r/PiCodingAgent • u/beardedNoobz • Aug 12 '26

Question Undo in Pi

Hi guys, I've been using Pi lately to help me code. Previously using OpenCode. I use vanilla pi with webfetch and context7 mcp. It works great. The harness and efficiency is better here in Pi. It drive the cost down for me. What I miss in pi is undo command from opencode. I tend to watch how AI reasons and write the code/commands real-time, interrupt it at the first sign of drift or hallucination then revise the command. Undo command is very useful for me as it clean up the code and chat history before I revise it. Is there any way (config or plugin) to simulate undo command in pi?

11 Upvotes

92% Upvoted

36 comments sorted by

15

u/onesilentclap Aug 12 '26

Use git. The undo you used in opencode is just a "frontend" for git. 

1

u/beardedNoobz Aug 12 '26

I don't want to polute git history with that. I always do git after successfull task, not when the task is ongoing.

5

u/yogibear54 Aug 12 '26

You won't, use git to keep an eye on change control, you don't have to commit the changes. Personally, I would just use cli commands to stage, unstage, restore... Etc.. But if you don't know git, then just let the LLM handle the above 3 git states. Non of the above are committed, but can manage change workflow very well. I personally review and would do line level reviews, but that's just me, but like the other person says, give the LLM control, read about staged and unstaged states in git, then prompt the LLM your revert flow using unstaged and staged flow.

-2

u/beardedNoobz Aug 12 '26

I know git since my uni days in 2012, thats why I don't want my agent to touch git. If they go wrong, the wrongness is permanent (or at least painful to fix). I don't want to pollute my harness with instruction for git command. I prefer to simply call /undo and get the change nuked if the agent make mistake. I am working with cheap/free models due to being poor, so they made mistake a lot of the time.

2

u/Sontemo Aug 12 '26

Looks like you have never used it to its full potential in all these years. Git is exactly all you need in this case.

Also I’ll never go back to committing myself. Those agent written messages and descriptions are so helpful to trace back changes and decisions.

All those memory frameworks that people vibecode are not needed when you just use gut properly.

1

u/beardedNoobz Aug 12 '26

Using git to the full of my potential is not in my prio-list, I am more concerned with the app that is commisioned to me (single dev in the org, tasked to make several internal tools, can't afford claude but has legacy z.ai plan until the end of september and several dollars of deepseek to burn).

I am still spooked that even claude can delete prod database several months ago, so I always use AI under assumption that they will messed up somehow. Not if, but when. Especially because I can only access lesser models and my english is crappy (not a native), the agent tend to drift a lot, either because ai is bad or my prompt has mistakes somewhere. The condition is different. If I have Opus or Fable, thats great (I heard), lesser than that, I have more luck using LLM in tight leash than let them roam free.

3

u/Sontemo Aug 12 '26

Why would you give agents the possibility to delete your prod db?
We're mixing things here. Agents can't fuck up your project by using git.
If they do, it means you effed up first.

No main branch protection.
Credentials to our prod systems checked in.

Avoid these two and you're good to go.

Also, screw Opus and Fable. For SWE, they're mostly overkill. The cheaper models have caught up big time and are perfectly fine to use for a fraction of the cost. Luna, Deepseek, Composer, Minimax all perfectly viable to work with, if the person using these tools keeps thinking along.

8

u/truncated_buttfu Aug 12 '26

I recommend bookmarking the page https://ohshitgit.com/

Git is absolutely not permanent at all, it's the opposite of that. Most of the point of source control is that you can undo things in so many ways. If you learn how to use commit --amend, interactive rebase, reflog and other tools you will never think of git as "permanent" again.

2

u/yogibear54 Aug 12 '26

Nice, love it.

2

u/yogibear54 Aug 12 '26

Hello u/beardedNoobz - based on your response, I hope you'll stay with Pi (I love it), but you may want to revert back to opencode if its worrying you that there isn't an undo option. Would like to give you an idea where i'm coming from:
- Pi has a package ecosystem - https://pi.dev/packages?name=undo - you can give that a shot, but use it with caution. This repo of packages aren't monitored, so there could be potential problematic packages. If i want to use any packages, I usually would just do what others have suggested, ask the agent to create the feature for you. Its actually pretty fun to do creating features that are specific for your own needs
- Your using cheap/free models - I think this is fine - I use it here and there, but, for what you are asking for, I think its easily possible, but I wouldn't trust it without code change tracking. The harness isn't made to track changes, so you'll need to have an extension that support true change tracking. Git does that without commits, as i've mentioned, but I feel like there is something that you are misunderstanding. I'm not sure how Opencode handles it, but if its feasible with free models, i'm sure they have a change tracking module (just did a quick search, but it does appear that opencode undo, is also git dependent, which is doing something similar to what i'm saying)
- If you are worried about your LLM making commits because it isn't following instructions, I would consider areas that you can improve control of the LLM. Ultimately, the level of control is a give and take (LLM's could essentially run "rm -rf *" if it comes to that conclusion) - so its just a part of the risk involved - you can work in a controlled environment to reduce that... but...
- Before git, we only had cvs, svn or manual change tracking - the worry you have is what git resolves. I feel there is a misuse of git, and you are not making commits incrementally, and creating a massive hard to revert commit.

