Yeah, when you had multiple agents working on the same machine, branch isolation was no longer sufficient. A repository folder can only be on one branch at a time.
A worktree is basically equivalent to a cp -R + git branch, which allows this new workflow to occur.
I loved this particular historical insight as to why git worktree was added in 2015 -
Before worktrees, kernel developers faced a major inconvenience when switching contexts (e.g., stopping feature work to fix an urgent bug on a release branch).
Running git stash and switching branches alters timestamps on thousands of files. This forces the build system (make) to perform a full re-compile, which can take up to an hour on large kernels.
I rather like Ace better because the key problem right now is teams not working together and shipping the wrong things. When AI can generate the code, then it feels like product should be bringing the functional vocabulary and grammar while the engineering team provides the technical grammar to build the right thing.
This app is just another "let me talk to product, copy their convo, go off and build this in isolation with an agent" which I think is directionally wrong.
The "rooms" or "streams" should be multi-player instead of product looking at it at the end saying "no, go fix that" and dev copies text from one source and pastes into another.
Unrelated to the feature itself, but remember a few months ago when someone posted Github's beta feature for stacked PRs, and a ton of people slammed them for releasing a seemingly vibe-coded site? To quote Mitchell Hashimoto, "One of the most requested GitHub features in years and the website looks like it was designed by someone 9 years into a 2 year community college program."[1]
When opening the posted link, my first thought was "imagine if the stacked PRs site had the same amount of effort put into it as the Github Copilot App site". They clearly have other preview features on this site already, so maybe I'm just confused on why stacked PRs got some b-grade announcement site. The obvious answer is "copilot", but I'm still curious.
Target market for stacked PRs are ICs who don't have much decision making power and let's be real do not care too much about the look and feel of a "launch site" for the feature. It's also something few if anyone is making a purchasing decision over.
Target market for copilot includes people with actual purchasing power and also many new users where this is an actual make or break feature. So this is worth the investment into design while stacked PRs is questionable. I actually question why they bothered with anything more than a blog post at all for stacked PRs (looking at the post it doesn't seem like too too much more than a blog post though).
I know it has the same functionality, but it also looks like the Codex app which looks like Cursor Agents! Are they sharing some VS Code primitive here?
It's kind of interesting that everyone is going for the desktop app format now.
These desktop agentic coding tools are a large UX step up from the CLIs, but I still think the future is going to be remote development as the coding agents start running for hours at a time. Building a desktop app seems short-sighted as it would just lock them out of the remote option completely.
Doesn't lock you out at all. Codex already had a companion app for mobile so you can send prompts to your desktop app while you go about your business. The infrastructure is there. Server might move from your desktop to cloud at some point but not much changes. Still needs somewhere to run.
Who would have thought that git worktree is the technology of the year 2026?
Yeah, when you had multiple agents working on the same machine, branch isolation was no longer sufficient. A repository folder can only be on one branch at a time.
A worktree is basically equivalent to a cp -R + git branch, which allows this new workflow to occur.
I loved this particular historical insight as to why git worktree was added in 2015 -
Before worktrees, kernel developers faced a major inconvenience when switching contexts (e.g., stopping feature work to fix an urgent bug on a release branch).
Running git stash and switching branches alters timestamps on thousands of files. This forces the build system (make) to perform a full re-compile, which can take up to an hour on large kernels.
And the team behind opencode is working on an alternative https://github.com/anomalyco/rift
Gitbutler still a better option than any worktree like variant
Looks good, but after pricing change I have already used 26% this month with very light usage.
Last month I used Copilot heavily, much much more than I usually do, but did not manage to use more than 58%.
That looks pretty close in shape to the early Ace project Maggie Appleton demonstrated last month.
Edit: This short talk – https://maggieappleton.com/zero-alignment
I rather like Ace better because the key problem right now is teams not working together and shipping the wrong things. When AI can generate the code, then it feels like product should be bringing the functional vocabulary and grammar while the engineering team provides the technical grammar to build the right thing.
This app is just another "let me talk to product, copy their convo, go off and build this in isolation with an agent" which I think is directionally wrong.
The "rooms" or "streams" should be multi-player instead of product looking at it at the end saying "no, go fix that" and dev copies text from one source and pastes into another.
Unrelated to the feature itself, but remember a few months ago when someone posted Github's beta feature for stacked PRs, and a ton of people slammed them for releasing a seemingly vibe-coded site? To quote Mitchell Hashimoto, "One of the most requested GitHub features in years and the website looks like it was designed by someone 9 years into a 2 year community college program."[1]
When opening the posted link, my first thought was "imagine if the stacked PRs site had the same amount of effort put into it as the Github Copilot App site". They clearly have other preview features on this site already, so maybe I'm just confused on why stacked PRs got some b-grade announcement site. The obvious answer is "copilot", but I'm still curious.
[1] https://x.com/mitchellh/status/2043788123008868600
Target market for stacked PRs are ICs who don't have much decision making power and let's be real do not care too much about the look and feel of a "launch site" for the feature. It's also something few if anyone is making a purchasing decision over.
Target market for copilot includes people with actual purchasing power and also many new users where this is an actual make or break feature. So this is worth the investment into design while stacked PRs is questionable. I actually question why they bothered with anything more than a blog post at all for stacked PRs (looking at the post it doesn't seem like too too much more than a blog post though).
I know it has the same functionality, but it also looks like the Codex app which looks like Cursor Agents! Are they sharing some VS Code primitive here?
It's kind of interesting that everyone is going for the desktop app format now.
These desktop agentic coding tools are a large UX step up from the CLIs, but I still think the future is going to be remote development as the coding agents start running for hours at a time. Building a desktop app seems short-sighted as it would just lock them out of the remote option completely.
Doesn't lock you out at all. Codex already had a companion app for mobile so you can send prompts to your desktop app while you go about your business. The infrastructure is there. Server might move from your desktop to cloud at some point but not much changes. Still needs somewhere to run.
You can get to it wherever you want. Copilot CLI is pretty great: https://github.com/features/copilot/cli
There's support in VS Code and Jetbrains IDEs. You can access your agent sessions on the web.
(I work at GitHub, but not on Copilot)
I think their goal is to lock you into their ecosystem instead of using your IDE
They want all your data. A browser doesn't get them that as well.
The desktop app can become a client for their remote cloud agent solution (yuck).
Codex App can spawn/control Codex agents running in the cloud.
Oh nice! I guess they're back to features after finishing tackling their availability issues [1].
[1]: https://github.blog/news-insights/company-news/an-update-on-...
How is this different than the separate Agents app shipping with VS Code?
Other than fewer features.
I’m wondering the same thing, I’m not sure what the purpose of each is?
what app?
In VS Code they’ve added Agent View, which acts like a separate app and looks pretty much identical to this.
they should have spent this engineering time on stability.
So, it's not open source?
Is that a surprise? When has GitHub been known for Open Source?
copilot had such a lead when this whole ai coding thing started. what happened?
Too slow on the move to agents
Plus the whole naming confused people
I still talk to co-workers who think claude code == agents and copilot is just VS autocomplete
Blog post: https://github.blog/news-insights/product-news/github-copilo...