What Is a Harness? (earendil.com)

213 pointsby tosh7 hours ago111 comments

theturtletalks 7 hours ago

Harnesses are the next frontier. If LLMs are electricity, harnesses are the “electronics.” Right now, it’s like an AC vs DC between Claude and ChatGPT, but once that settles, the harnesses will be the actual value providers.

And Pi is the best harness because of the amazing extension system. You can build extensions that turn Pi into a stock trader, software factory, anything. I tried switching to another harness but none have extension functionality as good as Pi.

Even if there is a new harness or agent project, I tell Pi to dig into the codebase and then make me an extension that brings that functionality into Pi. I did it with Prime Intellect’s and Deepseek’s harnesses and those are built on Pi.

oceansky 7 hours ago

I want to move from Claude Desktop to Pi, but I found it a little unfriendly. Any tips to set it up?

zukzuk 7 hours ago

I haven’t tried it myself yet but I’m under the impression that Hermes Agent might be what you’re looking for?

cyanydeez 7 hours ago

what have you built other than a harness?

irishcoffee 7 hours ago

How does Pi compare to vscode? Admittedly that is the only “agent/harness” I’ve ever used.

GodelNumbering 7 hours ago

This is a plug, but relevant. I recently added a 'build native tools on the fly' functionality to Dirac (https://github.com/dirac-run/dirac) that works like:

1. You can use the '/new-tool' and tell what kind of tool you want (including whether it should be task-scoped, workspace-scoped, or global), the model builds it, the harness runs validation and other tests until the tool is ready

2. The model decides that in such and such task, it would be helpful to have a tool like this, it can build a task-scoped tool.

In either scenario, the tool catalog is rebuilt, and the new tool is instantly available in the next turn.

timbowhite 7 hours ago

Pi's most popular extensions, by download count:

https://pi.dev/packages?type=extension

dominotw 7 hours ago

i think its the opposite. claude code apparently removed hundreds of lines of system prompt because its not relavent anymore with newer models.

also i think its hard to build general harnesses if they were trained on specific harness architecture.

mpawelski 7 hours ago

> Harnesses are the next frontier. If LLMs are electricity, harnesses are the “electronics.”

I really though this comment was a satire ...

sejje 7 hours ago

What did you bring over from prime-agent? (I use prime-agent as my daily since it launched)

I primarily like how it manages sessions, and how agents can easily reference other sessions.

jascha_eng 7 hours ago

The ai hype word for 2026 after agent in 2025 for any LLM powered application.

Well kind of, I wouldn't be surprised to see that some things marketed as agents are actually good old deterministic software.

childofhedgehog 7 hours ago

Clear, relevant, and easy to understand. Thank you for writing this up, I’ll be sharing this link with all my non-tech friends!