README.md

To symlink SSH_AUTH_SOCK on boot to system-wide switch the value from default ssh agent:

1. Change /opt/homebrew/ to the correct homebrew path (/opt/homebrew is for Apple Silicon and /usr/local for x86)
2. Change the ssh agent as needed, this example uses https://github.com/FiloSottile/yubikey-agent
3. Save as ~/Library/LaunchAgents/link-ssh-auth-sock.plist
4. Run launchctl load -F ~/Library/LaunchAgents/link-ssh-auth-sock.plist

Technique taken from: https://evilmartians.com/chronicles/stick-with-security-yubikey-ssh-gnupg-macos

link-ssh-auth-sock.plist

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
  <key>Label</key>
  <string>link-ssh-auth-sock</string>
  <key>ProgramArguments</key>
  <array>
    <string>/bin/sh</string>
    <string>-c</string>
    <string>/bin/ln -sf /opt/homebrew/var/run/yubikey-agent.sock $SSH_AUTH_SOCK</string>
  </array>
  <key>RunAtLoad</key>
  <true/>
</dict>
</plist>