Managing Multiple GitHub Accounts with SSH

Problem

When working with both personal and work GitHub accounts on the same machine, you need a way to:

• Authenticate to different GitHub accounts
• Automatically use the correct SSH key for each repository

Solution Overview

Create separate SSH keys for each account and configure SSH to use the appropriate key based on a custom host alias.

Setup

1. Generate SSH Keys

# Work account
ssh-keygen -t ed25519 -C "your-work-email@company.com" -f ~/.ssh/id_ed25519_work

# Personal account
ssh-keygen -t ed25519 -C "your-personal-email@example.com" -f ~/.ssh/id_ed25519_personal

2. Configure SSH

Create or edit ~/.ssh/config:

# Work account
Host github.com-work
    HostName github.com
    User git
    IdentityFile ~/.ssh/id_ed25519_work
    IdentitiesOnly yes

# Personal account (default)
Host github.com
    HostName github.com
    User git
    IdentityFile ~/.ssh/id_ed25519_personal
    IdentitiesOnly yes

3. Add Public Keys to GitHub

Copy each public key and add to the respective GitHub account under Settings → SSH and GPG keys → New SSH key.

cat ~/.ssh/id_ed25519_work.pub      # Add to work GitHub
cat ~/.ssh/id_ed25519_personal.pub  # Add to personal GitHub

4. Test Connections

ssh -T git@github.com-work   # Should show work username
ssh -T git@github.com        # Should show personal username

Usage

Cloning Repositories

# Work repositories - use the custom host alias
git clone git@github.com-work:global-trust-networks/gtn-mongolia.git

# Personal repositories - use standard host
git clone git@github.com:daze17/dotfiles.git

Converting Existing Repositories

# Check current remote
git remote -v

# Update to work account
git remote set-url origin git@github.com-work:global-trust-networks/repo-name.git

Git User Configuration

Set different commit identities per repository:

# Inside work repo
git config user.name "Your Name"
git config user.email "your-work-email@company.com"

# Inside personal repo
git config user.name "daze17"
git config user.email "your-personal-email@example.com"

Directory-Based Config (Optional)

Add to ~/.gitconfig for automatic configuration by directory:

[includeIf "gitdir:~/work/"]
    path = ~/.gitconfig-work

[includeIf "gitdir:~/personal/"]
    path = ~/.gitconfig-personal

Then create ~/.gitconfig-work:

[user]
    name = Your Name
    email = your-work-email@company.com

And ~/.gitconfig-personal:

[user]
    name = daze17
    email = your-personal-email@example.com

SSH Agent Setup (Optional)

Add keys automatically on shell startup. Add to ~/.bashrc or ~/.zshrc:

# Start ssh-agent if not running
if [ -z "$SSH_AUTH_SOCK" ]; then
    eval "$(ssh-agent -s)"
fi

# Add keys
ssh-add ~/.ssh/id_ed25519_work 2>/dev/null
ssh-add ~/.ssh/id_ed25519_personal 2>/dev/null

Troubleshooting

Quick Reference