Pair Programming from Anywhere on Earth over SSH

Dec 10, 2018

Let’s admit it: We all hate pair programming, but we have to admit it is effective. In pair programming, we are always exposing ourselves to new methods of programming and are given the opportunity to challenge our own ideas to bring the best solutions to fruition. The fact of the matter is that Pair programming always helps atleast one of the parties involved by teaching one in the pair something or providing a new perspective for the most efficient means to complete a task.

The Issue

Now most of the time we like the person we’re working with, or can atleast tolerate them in person. But in some cases, they are impossible to be around in person! If you’re experiencing the latter (or just prefer to pair program remotely – a much more realistic scenario which also comes with plenty of inherent convenience,) then this tutorial is for you.


There are a couple types of solutions which allow for being able to pair program remotely.

Facetime (or other video/screen sharing solution):

Perhaps the most archaic solution, coding over video chat often leaves one person doing most of the work and the other person squinting at where the other person’s cursor is. This is the solution most conducive to YATS (Yelling At The Screen) when you’re trying to get your partners attention as they’re scrolling through a file and you see the piece of code you were scanning for.

Code Sharing websites like Google Docs

While Facetime solutions succeeds in the personal connection aspect, they fail in being able to allow for easy contribution to the code from either party in the partnership. If you wanted to change the code over voice call, you would need to tell your partner what to change exactly.

The Best of both worlds

Where Code sharing websites succeed, Video sharing solutions fail, and vice versa. You can’t both code at the same time while also being able to see and talk to each other at the same time. The following allows for the best of both worlds, from anywhere in the world.

Using Tmux over SSH combined with

The SSH protocol allows for secure access to your code base from anywhere in the world. Think of it like traveling to your house in an armored car in layman terms. Your data could still be stolen, but it would be insurmountably more difficult to do as opposed to if you were using an insecure transport method (im looking at you Telnet!)

Once you’ve SSH’d into your server, the Tmux application allows a vast expanse of applicable usages besides pair programming.

It can be used as:

  • A more feature-filled replacement for the popular Nohup alternative Screen
  • A Terminal screen multiplexer (points to the the name TMUX)
  • A Pair Programming solution.

Tmux runs a local server which runs any number of terminals that you like. The key here is that the local server can be attached to and disconnected from.

See it in action!

Me attaching and detatching from one of my two live Tmux sessions at will.

The issue here is that to be able to connect to User1’s Tmux session, you must also be logged in as User1.

While most people who pair program together have no problem extending the trust needed to share their password to one another, some people don’t like that level of commitment. This is not an issue! You can use SSH keys to control who has access to your user.

Once someone has an SSH Key to your server, they can simply login using that key in lieu of a password. To delegate someone an SSH key, have them first create a Public/Private key pair using the following:

ssh-keygen -t rsa -C ""

The Password which it asks you to fill out can be ignored or filled depending on whether you feels he won’t let anyone else gain access to the key they just produced. If they’re the type that’s usually late for work after the night of the Powerball winner announcement, they better have a password on their key! This password acts as the second factor of Two-factor auth because the authentication requires something you have (the newly generated key) and something you know (the aforementioned password which decrypts the key)

Have the key creator give you the .pub public key which was created from the previous command output and place the contents of that key in your $HOME/.ssh/authorized_keys file and then restart your SSH service by running sudo service ssh restart. Your SSH process is now loaded with the understanding that anyone who connects with a private key which when Diffie-Hellmann’d with your public key in authorized_keys should result in an affirmative value should be allowed access to your user.

You can control who has access to your user based on the public keys listed in authorized keys. Want to prevent someone from logging in? Simply remove their entry in the file.

To attach to a running Tmux session as shown above, you can run

tmux a

if there is only one session running. Or to pick a specific session, you can run

tmux ls
# Results shown here
tmux a -t <session number picked from above results>

While each of you now has easy access to your compile scripts, and the rest of the codebase, and direct system terminal access, the issue of no video/audio personal connection still exists. is the perfect solution. allows for audio, video, and screen sharing communication all within the browser. No other solution provides the same functionality while also being totally free.

Happy coding!

Honorable Mentions

The vim plugin CoVim, developed by Tufts Computer Scientists, allows for pair programming through vim sessions. The downfall to this is that you must compile your vim from source with python support if it does not already have it, and you also only have access to your partner’s vim session instead of their entire terminal. This means that you do not have access to the rest of the codebase outside of vims !command functionality, which is limiting in usability. You can read more about CoVim in their announcement post here!

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