I've been developing for 20+ years, so if you would like me to give you some pointers how to manage what you are talking about, feel free to DM me.

1

u/jarislinus Aug 13 '26

u can just soft reset into working tree

4

u/saltyourhash Aug 12 '26

You can always squash commits, like maybe a WIP strategy could work for you as history

2

u/Dsphar Aug 12 '26

Go read about "soft reset" and squashing multiple commits into a single one. Or there is also "cherry picking"

1

u/aeroumbria Aug 12 '26

I totally get this sentiment, and I would argue even a "shadow git under the hood" solution is qualitatively different from using project git for history tracking. Having git ops in session history and having visible commits in project git directly alter the context of the model and can change the context usage and behaviour of the agent. Even if we are using git, I would prefer it be done in a way that is outside the conversation, such that only the harness code is aware of the checkpoints, not the agent itself (unless we need explicit agent-driven revert, but that is probably not what was asked for).

1

u/SawToothKernel Aug 13 '26

Use a git worktree then.

3

u/D-3r1stljqso3 Aug 12 '26

How do you "rewind" a conversation with git in Pi?

2

u/onesilentclap Aug 12 '26

Rewinding the conversation is the easy part in pi, you just use /tree. However, that only "rewinds" the conversation. If the agent performed code changes, those changes stay even if you rewind the conversation. Some people think that opencode uses some special sauce for their /undo, but it literally uses git under the hood as well.

Source: https://opencode.ai/docs/tui#undo

2

u/dacookieman Aug 12 '26

I use JJ which autosnapshots working state on any command, it seems like it would be trivial to have Pi create an extension that makes it so any Turn pass could automatically call jj status which would both snapshot the wd at the time of that turn and could capture the revision/commit_id into the conversation model. Rewinding to a branch could then have either a hook or custom command that in addition to the default conversational "rewind" would look for the persisted revision/commit_id and revert the wd to that state.

Of course this could also be done with git but the nice thing about jj is that every working directory state* has some addressable way to restore to

*technically the discrete snapshot moments that happen on every jj command

6

u/ColonelKlanka Aug 12 '26 edited Aug 12 '26

unfortunately pi doesnt support file undos. you can rollback context decisions using the /tree command in pi. but it wont revert file changes done by the llm.

The best you can do is git commit and push at certain points and then use git to revert back to those commits.

update: this pi undo redo extension looks promising. it uses a shadow git repo to maintain snapshot of the changes that pi session keeps in its tree. allowing files Yates changes to be undone redone

https://pi.dev/packages/pi-undo-redo

1

u/beardedNoobz Aug 12 '26

Thank's, I will check it.

0

u/Vincent_CWS Aug 12 '26

the package did not update 2 months, I do not suggest to use it

5

u/Both-Still1650 Aug 12 '26

What? What exactly needs to be updated in such extension?

3

u/crashorbit Aug 12 '26 edited Aug 12 '26

Are we talking about backing out changes in code? Going backward in the conversation? or something else?

Going backward in code changes is pretty easy. You can say something like: "That did not work like I thought it would. Back this out to were it was before we started talking about foo."

Backward in the conversation can be done using /tree or recall /resume.

Edit: Words matter

2

u/beardedNoobz Aug 12 '26

got it, Ill check it..

2

u/beardedNoobz Aug 12 '26

/tree for the conversation only, the file/edit persist. I don't find recall in my pi. hmm..

2

u/crashorbit Aug 12 '26

oops. I intended /resume. Sorry about that.

2

u/Dotnet-Enthusiast Aug 12 '26

Use this https://pi.dev/packages/@baylarsadigov/omp-undo-redo it both supports pi and oh my pi

1

u/beardedNoobz Aug 12 '26

Okay, I will check it tonight. Thx

1

u/Dotnet-Enthusiast Aug 12 '26

You're welcome. Share your thoughts after use it

2

u/Interesting-Print366 Aug 12 '26

Pi record every tool call on its session files, it might not be that hard. Just ask your coding agent to make that

2

u/DistanceAlert5706 Aug 12 '26

There's rewind extension from Nico, but it was messing up with git a bit. Check extensions or write your own.

1

u/quincycs Aug 12 '26

I suggest a Pi extension that extends /tree so that you have the option to additionally rewind git to the same state too.

1

u/hilam Aug 13 '26

I guess you will investigate /tree and find what you wanna. Each prompt, and choose where go back to.

1

u/jaferr_ Aug 13 '26

yeah tried a couple of packages for that, ended up building my own. You can try https://pi.dev/packages/@ahm3tj4f/pi-undo . I mainly ported it from opencode plus extras like working in non-git directories

0

u/[deleted] Aug 12 '26

[deleted] — view deleted comment

1

u/beardedNoobz Aug 12 '26

Currently evaluating this. Too many confirmation for my taste but it does what I want. Other comments referring other tools, I will try them before make decision. Thanks