Show HN: Rmux – A programmable terminal multiplexer with a Playwright-style SDK(github.com)

105 pointsby shideneyu4 hours ago19 comments

eddyaipt7 minutes ago
The Playwright-style snapshot/wait layer is the interesting part to me. A lot of agent terminal automation still breaks because the tool can send keys but can't prove which pane or terminal state it actually reached. Stable pane IDs plus explicit waits should make replay and debugging much saner than the usual grep+sleep loops.
pama2 hours ago
Congrats on the launch. If emacs was unavailable and I needed tmux, I would try it. I am old school, and use emacs daemons for all shell multiplexing. The agents dont need explanations and know how to use emacsclient to create, read, or send inputs to named buffers that run the shells. Elisp is powerful, so manipulating windows is a breeze. Lots of people on tmux would benefit from this design though.
florianist3 hours ago
The paragraph on the website inviting us to switch to rmux from tmux claims that tmux is programmed in C++. tmux is made in C.
- shideneyu3 hours ago
  wupsy ! thanks, I just fixed it
kloud2 hours ago
Cool project, I like the idea of having tmux-compatible CLI. I used Zellij to get better UX, but many agent tools integrate with tmux. This way agent tools can still integrate tmux as a defacto standard for programmatic interface while having better interface for users.
But I wonder if tmux/rmux design is suboptimal since it couples session persistence and window management together. Do you have an opinion the design which separates the responsibilities? An example that pioneered this approach is abduco, and libghostty-based zmx being a modern implementation.
- shideneyuan hour ago
  I thought I was too zealous because I created 11 crates respecting single responsibility principles.. I would have been all in to risk it further and separating responsibilities for session and window management but it would have diverged too much from tmux. I wanted a 1-1 port for now
  - kloudan hour ago
    Fair point, given it is more unconventional design, it is a riskier way in order to get something that works.
Sirental4 hours ago
The website is a little too obviously made by Claude. The first thing I noticed is the classic "pill with pulsing green dot that says something is active or live" claudism.
- shideneyu3 hours ago
  The video of the front page is assisted by AI, I am not a vfx artist; please check rmux code architecture instead, I put a lot of efforts on it
  - powvansa minute ago
    For what it's worth I genuinely loved your landing page. I casually clicked through and got an immediate unexpected chuckle at the giant animated crab.
    It's obviously AI assisted but I interpreted it as a nod to itself on that and really appreciated it.
- ookblah2 hours ago
  "site made by ai" is the new "bootstrap template" criticism that honestly gets tiring after a while. just read the content.
- redrove4 hours ago
  I’m genuinely interested in what you find to be the problem with that?
  It’s a landing page.
- cultofmetatron3 hours ago
  commonlisp (sbcl) is one of the best sleeper techs out there. one of those if you're in the know type industry secrets. part of it is because their website looks like something out of the 90's. clearly having a nice website and some level of marketing is necessary to get adoption. Im more than happy to see devs use AI to automate that so they have more time to focus on their creations.
  - alcasa2 hours ago
    Isn't lisp getting advertisement every couple months here or so. After so many decades I don't believe the reason lisp doesn't have traction is just marketing.
- Oras3 hours ago
  and why this is a problem? I found the landing page covering exactly what the product does, with nice demos and examples.
- stefanfisk3 hours ago
  Not to mention those absolutely horrible scroll animations.
  - shideneyu3 hours ago
    you don't like parallax effects ? maybe I'm too 2010 for you
- jarym3 hours ago
  So?
  - shideneyu2 hours ago
    @jarym what don't you like with the homepage ? I am curious how I can improve
    FergusArgyll2 hours ago
    I like it
btownan hour ago
Very cool! I think the hype around “agents are so good that you never actually need to see the underlying commands they are running or interact with the terminal session that they’re running” misses out on a lot of very important use cases, particularly around long running processes that may be shared across multiple agents. This will be very cool to see how best practices evolve!
- shideneyuan hour ago
  Same ! TUI are becoming more and more mainstream so there is a need for automated multiplexing , not used by humans but by programs (and agents)
cultofmetatron3 hours ago
a week ago I was using cmux but its osx only and doen't work on remote terminals. then I switched to herdr which is great so far except its not s great at managing panes. I can't move them around or change ordering. now another terminal multiplexer. I'm getting whiplash.
all that said, none of the existing solutions are perfect and rust codebases are nice. how easy is it to reorder panes? is there a cli that lets me control the panel layout via a skill file and allow my opencode session to target and send data to other panes?
- qudat2 hours ago
  I built https://zmx.sh to make it easier to interact with your terminal sessions programmatically. 1 window = 1 session which might feel like a negative but it makes programmatic access easy and agents can use it just by pointing it at the zmx help command. Basically, an agent just needs 2 commands (run and write) for full control and the commands are synchronous so you don’t need to do any polling.
- Oras3 hours ago
  I started using cmux a month ago and it had made my life a lot easier. Finally I have a pane with all my projects open all the time, I can switch between them, have multiple terminals for each one.
