@microsoft-github-policy-service agree

whoa

This is a long-awaited feature! Thanks @joexue!

FYI: I am working with reduced staffing at the moment, so reviews may be slow to come. I apologize for that.

Is there a nightly build with this PR to test?

Is there a nightly build with this PR to test?

Your best bet is to build this locally. Once it merges, it will be available on the Canary channel though.

Is there a nightly build with this PR to test?

Your best bet is to build this locally. Once it merges, it will be available on the Canary channel though.

I tried to find the build guide, but couldn't find one. Do you have the link handy?

Is there a nightly build with this PR to test?

Your best bet is to build this locally. Once it merges, it will be available on the Canary channel though.

I tried to find the build guide, but couldn't find one. Do you have the link handy?

README.md ->Developer Guidance @iDarshan

Hi @joexue! Thanks for doing this! I published a build for the team to test internally and we've got a few notes we want to share with you 😊

• Notes/Reactions:
  • Settings menu item is gone from the dropdown
  • It makes your existing window a special "tmux only" window; it disables the menu, but it doesn't disable the key bindings, so you can still split in non-tmux panes
  • Scrollbars are gone? I guess scrolling is server side
• Requested changes:
  • [Bug] can't type in an older pane after splitting panes
  • tmux tabs should not be draggable into a new window
  • Add a setting to Profile > "Terminal Emulation" page that disables this (it should be disabled by default)
  • Bug: Closing a tab/pane will not kill the instance on the server side
  • Add a feature flag to features.xml (Guidance)
  • [Architectural notes] We should see if we can't just model a tmux pane as a connection so we don't need to pump output into the terminal from the App layer

Overall, this is a really exciting feature and we're excited to see it land! Let us know if you need any guidance or additional comments on any of the thoughts above. 😊

CC @DHowett @lhecker @zadjii-msft

Hi @joexue! Thanks for doing this! I published a build for the team to test internally and we've got a few notes we want to share with you 😊

• Notes/Reactions:

  • Settings menu item is gone from the dropdown
  • It makes your existing window a special "tmux only" window; it disables the menu, but it doesn't disable the key bindings, so you can still split in non-tmux panes
  • Scrollbars are gone? I guess scrolling is server side

Scrollbars are gone is by design, I put the comment in the code, since we want to make local panes size match remote(tmux) panes size, but each split, tmux just lost 1 character to use it as separator, if we have side scrollbars, we cannot make two side's size match. To meet this, the padding size is changed too.

As the menu, it is because I tried to touch as less code as I can to do the job. So give the tmux a separate UI system. I described in the PR, this could be improved and should integrated into the present UI/menu system.
But, I think we can skip this ugly stage, directly change the code to make the tmux control mode work with present UI/menu system. I will address this, those +button/flyout splitting menus specifically for tmux will be gone.

• Requested changes:

  • [Bug] can't type in an older pane after splitting panes

I did not see this bug, to help me to reproduce it here, could you describe your env? how do you connect to tmux server? what is the tmux version?

• tmux tabs should not be draggable into a new window

Sure, let me fix it.

• Add a setting to Profile > "Terminal Emulation" page that disables this (it should be disabled by default)

Sure, let me look it.

• Bug: Closing a tab/pane will not kill the instance on the server side

This is by design, remote pane should close by quit it's app. but this is arguable, if we think close local pane should close remote pane too, it is easy and feasible.

• Add a feature flag to features.xml (Guidance)

Sure. Fair enough.

• [Architectural notes] We should see if we can't just model a tmux pane as a connection so we don't need to pump output into the terminal from the App layer

Please provide the idea, I can try to implement it.

Overall, this is a really exciting feature and we're excited to see it land! Let us know if you need any guidance or additional comments on any of the thoughts above. 😊

CC @DHowett @lhecker @zadjii-msft

Thanks!

Since this PR is a bit big, another option is we split it into two or three parts to make it easy to review and integrate. Such as
part 1: infra libs(parser, TermControl, Terminal, ControlCore)
part 2: TmuxControl
part 3: integrating and UI/Menu

What do you think, split it or just keep as it is?

@carlos-zamora @DHowett @lhecker @zadjii-msft
All comments are addressed, please try again.

Thanks

@joexue Yep, don't worry about the Needs-Author-Feedback. Even if the PR gets automatically closed.

As long as you keep your fork up, and your branch open, we prefer to work on your PR like this.

That way, you get credit for doing the bulk of the work -- and we can thank you appropriately when it ships. We would literally not have started on this without you. :)

/azp run

/azp run

/azp run

/azp run

I tried to test this and seems like its not working

root@fst:~# lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 24.04.3 LTS
Release:        24.04
Codename:       noble
root@fst:~# tmux ls
0: 1 windows (created Sat Jan 31 02:31:00 2026)
root@fst:~#
root@fst:~# tmux -CC attach
root@fst:~#
root@fst:~# tmux -V
tmux 3.4
root@fst:~#

Anything special need to be done to try this?

Anything special need to be done to try this?

You probably need to turn it on in Settings.

Anything special need to be done to try this?

You probably need to turn it on in Settings.

Which settings? in Terminal or System settings? Do you have path to setting?

Which version of Terminal are you using? Did you compile it yourself? Since this pull request is still open and has not been accepted, you would need to have compiled it yourself.

Which version of Terminal are you using? Did you compile it yourself? Since this pull request is still open and has not been accepted, you would need to have compiled it yourself.

Compiled myself. It took hell of a time to figure out compilation steps. it always fails due to vcpkg. Readme needs to include steps around vcpkg failure.

Oh dang, that's a new failure state we haven't heard of. If you remember what you had to do, would you mind sharing? It's supposed to use the vcpkg install that comes with VS, but if that's broken it will try a couple other things.

I think this PR puts the control mode toggle into Terminal's in-app settings, profile (or defaults), advanced.

Enable this setting to allow Tmux Control mode:
Settings->Defaults->Additional Settings->Terminal Emulation->Allow Tmux Control

I have tested this briefly and here are the basic bugs:

• Cannot resize the panes
• Alt + (+ button) click always splits the current pane vertically, no way to split pane horizontally.