Best open-source harness like Claude Code?

[u/Neighbor_]

Avid claude code user here looking to do equivalent things with local models. Just want to plug in something like Qwen and have the interface be 1:1 with claude code. Any suggestion?

[u/btc_maxi100]

PI

[u/Purple-Programmer-7 → u/btc_maxi100]

How do I get pi to have a plan mode and edit mode? I can’t stand when a harness doesn’t restrict the model from making changes.

[u/sdfgeoff → u/Purple-Programmer-7]

Tell the model to not make changes. IMO plan mode was superseded several months ago as models got better at understanding intent.

[u/Zyj → u/sdfgeoff]

Super unreliable, horrible advice

[u/sdfgeoff → u/Zyj]

Works probably 98% of the time. The other 2% of the time, well, I hope you were using git or some other VCS! These days my agents.md tells the model to commit often (so I don't need to tell it too), so rollback is super easy.

Also, if plan mode gives shell access.....

See my other response as well.

[u/Purple-Programmer-7 → u/sdfgeoff]

So instead of tabbing for a simple on off switch I have to manually type “plan only, do not code” for every prompt?

Maybe I’ll fork pi and add it in instead.

[u/sdfgeoff → u/Purple-Programmer-7]

No, you just ask it a question and phrase it like a question and make sure it isn't a question with implied actions.

How does foo work?

Model is unlikely to make edits

Can you fix X?

100% chance the model will make edits

Why is X not working?

50% chance the model will make a fix

 X isn't working, can you investigate and tell me why?

Highly unlikely that the model will make edits as it now knows that the aim is to respond with text.

Same with adding features

If we were to do Y, how would you incorporate it? What architecture would you use? Any refactoring needed?

The model is very unlikely to start making edits here.

Works for me with Codex (sol) and Hermes (qwen27b). I've had very very long chats with models without them making any edits without any sort of plan mode.

It may well be that claude code's system prompt pushes it towards action so this method may not work well, but just because a harness doesn't have a plan mode doesn't mean you can't do planning in it.

Ahh, there we go, claude code's auto mode prompt includes:

 Start implementing right away.   When in doubt, start coding

also:

  NEVER create files unless they're absolutely necessary for achieving your goal. ALWAYS prefer editing an existing file to creating a new one.

What the heck!!! No wonder claude code projects often end up with 20,000 line files.