GitHub Permission denied (publickey)

1. About the error
2. Why do I see this error
3. Solution
4. Test the connection
5. Generate a key if you don't have one
6. Add the public key to GitHub
7. Load the key into the agent
8. Wrong remote protocol

#About the error

git@github.com: Permission denied (publickey).
fatal: Could not read from remote repository.

You're connecting to GitHub over SSH, and GitHub rejected the authentication because none of the keys your client offered matches a key on your account.

#Why do I see this error

• You haven't generated an SSH key yet.
• The public key isn't added to your GitHub account.
• The key exists but isn't loaded into the SSH agent.
• You're using an HTTPS-style setup but a remote that expects SSH (or vice versa).

#Solution

#Test the connection

GitHub has a dedicated endpoint for this. A success looks like a greeting, not a shell:

ssh -T git@github.com

If it says Hi <username>!, your key works and the problem is the repository remote, not auth. If it says Permission denied, continue below.

#Generate a key if you don't have one

ssh-keygen -t ed25519 -C "you@example.com"

Press enter to accept the default location (~/.ssh/id_ed25519).

#Add the public key to GitHub

Copy the public key (.pub) and paste it into GitHub under Settings → SSH and GPG keys → New SSH key:

cat ~/.ssh/id_ed25519.pub

#Load the key into the agent

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

#Wrong remote protocol

If your account is set up for SSH but the repo was cloned over HTTPS (or the reverse), switch the remote URL:

git remote set-url origin git@github.com:you/repo.git

For the general server-side version of this error (your own servers rather than GitHub), see SSH Permission denied (publickey).