Create an SSH key and add it to GitHub

Fill these in once

Email you use on GitHub

Create the key
Terminal
```
ssh-keygen -t ed25519 -C "you@example.com"
```
Press Enter to accept the default file. Add a passphrase if you like.

Tell your Mac to remember it

Terminal

cat >> ~/.ssh/config <<'EOF'
Host github.com
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/id_ed25519
EOF
ssh-add --apple-use-keychain ~/.ssh/id_ed25519

Copy the public key
Terminal
```
pbcopy < ~/.ssh/id_ed25519.pub
```

Open GitHub and paste it

Terminal

open https://github.com/settings/ssh/new

Check it worked

Test the connection
Terminal
```
ssh -T git@github.com
```
Type "yes" if asked. You should see "Hi ! You've successfully authenticated".

Undo it

Delete the key from this machine
Terminal
```
rm ~/.ssh/id_ed25519 ~/.ssh/id_ed25519.pub
```
Also remove it on github.com/settings/keys.

Create the key
Terminal · Ubuntu / Debian
```
ssh-keygen -t ed25519 -C "you@example.com"
```
Press Enter to accept the default file. Add a passphrase if you like.
Load it into the SSH agent
Terminal · Ubuntu / Debian
```
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519
```
Show the public key, then copy it
Terminal · Ubuntu / Debian
```
cat ~/.ssh/id_ed25519.pub
```
Open GitHub and paste it
Terminal · Ubuntu / Debian
```
xdg-open https://github.com/settings/ssh/new
```

Check it worked

Test the connection
Terminal · Ubuntu / Debian
```
ssh -T git@github.com
```
Type "yes" if asked. You should see "Hi ! You've successfully authenticated".

Undo it

Delete the key from this machine
Terminal · Ubuntu / Debian
```
rm ~/.ssh/id_ed25519 ~/.ssh/id_ed25519.pub
```
Also remove it on github.com/settings/keys.

Create the key
PowerShell
```
ssh-keygen -t ed25519 -C "you@example.com"
```
Press Enter to accept the default file. Add a passphrase if you like.

Start the SSH agent automaticallyRun as administrator

PowerShell

Get-Service ssh-agent | Set-Service -StartupType Automatic
Start-Service ssh-agent

Load the key

PowerShell

ssh-add "$env:USERPROFILE\.ssh\id_ed25519"

Copy the public key

PowerShell

Get-Content "$env:USERPROFILE\.ssh\id_ed25519.pub" | Set-Clipboard

Open GitHub and paste it

PowerShell

Start-Process "https://github.com/settings/ssh/new"

Check it worked

Test the connection
PowerShell
```
ssh -T git@github.com
```
Type "yes" if asked. You should see "Hi ! You've successfully authenticated".

Undo it

Delete the key from this machine
PowerShell
```
Remove-Item "$env:USERPROFILE\.ssh\id_ed25519", "$env:USERPROFILE\.ssh\id_ed25519.pub"
```
Also remove it on github.com/settings/keys.

New to GitHub? I explain it in plain English on Layman Terms.