How to fix ssh-add: No identities found in SSH

First, verify whether SSH keys are already present on your system:

ls -la ~/.ssh

Look for files named id_rsa, id_ed25519, id_ecdsa, or similar. If you see these files, proceed to Step 2. If the directory is empty or does not exist, proceed to Step 3.

Check what keys the SSH agent currently has loaded:

ssh-add -l

This will show all identities the agent has. If you get "The agent has no identities", it confirms the agent is running but needs keys added. If you get "Could not open a connection to your authentication agent", the agent is not running — see Step 4.

If SSH keys do not exist, generate a new key pair:

ssh-keygen -t ed25519 -C "[email protected]"

For older systems that do not support Ed25519, use RSA:

ssh-keygen -t rsa -b 4096 -C "[email protected]"

Press Enter to save to the default location (~/.ssh/id_ed25519), then enter a passphrase for extra security (or leave blank for no passphrase).

Ensure the SSH agent is running and add your private key:

eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519

(Replace id_ed25519 with id_rsa if you generated an RSA key.) If the key has a passphrase, you will be prompted to enter it. After successful entry, run ssh-add -l again to verify the key is loaded.

SSH is strict about permissions for security. Set correct permissions on your keys:

chmod 700 ~/.ssh
chmod 600 ~/.ssh/id_ed25519
chmod 644 ~/.ssh/id_ed25519.pub

If the agent still reports "No identities found" after correcting permissions, try removing and re-adding the key:

ssh-add -d ~/.ssh/id_ed25519
ssh-add ~/.ssh/id_ed25519

To avoid having to manually add keys after each session, add this to your ~/.ssh/config file:

Host *
  AddKeysToAgent yes
  IdentityFile ~/.ssh/id_ed25519

On macOS Sierra and later, also add UseKeychain yes to store the passphrase in the system keychain:

Host *
  AddKeysToAgent yes
  UseKeychain yes
  IdentityFile ~/.ssh/id_ed25519

This ensures keys are automatically added to the agent for future sessions.