Generate SSH Key

For each account, generate a separate SSH key:

ssh-keygen -t ed25519 -C "your-email-for-first-account" -f ~/.ssh/id_ed25519_first
ssh-keygen -t ed25519 -C "your-email-for-second-account" -f ~/.ssh/id_ed25519_second

• -t ed25519: Specifies the type of key (ed25519).
• -C "your-email-for-first-account": Adds a comment for identification.
• -f ~/.ssh/id_ed25519_first: Specifies the file name for the private key (~/.ssh/id_ed25519_first) and the public key will automatically be named ~/.ssh/id_ed25519_first.pub.

Add SSH Keys to the Agent

eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519_first
ssh-add ~/.ssh/id_ed25519_second

List Existing SSH Keys

Run the following command to list your SSH keys:

ls ~/.ssh

You should see files like id_ed25519, id_ed25519.pub, id_ed25519_first, id_ed25519_second, or similar. The .pub files are the public keys.

Add the Public Keys to GitHub

Copy each public key to GitHub:

cat ~/.ssh/id_ed25519_first.pub
cat ~/.ssh/id_ed25519_second.pub

Add these keys to the respective GitHub accounts under Settings > SSH and GPG keys.

Configure ~/.ssh/config

Create or edit the ~/.ssh/config file to define host aliases:

nano ~/.ssh/config

Add the following lines:

Host github-first
    HostName github.com
    User git
    IdentityFile ~/.ssh/id_ed25519_first

Host github-second
    HostName github.com
    User git
    IdentityFile ~/.ssh/id_ed25519_second

Save the file.

Test SSH Keys

Use the following command to test your SSH keys with GitHub.
For the first account:

ssh -T git@github-first

You should see a message like:

Hi username! You've successfully authenticated, but GitHub does not provide shell access.

Check for the second account too!
If you encounter any issues, ensure:

• The correct SSH keys are added to the agent.
• The ~/.ssh/config file is correctly set up.

Clone Repositories

Use the alias for the desired account:

git clone git@github-first:username/repository.git
git clone git@github-second:username/repository.git

Update an Existing Repository's Remote

If you're switching remotes:

git remote set-url origin git@github-first:username/repository.git
git remote set-url origin git@github-second:username/repository.git

Push Code from VS Code(or any code editor)

1. Open the repository folder in VS Code.

2. Ensure the correct remote is set:

git remote -v

3. Commit and push code:

git add .
git commit -m "Your commit message"
git push origin main