a long time to start up, the standard C-p and C-n bindings don't work, it doesn't follow the XDG Base Directory Specification and just pollutes my $HOME directory.
I think there's still space for another harness that's 1/ open-source, 2/ written in a fast compiled language (Rust, Go, etc.) and scriptable in a simple (aka non-JS) scripting language (Lua, etc.), 3/ less opinionated and more sensible so things like XDG isn't a WONTFIX.
- pavo-etc
I've had a lot of success running Pi on my server in headless mode and wrapping it in an XMPP client. This means I can talk to it wherever I can access XMPP (everywhere). It also mean agents can talk to each other when they need to. They've got a shared wiki they interact with and github issues as their todo list.
I am running several named pi instances in parallel in their own user account on NixOS, so they can install whatever they want in ephemeral shells and I never need to worry about their env. The agents can spin up new enabled XMPP agents if I request it, though for now I've only needed a few since I'm not doing too much in parallel.
My Pi is very vanilla, only my own XMPP wrapper and pi-subagents extension for anonymous subagents.
Using it primarily with Deepseek v4 Flash for chipping away at coding tasks or server maintainence while I'm AFK or in transit.
NixOS is the key to all of this, since agents can interact see the whole server config, make changes and run compile-time checks before actually deploying. It also means that even if they do mess up I can always revert.
- mft_
I’m going to go against the grain and say that Pi is a little too minimal by default. The emacs comparison is interesting, but default Pi is like emacs that can load files but you’ve got to extend it manually to save or search within a file.
I’d argue that there’s a minimal set of functions that a coding harness needs to just enable a model to get stuff done, and they shouldn’t be an extra effort to set up.
(Oh-my-pi exists for those of a similar persuasion.)
- malisper
Having tried all the coding harnesses, I find that using Pi is exactly like using Emacs. For anything you want to build you can ask your agent and it will build it. There's tons of existing code to help you configure it. At the same time half the code is buggy, UI elements will try to overlap one another, and you'll periodically get crashes.
If you're willing to put in the work to master the learning curve and push through the issues, it can be a great tool: https://i.sstatic.net/7Cu9Z.jpg
- astrobiased
Pi does one thing that I love, developing a tool that has minimalism where it's easily configurable with good documentation. The leads to new use cases that the the author(s) would have never dreamed of. The organic growth process of the Pi ecosystem has been fascinating to observe. It's one of the reasons why Pi has become one of my favorite coding agents to this day, flexible beyond personal uses and extensible to larger environments.
IMO, I view it more than a coding agent, it's a coding agent platform with powerful extensibility.
- whazor
Both Codex and Claude have trained their models to their harnesses.
There are some experimentations by Igor Warzocha to extract Codex shapes and put it in Pi: https://github.com/IgorWarzocha/howaboua-pi-stuff/tree/main/...
I'm expecting every model will have a fine tuned Pi extension at some point.
- swingboy
Aside from the minimal system prompt, how does it handle context better than other agents? It still has to send the system prompt (which includes AGENTS.md and skill definitions) along with the full conversation every request, no?
- pornel
I'm enjoying the maximal version: https://omp.sh