  What do you mean by remote terminals?
  - cultofmetatron3 hours ago
    my plan is to eventually move my entire workflow to a remote workmachine over ssh. with kernal, I can automate all my smoketests entirely from a headless machine rendering my laptop overkill to run agentic workflows. I'd rather be using it to watch movies, learn new stuff or hand code in my downtime. if your workflow requires cmux, you're stuck running your agents on your local machine.
    To be clear, That doesn't make cmux bad. if you WANT to do everythign on your mac, cmux is fantastic. its just not designed with the remote ssh control use case in mind.
    lawrencechen2 hours ago
    I'm one of the creators of cmux. I'm moving a lot of my own dev work to Mac Minis, so I'm starting to feel quite a lot of the pain you mentioned... will try to make this better!
- shideneyu3 hours ago
  no skill file, you get the same 90 commands of tmux. and if you build a rust app you can have many more cool stuff like "wait for" some text to appear, asyncly
  - cultofmetatron3 hours ago
    well it looks great so far but Its a no go for me for now until you have at least a cli that a coding harness can use to drive it. thats going to be the killer feature going forward for all these multiplexers. last week I vibecoded a plugin that lets me open a line specific input box that sends the context of my code along with my prompt into my opencode session running on a seperate pane. its a game changer when it comes to moving faster.
    excited to check back in on the progress as you work on it though! I think these kinds of tools are going to be much more relevant going forward as we all move to agentic workflows.
    shideneyu3 hours ago
    ok will check it out then ! Thank you, putting it on my todo list
- 3 hours ago
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0x1ceb00da2 hours ago
Getting this error when installing from git bash:
$ curl -fsSL https://rmux.io/install.sh | sh rmux install: unsupported OS: MINGW64_NT-10.0-26200
notorandit2 hours ago
Scriptable terminal multiplexer?
Interesting portable scripting thingy. But it would only work with portable tools, not just everything. Especially with Windows tools.
- shideneyuan hour ago
  I wrote it for rust apps in mind, same usecase as for Ratatui. You’re right maybe I need to expose more tools with the cli
cat-whisperer2 hours ago
I used to use ghostty's applescript and built that into a claude skill. It worked like a charm. But this feels super interesting for programmability
luizfwolf3 hours ago
I found the project quite interesting but what's the advantage over just using tmux with a hotkey to send keys?
- shideneyu3 hours ago
  windows support, and the sdk. native async "wait until" something appears on your terminal, so you don't spam send-keys
- 3 hours ago
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kosolam3 hours ago
Hey, I automate tmux all the time with send keys and capture.. how is your project improves vs tmux or zellij?
- shideneyu3 hours ago
  rmux is much faster than tmux or zellj, I did some internal benchmark and it's promising. rmux is a multiplexer engine, meaning that you can rewrite entirely zellij using rmux.. I created a mini zellij in a few hundred lines of rust. You can check the demoes on the repo
  - kosolam3 hours ago
    But wait, I’m a user of tmux or zellij which for me was basically another tmux and I went back to tmux eventually. I’m not looking to develop another tmux or something. Is this project more of a library to create tmux like apps?
    shideneyu2 hours ago
    As of today you can replace tmux by rmux. Its behavior should be 1-1 iso; tmux is more stable though, it has been battle tested with a dozen of years of edge cases refinement. rmux is a faster and more elegant clone of tmux + windows support + programmable sdk
- Galanwe3 hours ago
  I don't get it as well, everything mentioned in the readme is already trivially possible with tmux or zellij
  - shideneyu3 hours ago
    windows support + async + public sdk. You can rewrite zellij with rmux, but not the opposite. rmux is a multiplexer engine
- noodletheworld3 hours ago
  I mean, the obvious immediate answer is “windows”, which tmux flat out doesn't support (except via WSL and a shared mount).
- 3 hours ago
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yes_but_noan hour ago
Floating panes seems not possible, or are they?
- shideneyuan hour ago
  Not part of the current version, it’s on my roadmap :)
small_model4 hours ago
Never had the need to do playwright automation for tmux, so not sure why I would use this above tmux which works well.
- shideneyu3 hours ago
  with rmux you can finally do acceptance/integration tests on your terminal user interfaces. tmux is made for humans, rmux is made for both humans and machines
DeathArrow2 hours ago
1. ask Claude to rewrite X in Rust
2. ask Claude to make a website and claim R is better than X because it's Rust
3. advertise on HN, X and Reddit
4. ???
5. profit!
- miroljub2 hours ago
  If the tokens are already burned, it's better for the environment to share the result for everyone to use it.
- 2 hours ago
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elromulous3 hours ago
Can someone describe the pros/cons vs zellij?
- shideneyu3 hours ago
  You can rewrite Zellij entirely with rmux , that's the main difference. I put a demo on the repo. Because rmux is an engine. I wrote it to be the multiplexer of multiplexers
4 hours ago
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nikhilpareek133 hours ago
[dead]
2 hours ago
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