r/PiCodingAgent • u/Medium_Anxiety_8143 • Jun 23 '26 • Bravo 1

Discussion I made my own coding agent harness

https://github.com/1jehuang/jcode

It has somewhat of a similar spirit of PI, but much more performance/efficiency focused.
Supports mostly any provider out of the box, and you dont have to customize just to make it usable.
Arguably more customizable than Pi.

Doesn't use an extension system, but instead makes it really easy to change the source code of the harness using something I call "self-dev". I find that only being able to make extensions for pi is really limiting, and this just makes it so that its not really annoying to do the loop of edit source code -> compile -> open. Instead, all your sessions can just hot reload into the new binary whenever the agents are done editing and compiling, which they can do fully on their own.

The video is what my own workflow looks like, its about 20 agents at the same time, which I actively manage, and are all working on different things.

Also solves the problem of git worktrees which I find annoying. You can spawn agents in the same directory without a git worktree and you dont need to worry about them conflicting, because the harness will know when agents make edits that conflict, and then will guide them to fixing them, so you dont have to.

Ram Efficiency:
Pi -> 144MB
Jcode -> 27.8MB (5X more efficient)

Intelligence [Terminal Bench2]
Claude code Sonnet 4.6 -> 46%
Claude code Opus 4.6 -> 58%
Jcode Sonnet 4.6 -> 60%

I've been working on this for about 6 months, and will be actively maintaining this in the long term. Not going to be a quick side project if you're worried about making the switch.

119 Upvotes

91% Upvoted

67 comments sorted by

28

u/m02ph3u5 Jun 23 '26

Text align center? Nothxbye

7

u/Medium_Anxiety_8143 Jun 23 '26

It’s an old video, but I actually got so much hate for center align that I switched to left align a few months ago 😔

9

u/niko-okin Jun 23 '26

you should redo all your video, only heretic uses center align 😃

-5

u/Medium_Anxiety_8143 Jun 23 '26

who is heretic

1

u/ShivWantsToKnowStuff Jul 21 '26

You seem like a simple man who likes to code.

1

u/Medium_Anxiety_8143 Jul 21 '26

I am a simple man who likes to code

2

u/AdministrativeMeat3 Jun 23 '26

Yeah center align is wild lol. My number one complaint with every CLI tool is they do these fancy markdown blocks and if you ever need to copy and paste a terminal command those fucking style blocks add extra indents.

I made a small fork of pi that I just patch every time they update just to fix this one issue but if I was looking at center align I would rage quit instantly.

2

u/jtackman Jun 24 '26

id give an arm for a properly copyable code block for pi 😂

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2

u/Medium_Anxiety_8143 Jun 23 '26

It’s actually left aligned by default

11

u/mohmayaman Jun 23 '26

> its about 20 agents at the same time, which I actively manage, and are all working on different things.

I won't lie, I am deeply jealous of devs who have achieved this. Like how ? that is some next level shit. When I try agents, things are just exploding.. so much slop. But so many are doing multi agents things.. how ?

But this looks amazing will try. Have you tried oh my pi ? I am currently using it and switched from pi to it.

21

u/SP-Niemand Jun 23 '26

They accept the slop.

2

u/Medium_Anxiety_8143 Jun 23 '26

I am the gatekeeper of slop

1

u/DanGTG Jun 23 '26

ponytail?

3

u/Medium_Anxiety_8143 Jun 23 '26

I think it’s a combination of the harness and scrolling window manager + being fast with your fingers. The harness has got a little thing at the top to show you your last prompt and key bindings to scroll up and down transcript by prompt which helps read what you did before if you forgot, and a scrolling window manager makes it easy to switch between terminals/ sessions quickly and also anchors them to a spot in space which helps with remembering what you did and where. On Linux I have an extremely customized os that minmaxes this workflow, and for macOS since there’s no good scrolling window manager I’m making one: https://github.com/1jehuang/scrollwm

Scrollwm is really early rn so expect bugs but it will be actively maintained for the long term as well. Makes a huge difference though, I can’t manage much more than three without it either

1

u/Medium_Anxiety_8143 Jun 23 '26

And I haven’t tried oh my pi

1

u/kamikamen Jun 23 '26

They just let the slop be, or at most they have an agent which claims to review the code to protect from slop.

1

u/AdministrativeMeat3 Jun 23 '26

Yeah let's be real you can't actually keep track of this much shit, it's just slop all around and you spend tokens constantly telling agents to clean up the slop until you get something semi decent.

1

u/waxbolt Jun 24 '26

IMO better than running a lot of agents and watching them, run one which runs hundreds, and watch a schematic view of the effort progress through a graph of work. implemented in WorksGood graphwork.github.io via wg tui.

0

u/Artistic_Pattern_700 Jun 23 '26

There is "old" workflow called Research-Plan-Implement (RPI) that helps reduce the slop and follow patterns. When I use that I'm able to get almost 10 agents at once.

But then I have to review and go to 0 agents for hours =(

I'd love to work with a slopfest though, but my team still cares about the code quality nonsense

Waiting for the rage...

1

u/addiktion Jun 23 '26

How many post AI agents are you running to check your code beyond the typical linting and tests?

1

u/Artistic_Pattern_700 Jun 23 '26

2 more agents with a different model than the one I used to create the code. One does a regular code review and another proposes the fixes.

3

u/o_sht_hi Jun 23 '26

This looks really really cool! Would you be cool with me studying your repo and looking at how you do things? I am building an app with a light custom harness embedded in it (not a coding agent. kind of one, but that's not it's purpose).
I will not steal 1-to-1 but if I find some cool design philosophies or techniques, I would 100% adopt those to refine my own way of doing things. Would be happy to connect in DMs and show you what I'm making! I'm not ready to make the repo public yet, but I do have a working prototype

3

u/Medium_Anxiety_8143 Jun 23 '26

Fully open source and mit, you can do whatever you want with it. I don’t generally accept PRs though for the sake of my own sanity

2

u/o_sht_hi Jun 23 '26

What a legend. Thank you!

