On August 13, 2021, GitHub permanently disabled account password authentication for all authenticated Git and CLI operations. This security update meant you could no longer use your standard GitHub login password when executing terminal commands like git push or git clone over HTTPS.
You could only use a personal access token or SSH to execute commands from the terminal. This guide walks through generating an SSH key, adding it to GitHub, and confirming everything works on Linux or macOS.
Once it's set up, git push and git pull just work: no prompts, no tokens to copy-paste, no expiring credentials to renew.
What You'll Need
A terminal (Linux, macOS, or Git Bash/WSL on Windows)
A GitHub account
5 minutes
Step 1 — Check for an Existing SSH Key
You may already have one. Check before generating a new key:
ls -al ~/.sshIf you see a pair of files like id_ed25519 and id_ed25519.pub, you have a key already and can skip to Step 3. If the directory doesn't exist or is empty, move on to Step 2.
Step 2 — Generate a New SSH Key
GitHub recommends the Ed25519 algorithm; it's faster and just as secure as RSA, with a much shorter key.
ssh-keygen -t ed25519 -C "your_email@example.com"Replace the email with the one tied to your GitHub account. You'll be prompted for:
A file location — press Enter to accept the default (
~/.ssh/id_ed25519).A passphrase — this is optional, but recommended. It protects your private key if your machine is ever compromised. You'll only need to type it once per session thanks to the SSH agent (next step).
Step 3 — Add Your Key to the SSH Agent
The SSH agent holds your decrypted key in memory so you're not re-entering your passphrase constantly.
eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_ed25519On macOS, if you want the key to persist across reboots via Keychain:
ssh-add --apple-use-keychain ~/.ssh/id_ed25519Step 4 — Copy Your Public Key
You need the public key (.pub file). Never copy the private key.
cat ~/.ssh/id_ed25519.pubSelect and copy the full output, starting with ssh-ed25519 and ending with your email.
On macOS you can copy it directly to the clipboard instead:
pbcopy < ~/.ssh/id_ed25519.pubOn Linux with xclip installed:
xclip -selection clipboard < ~/.ssh/id_ed25519.pubStep 5 — Add the Key to GitHub
Log in to GitHub and go to Settings.
In the sidebar, click SSH and GPG keys.
Click New SSH key.
Give it a descriptive title (e.g., "Work Laptop — Pop!_OS 2026") so you can identify it later if you ever need to revoke it.
Paste your public key into the Key field.
Click Add SSH key.
Step 6 — Test the Connection
ssh -T git@github.comThe first time you connect, you'll see a fingerprint prompt asking whether to continue. Type yes. If everything is configured correctly, you'll see:
Hi your-username! You've successfully authenticated, but GitHub does not provide shell access.That message means it worked. GitHub doesn't offer an interactive shell over SSH, so seeing that response confirms authentication succeeded.
Step 7 — Clone or Switch a Repo to SSH
For a new repository, use the SSH URL (starts with git@github.com:) instead of the HTTPS one when cloning:
git clone git@github.com:your-username/your-repo.gitFor a repo you already cloned over HTTPS, switch its remote to SSH:
git remote set-url origin git@github.com:your-username/your-repo.gitVerify it took effect:
git remote -vTroubleshooting
"Permission denied (publickey)" — Your key likely isn't loaded in the agent, or isn't linked to your GitHub account. Run ssh-add -l to confirm the key is loaded, and double-check the public key was pasted correctly in GitHub's settings.
Connections blocked on port 22 — Some networks (corporate VPNs, some ISPs) block SSH's default port. GitHub offers a workaround using port 443 — see GitHub's official troubleshooting guide if you hit this.
Using multiple GitHub accounts on one machine — You'll need a separate key per account and a ~/.ssh/config file that maps each account to its own key. That's a bigger topic worth its own post if there's interest; let me know.
Wrap-Up
That's it! SSH authentication set up end to end. It's a five-minute task that saves you from re-authenticating constantly, and it's one of those things worth doing on day one of any new machine setup.