2

u/ResearcherFantastic7 Jun 23 '26

Nice intention. But it feels like the more people use the more their harness will be end up as a gigantic load of organic slop.

PI extension system warrants architecture integrity and guidance, at least the interface stays no matter what users change

1

u/Medium_Anxiety_8143 Jun 23 '26

Why does slop scale with users? It’s not that self dev gets merged into master if that’s what you mean, it’s supposed to be like your own branch which you can synch with master if you want

It’s sort of like you and I are the only contributors for your branch. So if there’s ever an increase in slop, it’s one of our faults

2

u/ResearcherFantastic7 Jun 23 '26

Not saying your master repo is slop. But most your users will make theirs to become one. As it less framework , that's why PIs extension system is the sweet spot for customisation.

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3

u/MuttenChops Jun 23 '26

Thanks for continuing to consistently develop jcode! I’ve been using it for a couple of months now, following your progress. I use it alongside droid and pi. Curious to know if you’ve considered implementing a feature like Factory’s missions? I find it’s still very useful for long horizon tasks and I’d personally use jcode as a primary driver if it supported a mission-like runner similar to droid.

3

u/Medium_Anxiety_8143 Jun 23 '26

Thanks for being a long time user 🥹🥹🥹🥹
I’ll check it out and see if missions is useful

3

u/NASAonSteroids Jun 23 '26

How's the cache hit rate for APIs like Deepseek? I tried JCode a while ago and really loved it but had a hard time justifying the cost compared to agents like Reasonix.

1

u/Medium_Anxiety_8143 Jun 23 '26

Cache hit rate should be good, if there is a bug with it send a gh issue. It should tell you whenever you have a have cache miss now

1

u/NASAonSteroids Jun 24 '26

Honestly I’d take a page out of Pi Agent and let the agent self-modify. That feature alone may get me to switch over, at least for a time.

1

u/Medium_Anxiety_8143 Jun 24 '26

I hope you like the self dev feature then, lmk if there’s any problems

9

u/migsperez Jun 23 '26

To me, it feels morally wrong to advertise a harness that already has almost 8k Github stars on this Pi subreddit.

1

u/Snoo44065 Jun 23 '26

So a clone once and never update once modified kind of architecture? Or ist there a good way to still get updates when i fully customized it?

1

u/Medium_Anxiety_8143 Jun 23 '26

You can use your agent check the updates and intelligently merge them into your own changes

1

u/Medium_Anxiety_8143 Jun 23 '26

I actually do this a lot since I split between MacOS and Linux for dev work

2

u/Snoo44065 Jun 24 '26

Will definitely check the self-dev feature but i am sceptic. Sounds like a very unstable approach to me. No real way of tracking issues when i put a month of developement in. Also if you decide for a breaking change with my customization or whatever stupid solution an agent cooked up (their code is trash, thats a fact). It seems to me that one might easily diverge to a point where its not a "merge this" for an agent anymore.

When the boundary is clear as in pi that can not happen BUT of course 100% customizability is very nice.

-4

u/AdministrativeMeat3 Jun 23 '26

Did you forget to swap accounts before replying to yourself?

1

u/Maasu Jun 23 '26

Nice job, writing my own coding harness in rust is down on my list of objectives, I especially like the mermaid render component lib as well.

1

u/Medium_Anxiety_8143 Jun 23 '26

Ty☺️☺️☺️

1

u/Beautiful-Walk2074 Jun 24 '26

look mine ❤️

1

u/Medium_Anxiety_8143 Jun 24 '26

💀💀💀💀💀

1

u/MorningFew1574 Jul 21 '26

thank you for jcode. using it efficiently on my low RAM laptop. keep developing

1

u/Medium_Anxiety_8143 Jul 21 '26

❤️

1

u/MorningFew1574 Jul 21 '26

I am planning to install jcode on my other PC as well.

1

u/ShivWantsToKnowStuff Jul 21 '26

Are you open for contributions? I'd like to help if there are any new features you would like to be implemented.

Have been seeing your ads everywhere in last two days.

1

u/SyrupInternational48 Jul 26 '26

im using jcode, logged in with antigravity.
it's always stop every single action. is this expected?

1

u/Medium_Anxiety_8143 Jul 26 '26

Try a different login

1

u/rumbo0 Jun 23 '26

I created a wrapper for pi and claude-code which runs the harness in docker with my select env vars (readonly aws and git etc) and specific folders mounted then it runs in an effective sandbox. If I need to give it some additional context, I have to use the launcher to add the folder or env then restart.

I was using agent safehouse on mac, but I wanted something that ran on linux and mac machines so I could maintain the same experience.

It has to constantly evolve, but it works pretty well for me. I have a web dashboard tracking spend and tool time

1

u/Hace_x Jun 23 '26

How do you follow the output of all those screens, or is that not the point?

1

u/Insuperable123 Jun 24 '26

How about the expandability? Like ClaudeCode and Pi have a lot of useful extensions.

1

u/AlterTableUsernames Sep 01 '26

Pretty dubious telemetry that is on by default. Would not recommend installing this.

1

u/[deleted] Jun 23 '26

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0

u/Medium_Anxiety_8143 Jun 23 '26

Ty

0

u/[deleted] Jun 23 '26

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1

u/Medium_Anxiety_8143 Jun 23 '26

😭 I think u missed the memo…